Single dose oral oxycodone and oxycodone plus paracetamol (acetaminophen) for acute postoperative pain in adults

Comparing the effects of pre-emptive oxycodone, diclofenac, and gabapentin on postoperative pain after tibia fracture surgery: A randomized clinical trail

Background

Postoperative pain (POP) is one of the most common and most important types of pain.

Objectives

The aim of this study was to compare the effects of pre-emptive oxycodone, diclofenac, and gabapentin on postoperative pain (POP) among patients with tibia fracture surgery.

Materials and Methods

This double-blind three-group randomised controlled trial was conducted in 2023. Participants were 111 candidates for tibia fracture surgery under general anaesthesia. They were randomly allocated to oxycodone, gabapentin, and diclofenac groups through block randomisation. Baseline arterial oxygen saturation, heart rate, and blood pressure were documented before surgery and POP and sedation status were measured during postoperative recovery and 2, 4, 6, 12, and 24 h after surgery. Postoperative opioid analgesic use was also documented. The data were analysed using the SPSS software (v. 20.0) at a significance level of less than 0.05.

Results

Groups did not significantly differ from each other respecting participants' baseline age, gender, body mass index, arterial oxygen saturation, heart rate, blood pressure, and surgery duration (P > 0.05). Moreover, there were no significant differences among the groups respecting POP and sedation status at different measurement time points (P > 0.05), except for six hours after surgery at which the POP mean score in the gabapentin group was significantly less than the other two groups (P = 0.001). Among-group differences respecting postoperative use of opioid analgesics and medication side effects were also insignificant (P > 0.05).

Conclusion

Pre-emptive oxycodone, diclofenac, and gabapentin significantly reduce POP among patients with tibia fracture surgery, though gabapentin may produce more significant analgesic effects. All these three medications can be used for pre-emptive analgesia. Of course, the best pre-emptive analgesic agent is determined based on the opinion of the treating physician.

Genetic background and sex influence somatosensory sensitivity and oxycodone analgesia in the Hybrid Rat Diversity Panel

Opioid use disorder (OUD) is an ongoing public health concern in the United States, and relatively little work has addressed how genetic background contributes to OUD. Understanding the genetic contributions to oxycodone-induced analgesia could provide insight into the early stages of OUD development. Here, we present findings from a behavioral phenotyping protocol using several inbred strains from the Hybrid Rat Diversity Panel. Our behavioral protocol included a modified "up-down" von Frey procedure to measure inherent strain differences in the sensitivity to a mechanical stimulus on the hindpaw. We also performed the tail immersion assay, which measures the latency to display tail withdrawal in response to a hot water bath. Initial withdrawal thresholds were taken in drug-naïve animals to record baseline thermal sensitivity across the strains. Oxycodone-induced analgesia was measured after administration of oxycodone over the course of 2 h. Both mechanical and thermal sensitivity are shaped by genetic factors and display moderate heritability (h2 = 0.23-0.40). All strains displayed oxycodone-induced analgesia that peaked at 15-30 min and returned to baseline by 2 h. There were significant differences between the strains in the magnitude and duration of their analgesic response to oxycodone, although the heritability estimates were quite modest (h2 = 0.10-0.15). These data demonstrate that genetic background confers differences in mechanical sensitivity, thermal sensitivity, and oxycodone-induced analgesia.

Stem cells and pain

Pain can be defined as an unpleasant sensory and emotional experience caused by either actual or potential tissue damage or even resemble that unpleasant experience. For years, science has sought to find treatment alternatives, with minimal side effects, to relieve pain. However, the currently available pharmacological options on the market show significant adverse events. Therefore, the search for a safer and highly efficient analgesic treatment has become a priority. Stem cells (SCs) are non-specialized cells with a high capacity for replication, self-renewal, and a wide range of differentiation possibilities. In this review, we provide evidence that the immune and neuromodulatory properties of SCs can be a valuable tool in the search for ideal treatment strategies for different types of pain. With the advantage of multiple administration routes and dosages, therapies based on SCs for pain relief have demonstrated meaningful results with few downsides. Nonetheless, there are still more questions than answers when it comes to the mechanisms and pathways of pain targeted by SCs. Thus, this is an evolving field that merits further investigation towards the development of SC-based analgesic therapies, and this review will approach all of these aspects.

Comparative Analysis of Inpatient Opioid Consumption Between Different Surgical Approaches Following Single Level Lumbar Spinal Fusion Surgery

STUDY DESIGN

Single-center retrospective cohort study.

OBJECTIVES

To evaluate inpatient MME administration associated with different lumbar spinal fusion surgeries.

METHODS

Patients ≥18 years of age with a diagnosis of Grade I or II spondylolisthesis, stenosis, degenerative disc disease or pars defect who underwent one-level Transforaminal Lumbar Interbody Fusion (TLIF) or one-level Anterior Lumbar Interbody Fusion (ALIF) or Lateral Lumbar Interbody Fusion (LLIF) through traditional MIS, anterior-posterior position or single position approaches between L2-S1. Outcome measures included patient demographics, surgical procedure and approach, perioperative clinical characteristics, incidence of ileus and inpatient MME. Statistical analysis included one-way ANOVA with a post-hoc Tukey Test and Kruskal-Wallis Test with post-hoc Mann-Whitney test. MME was calculated as per the Centers for Medicare and Medicaid Services and previous literature. Significance set at P < .05.

RESULTS

Mean age differed significantly between MIS TLIF (55.6 ± 12.5 years) and all other groups (Open TLIF 57.1 ± 12.5, SP ALIF/LLIF 57.9 ± 9.9, TP ALIF/LLIF 50.9 ± 12.7, Open ALIF/LLIF 58.4 ± 15.5). MIS TLIF had the shortest LOS compared to all groups except SP ALIF/LLIF. Total MME was significantly different between MIS TLIF and Open ALIF/LLIF (172.5 MME vs 261.1 MME, P = .044) as well as MIS TLIF and TP ALIF/LLIF (172.5 MME vs 245.4 MME, P = .009). There were no significant differences in MME/hour and incidence of ileus between all groups.

CONCLUSION

Patients undergoing MIS TLIF had lower inpatient opioid intake compared to TP and SP ALIF/LLIF, as well as shorter LOS compared to all groups except SP ALIF/LLIF. Thus, it appears that the advantages of minimally invasive surgery are seen in minimally invasive TLIFs.

Scheduled, Simultaneous Dosing of Pregabalin, Celecoxib, and Acetaminophen Markedly Reduces or Eliminates Opioid Use After ACL Reconstruction Using Allograft or Hamstring Tendon Autograft: A Randomized Clinical Trial

BACKGROUND

Opioid analgesics continue to be prescribed after ambulatory surgery despite untoward adverse effects, risk of overdose, and association with substance use disorder.

PURPOSE/HYPOTHESIS

The purpose was to investigate the use of a novel system to provide scheduled and simultaneous dosing of acetaminophen, celecoxib, and pregabalin after anterior cruciate ligament reconstruction (ACLR). It was hypothesized that this system would markedly reduce pain and opioid use compared with existing best practice.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Included were 100 patients scheduled for elective, primary ACLR using allograft or hamstring tendon autograft. Selection criteria included age between 18 and 65 years and weight between 65 and 120 kg. Exclusion criteria were a known allergy to any drug used in the study or the use of opioid analgesics before surgery. Patients in the intervention group received a blister pack with scheduled, simultaneous doses of acetaminophen, celecoxib, and pregabalin; patients were also given oxycodone 5 mg as needed for breakthrough pain. Patients in the control group were prescribed ibuprofen and oxycodone 5 mg/acetaminophen 325 mg as needed for pain. The primary outcome measure was pain. Secondary outcomes were nausea, itching, and daily oxycodone use. Patients were asked to quantify their average pain at rest, nausea, and itching on an 11-point verbal scale (from 0 to 10). These data were recorded for 6 days during daily telephone contacts with patients after hospital discharge.

RESULTS

Cumulative results for 6 days showed significantly lower values in the intervention group compared with the control group for pain (median [interquartile range], 28 [14-35] vs 35 [28-41], respectively; P = .009) and oxycodone use (median [interquartile range] number of tablets, 0 [0-2] vs 8 [1.25-16], respectively; P < .001). Based on these data, the upper tolerance limits for the number of oxycodone tablets required by 90% of patients in the intervention and control groups were 8 tablets and 30 tablets, respectively. Cumulative results for nausea and itching were also significantly lower for the intervention group. Most patients in the intervention group used no opioids during recovery.

CONCLUSION

Simultaneous dosing of 3 nonopioid analgesics resulted in reduced postoperative pain and markedly lower opioid use.

REGISTRATION

NCT04015908 (ClinicalTrials.gov identifier).

Advances in the clinical application of oxycodone in the perioperative period

To review the research progress of pure opioid receptor agonist oxycodone. The research progress of oxycodone in terms of pharmacokinetics, pharmacodynamics, adverse reactions, clinical application, combined medication and new progress in clinical application was summarized by referring to the literature. Oxycodone is a semi-synthetic thebaine derivative of opioid alkaloids, and is a pure opioid μ and κ receptor agonist. The main action sites are the central nervous system and visceral smooth muscle. Due to its advantages of low adverse reactions, good analgesic effects, and a wide range of safe doses, the drug has been widely used in the control of acute and chronic postoperative pain, as well as malignant and non-malignant pain. Since the end of the 20^th century, researchers have begun to formulate antipyretic analgesics, opioid receptor agonists, opioid receptor antagonists, dopamine receptor antagonists and other drugs with oxycodone in different proportions to enhance the analgesic effect. At the same time, it can reduce the dosage of oxycodone and reduce its adverse reactions, so as to achieve the purpose of limiting opioid abuse. With the continuous research on the efficacy and safety of oxycodone in the perioperative period at home and abroad, oxycodone has become the only dual-opioid potent analgesic that can be used in clinical work.

The Opioid Analgesic Reduction Study (OARS)-a comparison of opioid vs. non-opioid combination analgesics for management of post-surgical pain: a double-blind randomized clinical trial

Background

Everyday people die unnecessarily from opioid overdose-related addiction. Dentists are among the leading prescribers of opioid analgesics. Opioid-seeking behaviors have been linked to receipt of initial opioid prescriptions following the common dental procedure of third molar extraction. With each opioid prescription, a patient’s risk for opioid misuse or abuse increases. With an estimated 56 million tablets of 5 mg hydrocodone annually prescribed after third molar extractions in the USA, 3.5 million young adults may be unnecessarily exposed to opioids by dentists who are inadvertently increasing their patient’s risk for addiction.

Methods

A double-blind, stratified randomized, multi-center clinical trial has been designed to evaluate whether a combination of over-the-counter non-opioid-containing analgesics is not inferior to the most prescribed opioid analgesic. The impacted 3rd molar extraction model is being used due to the predictable severity of the post-operative pain and generalizability of results. Within each site/clinic and gender type (male/female), patients are randomized to receive either OPIOID (hydrocodone/acetaminophen 5/300 mg) or NON-OPIOID (ibuprofen/acetaminophen 400/500 mg). Outcome data include pain levels, adverse events, overall patient satisfaction, ability to sleep, and ability to perform daily functions. To develop clinical guidelines and a clinical decision-making tool, pain management, extraction difficulty, and the number of tablets taken are being collected, enabling an experimental decision-making tool to be developed.

Discussion

The proposed methods address the shortcomings of other analgesic studies. Although prior studies have tested short-term effects of single doses of pain medications, patients and their dentists are interested in managing pain for the entire post-operative period, not just the first 12 h. After surgery, patients expect to be able to perform normal daily functions without feeling nauseous or dizzy and they desire a restful sleep at night. Parents of young people are concerned with the risks of opioid use and misuse, related either to treatments received or to subsequent use of leftover pills. Upon successful completion of this clinical trial, dentists, patients, and their families will be better able to make informed decisions regarding post-operative pain management.

Trial registration

ClinicalTrials.govNCT04452344. Registered on June 20, 2020

Research approaches for evaluating opioid sparing in clinical trials of acute and chronic pain treatments: Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials recommendations

ABSTRACT

Randomized clinical trials have demonstrated the efficacy of opioid analgesics for the treatment of acute and chronic pain conditions, and for some patients, these medications may be the only effective treatment available. Unfortunately, opioid analgesics are also associated with major risks (eg, opioid use disorder) and adverse outcomes (eg, respiratory depression and falls). The risks and adverse outcomes associated with opioid analgesics have prompted efforts to reduce their use in the treatment of both acute and chronic pain. This article presents Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) consensus recommendations for the design of opioid-sparing clinical trials. The recommendations presented in this article are based on the following definition of an opioid-sparing intervention: any intervention that (1) prevents the initiation of treatment with opioid analgesics, (2) decreases the duration of such treatment, (3) reduces the total dosages of opioids that are prescribed for or used by patients, or (4) reduces opioid-related adverse outcomes (without increasing opioid dosages), all without causing an unacceptable increase in pain. These recommendations are based on the results of a background review, presentations and discussions at an IMMPACT consensus meeting, and iterative drafts of this article modified to accommodate input from the co-authors. We discuss opioid sparing definitions, study objectives, outcome measures, the assessment of opioid-related adverse events, incorporation of adequate pain control in trial design, interpretation of research findings, and future research priorities to inform opioid-sparing trial methods. The considerations and recommendations presented in this article are meant to help guide the design, conduct, analysis, and interpretation of future trials.

Oxycodone-paracetamol tablet exhibits increased analgesic efficacy for acute postoperative pain, higher satisfaction and comparable safety profiles compared with celecoxib in patients underwent arthroscopic knee surgery

This randomized, controlled study compared the efficacy and safety between oxycodone-paracetamol tablet and celecoxib for postoperative analgesia in patients who underwent arthroscopic knee surgery (AKS). Totally, 232 patients scheduled to undergo AKS were enrolled and were randomly assigned to either the oxycodone-paracetamol (OPT group) or the celecoxib group (CEL group). Pain at rest/motion (based on pain visual analog scale (VAS) score), rescue analgesia consumption, satisfaction level and adverse events were assessed after AKS. Pain VAS score at rest was decreased at 6 h, 12 h post-AKS in the OPT group compared with the CEL group. Similarly, pain VAS score at motion was reduced at 6 h, 12 h, 24 h post-AKS in the OPT group compared to the CEL group. Furthermore, both rescue analgesia rate (14.7% vs. 33.6%) and accumulated pethidine consumption (3.7 ± 8.9 mg vs. 14.0 ± 21.2 mg) were lower in OPT group compared with the CEL group. Patients satisfaction score was either at 24 h, 48 h in OPT group compared with the CEL group. Further subgroup analyses indicated that the effect of oxycodone-paracetamol versus (vs. celecoxib) on post-AKS management was more apparent in the elderly patients and male patients. In addition, the adverse events were well tolerable (including nausea, constipation, vomiting, drowsiness and dizziness) and were of no different between the two groups. In conclusion, oxycodone-paracetamol tablet presents increased analgesic efficacy for acute postoperative pain, with higher patient satisfaction and comparable safety profiles compared with celecoxib in patients underwent AKS.

Stereotactic Electroencephalography Is Associated With Reduced Pain and Opioid Use When Compared with Subdural Grids: A Case Series

BACKGROUND

Minimally invasive surgery (MIS) has been shown to decrease length of hospital stay and opioid use.

OBJECTIVE

To identify whether surgery for epilepsy mapping via MIS stereotactically placed electroencephalography (SEEG) electrodes decreased overall opioid use when compared with craniotomy for EEG grid placement (ECoG).

METHODS

Patients who underwent surgery for epilepsy mapping, either SEEG or ECoG, were identified through retrospective chart review from 2015 through 2018. The hospital stay was separated into specific time periods to distinguish opioid use immediately postoperatively, throughout the rest of the stay and at discharge. The total amount of opioids consumed during each period was calculated by transforming all types of opioids into their morphine equivalents (ME). Pain scores were also collected using a modification of the Clinically Aligned Pain Assessment (CAPA) scale. The 2 surgical groups were compared using appropriate statistical tests.

RESULTS

The study identified 43 patients who met the inclusion criteria: 36 underwent SEEG placement and 17 underwent craniotomy grid placement. There was a statistically significant difference in median opioid consumption per hospital stay between the ECoG and the SEEG placement groups, 307.8 vs 71.5 ME, respectively (P = .0011). There was also a significant difference in CAPA scales between the 2 groups (P = .0117).

CONCLUSION

Opioid use is significantly lower in patients who undergo MIS epilepsy mapping via SEEG compared with those who undergo the more invasive ECoG procedure. As part of efforts to decrease the overall opioid burden, these results should be considered by patients and surgeons when deciding on surgical methods.

Oxycodone/Acetaminophen: The Tailoring Combination Treatment for Specific Clinical Profile of Opioid Well-Responsive Cancer Pain

Background

International guidelines recommend moderate-to-severe cancer pain to be treated with strong opioids. However, pain management remains an unsolved matter, at least in the demanding oncology and palliative care setting. Although cancer pain consists of multiple components, which interact in complex ways where combination therapy can better intercept multiple pain characteristics, few studies have used a non-opioid/opioid association to exploit possible synergistic actions. Even the efforts of a recent approach emphasizing appropriate pain assessment and accurate classification to obtain personalized pain management have not produced a satisfactory analgesic strategy.

Objective

This analysis was intended to evaluate the effectiveness of the immediate release fixed combination of oxycodone/acetaminophen (OxyIR/Par) for the treatment of moderate-to-severe intensity background pain used alone or in combination with other strong opioids in cancer patients with breakthrough cancer pain (BTcP). This is a secondary analysis of a wider observational, prospective, multicenter study [Italian Oncologic Pain multiSetting Multicentric Survey (IOPS-MS)] performed on 179 patients treated with opioids for cancer pain who received the fixed combination of oxycodone/acetaminophen (OxyIR/Par) for the treatment of background pain (BGP).

Results

Cancer patients with breakthrough cancer pain and controlled BGP (Background Pain) were classified according to the presence of analgesic therapy with tablets of fixed combination OxyIR/Par alone (group A, n=120) or tablets of fixed combination OxyIR/Par combined with other strong opioids (group B, n=59). Clinical features of group A were different to group B: higher mean Karnofsky Performance Status Index 70.3% (95% CI=67.2–73.5; median=70, CI=60–80) vs 58.3 (95% CI=53.4–63.2; median=50, CI=45–70) (P<0.001), and mainly group A patients were treated in an ambulatory setting (55.0% group A vs 33.9% group B) (p<0.001). Both groups had managed BGP with similar mean dosages (group A: 12.0, CI=10.5–13.4; group B: 13.1, CI=11.0–15.1) and frequencies of OxyIR/Par alone for group A and in association to other opioids for group B, but Breakthrough cancer Pain (BTcP) exhibited different characteristics in the two groups, showing a lower mean intensity numerical rating scale (NRS) of 7.5 (95% CI=7.2–7.7; median=7, CI=7–8 group A) vs 7.9 (95% CI=7.6, 8.2; median= 8, CI=7–9 group B) (P=0.04) and a higher percentage of patients had a faster onset, defined as the maximum intensity reached in less than 10 minutes, 81.7% (N=98) in group A vs 59.3% (n=35) in group B (P=0.002).

Conclusion

This is the first analysis about the efficacy of an immediate-release fixed combination of OxyIR/Par in the real world for moderate-to-severe background cancer pain and breakthrough cancer pain. The oral fixed combination OxyIR/Par provided an adequate level of analgesia for moderate–severe background cancer pain, in a different cohort of cancer patients with different performance status, both in ambulatory and palliative settings. The low dosage of fixed combination OxyIR/Par was effective alone or in association with other opioids.

Opioid Prescribing Laws Are Not Associated with Short-term Declines in Prescription Opioid Distribution

OBJECTIVE

To determine whether the adoption of laws that limit opioid prescribing or dispensing is associated with changes in the volume of opioids distributed in states.

METHODS

State-level data on total prescription opioid distribution for 2015-2017 were obtained from the US Drug Enforcement Administration. We included in our analysis states that enacted an opioid prescribing law in either 2016 or 2017. We used as control states those that did not have an opioid prescribing law during the study period. To avoid confounding, we excluded from our analysis states that enacted or modified mandates to use prescription drug monitoring programs (PDMPs) during the study period. To estimate the effect of opioid prescription laws on opioid distribution, we ran ordinary least squares models with indicators for whether an opioid prescription law was in effect in a state-quarter. We included state and quarter fixed effects to control for time trends and time-invariant differences between states.

RESULTS

With the exception of methadone and buprenorphine, the amount of opioids distributed in states fell during the study period. The adoption of opioid prescribing laws was not associated with additional decreases in opioids distributed.

CONCLUSIONS

We did not detect an association between adoption of opioid prescribing laws and opioids distributed. States may instead wish to pursue evidence-based efforts to reduce opioid-related harm, with a particular focus on treatment access and harm reduction interventions.

The opioid prescribing practices of surgeons: A comprehensive review of the 2015 claims to Medicare Part D

Background

The Centers for Disease Control and Prevention have declared that the United States is amidst a continuing opioid epidemic, with drug overdose–related death tripling between 1999 and 2014. Among the 47,055 overdose-related deaths that occurred in 2014, 28,647 (60.9%) of them involved an opioid.

Methods

To determine if there are specific trends in opioid prescribing practices of specific groups of surgeons to better describe any regional or subspecialty trends that exist, the Part D Prescriber Public Use File was used to evaluate all prescription drug orders for Medicare beneficiaries with a Part D prescription drug plan for the 2015 calendar year. Only those providers with the specialty description corresponding to a surgical specialty were included in this study, using the provider's Part B claims.

Results

A total of 65,277,932 claims made to Part D by 90,253 surgeons in the 2015 service year were analyzed in this study, demonstrating statistically significant differences in the opioid prescribing practices of surgeons from different states, cities, practice settings, and subspecialties (P < .05). During this year, these surgeons' opioid medication claims cost the health care system $133,091,997.81 in drug benefits.

Conclusion

All health professionals with opiate prescribing privileges are entrusted with and responsible for the use of these medications; therefore, physicians have a crucial role in ensuring safe and effective use of this treatment option and the deterrence of its abuse. This is true in particular for surgeons given the acuity level and context of their practice.

•

A total of 47,055 overdose deaths occurred in 2014; 28,647 (60.9%) of them involved an opioid.

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Medicare Part D was queried for information on prescription drug events.

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A total of 65,277,932 claims by 90,253 surgeons in the 2015 service year were analyzed.

•

Prescribing practices differed from surgeons based on states and subspecialties.

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Opioid medication claims cost the health care system $133,091,997.81 in benefits.

Laws limiting the prescribing or dispensing of opioids for acute pain in the United States: A national systematic legal review

BACKGROUND

Opioid overdose is a continuing public health crisis. In response to an increasing recognition of the negative outcomes sometimes associated with the use of opioid analgesics, states have taken a number of steps attempting to reduce inappropriate prescribing of these medications. These include the imposition of strict legal limitations on the amount or duration that opioid analgesics may be prescribed or dispensed to patients with acute pain.

METHODS

We conducted a systematic, multi-source legal review of state laws that impose mandatory limits on the ability of medical professionals to prescribe or dispense opioids for the treatment of acute pain. We also systematically searched for and examined publicly available documents on state legislative and regulatory bodies' websites. All relevant laws were downloaded and systematically coded.

RESULTS

By the end of 2017, twenty-six states had passed laws that impose mandatory limits on the prescribing or dispensing of opioids for acute pain. The oldest of these laws became effective as early as 1989, but most are much newer: approximately 65% (17/26) were passed in 2017. There is wide variation in the characteristics of these laws.

CONCLUSION

Just over half of all states have enacted laws that restrict the prescribing or dispensing of opioids for acute pain. To date, there is no data on whether and to what extent these laws mediate opioid-related morbidity and mortality, as well as whether they are associated with negative unintended outcomes. Research into these questions is urgently needed.

Opioid Prescribing: A Retrospective Analysis of Opioid Prescription Requests in a Large, Multicenter Ambulatory Care Organization

Background: To date, Atrius Health has not assessed how often patients request additional pain medication after receiving an initial opioid for acute pain management. This assessment was requested to help justify prescribing patterns for opioids in the primary care setting. Objective: To assess the amount of requests for additional opioid prescriptions in patients who received a short-acting opioid for acute pain management. Methods: This was a retrospective chart review of a multicenter large ambulatory care organization in the Greater Boston Area. Atrius Health patients who received an initial prescription for a short-acting oral opioid indicated for acute pain management between May 1, 2016, and October 1, 2016, were included in the study. Results: The overall percentage of patients requesting additional medication for acute pain management was 13% (46/350). Of the 46 patients who requested additional medication, 15 patients received a second opioid prescription (33%, 15/46). For those patients who requested additional pain medication, there were no trends between the day supply that was prescribed and a patient receiving a second opioid prescription from a health care provider. Patients who received a 4- to 5-day supply of opioids were not more likely to call back requesting additional pain medication than patients who received a 1- to 3-day supply of opioids (odd ratio = 0.41; 95% confidence interval = 0.17-1.00). Conclusion: At Atrius Health, roughly 13% of patients are requesting additional pain medications after being prescribed a short-acting opioid for acute pain management. Other primary care and urgent care health systems may consider reducing the day supply of opioids prescribed for acute pain management.

[Acute pain therapy in orthopedics/trauma surgery]

The management of acute pain is of utmost importance in the treatment regimen of orthopedic and trauma patients. Pain perception is different for each patient and has to be individually addressed. Especially in a postoperative setting often with a very dynamic course of pain, it is optimal that the pain management is adapted to the individual course of pain. In this situation it makes sense to apply patient-controlled systems. By combining different analgesic substance classes and non-pharmaceutical therapy in the sense of a multimodal concept, the mechanisms of action complement each other and side effects can be reduced. Patient satisfaction is higher when they are actively involved in the (medicinal) pain therapy and in the decision making. This is particularly important for patient-controlled analgesia (PCA). In addition to invasive catheter administration procedures, there are also modern approaches for oral individual self-administered opioid treatment.

The grass is not always greener: a multi-institutional pilot study of marijuana use and acute pain management following traumatic injury

Background

Widespread legislative efforts to legalize marijuana have increased the prevalence of marijuana use and abuse. The effects of marijuana on pain tolerance and analgesic pain management in the acute pain setting have not been reported. Although marijuana has been shown to have antinociceptive effects and is approved for medical use to treat chronic pain, anecdotal evidence suggests marijuana users admitted with traumatic injuries experience poorer pain control than patients who do not use marijuana. We hypothesized that marijuana users would report higher pain scores and require more opioid analgesia following traumatic injury.

Methods

This retrospective pilot study included all patients involved in motor vehicle crashes, consecutively admitted to four trauma centers from 1/1/2016–4/30/2016. Marijuana status was examined as non-use and use, and was further categorized as chronic and episodic use. We performed a repeated measures mixed model to examine the association between marijuana use and a) average daily opioid consumption and b) average daily pain scores (scale 0–10). Opioid analgesics were converted to be equianalgesic to 1 mg IV hydromorphone.

Results

Marijuana use was reported in 21% (54/261), of which 30% reported chronic use (16/54). Marijuana use was reported more frequently in Colorado hospitals (23–29%) compared to the hospital in Texas (6%). Drug use with other prescription/street drugs was reported in 9% of patients. Other drug use was a significant effect modifier and results were presented after stratification by drug use. After adjustment, marijuana users who did not use other drugs consumed significantly more opioids (7.6 mg vs. 5.6 mg, p <  0.001) and reported higher pain scores (4.9 vs. 4.2, p <  0.001) than non-marijuana users. Conversely, in patients who used other drugs, there were no differences in opioid consumption (5.6 mg vs. 6.1 mg, p = 0.70) or pain scores (5.3 vs. 6.0, p = 0.07) with marijuana use compared to non-use, after adjustment. Chronic marijuana use was associated with significantly higher opioid consumption compared to episodic marijuana use in concomitant drug users (11.3 mg vs. 4.4 mg, p = 0.008) but was similar in non-drug users (p = 0.41).

Conclusion

These preliminary data suggest that marijuana use, especially chronic use, may affect pain response to injury by requiring greater use of opioid analgesia. These results were less pronounced in patients who used other drugs.

Randomized Controlled Trial of Brief Mindfulness Training and Hypnotic Suggestion for Acute Pain Relief in the Hospital Setting

BACKGROUND

Medical management of acute pain among hospital inpatients may be enhanced by mind-body interventions.

OBJECTIVE

We hypothesized that a single, scripted session of mindfulness training focused on acceptance of pain or hypnotic suggestion focused on changing pain sensations through imagery would significantly reduce acute pain intensity and unpleasantness compared to a psychoeducation pain coping control. We also hypothesized that mindfulness and suggestion would produce significant improvements in secondary outcomes including relaxation, pleasant body sensations, anxiety, and desire for opioids, compared to the control condition.

METHODS

This three-arm, parallel-group randomized controlled trial conducted at a university-based hospital examined the acute effects of 15-min psychosocial interventions (mindfulness, hypnotic suggestion, psychoeducation) on adult inpatients reporting "intolerable pain" or "inadequate pain control." Participants (N = 244) were assigned to one of three intervention conditions: mindfulness (n = 86), suggestion (n = 73), or psychoeducation (n = 85).

KEY RESULTS

Participants in the mind-body interventions reported significantly lower baseline-adjusted pain intensity post-intervention than those assigned to psychoeducation (p < 0.001, percentage pain reduction: mindfulness = 23%, suggestion = 29%, education = 9%), and lower baseline-adjusted pain unpleasantness (p < 0.001). Intervention conditions differed significantly with regard to relaxation (p < 0.001), pleasurable body sensations (p = 0.001), and desire for opioids (p = 0.015), but all three interventions were associated with a significant reduction in anxiety (p < 0.001).

CONCLUSIONS

Brief, single-session mind-body interventions delivered by hospital social workers led to clinically significant improvements in pain and related outcomes, suggesting that such interventions may be useful adjuncts to medical pain management.

TRIAL REGISTRATION

Trial Registry: ClinicalTrials.gov ; registration ID number: NCT02590029 URL: https://clinicaltrials.gov/ct2/show/NCT02590029.

A randomised controlled trial of paracetamol and ibuprofen with or without codeine or oxycodone as initial analgesia for adults with moderate pain from limb injury

OBJECTIVE

Compare pain relief from non-opioid, codeine and oxycodone analgesic regimens in adults with moderate pain from limb injury.

METHOD

Double-blind, randomised, controlled, non-inferiority trial. Three regimens of six tablets, each included 2 × 500 mg paracetamol and 2 × 200 mg ibuprofen with 2 × 100 mg thiamine (non-opioid), 2 × 30 mg codeine (codeine) or 2 × 5 mg oxycodone tablets (oxycodone).

PRIMARY OUTCOME

difference in mean visual analogue scale (VAS) change between groups at 30 min, with a limit of inferiority of 13. Secondary outcomes included mean change in VAS rating from baseline to 30 min for each group, patient satisfaction, need for additional analgesia and adverse events. Pain ratings taken at 60 and 90 min for patients still in ED are described.

RESULTS

Of 182 patients randomised, non-opioid, codeine and oxycodone numbers were 61, 62 and 59. Differences (95% CI) between groups at 30 min were as follows: non-opioid versus codeine -2.6 (-8.8 to 3.6); non-opioid versus oxycodone -2.7 (-9.3 to 3.9); codeine versus oxycodone 0.1 (-6.6 to 6.4). Mean VAS reductions for non-opioid, codeine and oxycodone were -13.5, -16.1 and -16.2 mm, respectively. Satisfaction with analgesia was reported by 77.6% (64.7-87.5), 81.0% (67.2-89.0) and 73.6% (59.7-84.7) and adverse events by 3.3% (0.4-11.3), 1.6% (0.4-8.7) and 16.9% (8.4-29.0), respectively. Mean VAS reductions at 60 and 90 min were as follows: -23.2 and -18.7 mm for non-opioid; -30.7 and -33.3 mm for codeine; and -26.1 and -31.7 mm for oxycodone.

CONCLUSION

At 30 min, analgesic effects of non-opioid, codeine and oxycodone groups were non-inferior.

Oxycodone for pain in fibromyalgia in adults

BACKGROUND

This review replaces part of an earlier review that evaluated oxycodone for both neuropathic pain and fibromyalgia, which has now been split into separate reviews for the two conditions. This review will consider pain in fibromyalgia only.Opioid drugs are commonly used to treat fibromyalgia, but they may not be beneficial for people with this condition. Most reviews have examined all opioids together. This review sought evidence specifically for oxycodone, at any dose, and by any route of administration.

OBJECTIVES

To assess the analgesic efficacy and adverse events of oxycodone for treating pain in fibromyalgia in adults.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and EMBASE for randomised controlled trials from inception to 25 July 2016. We also searched the reference lists of retrieved studies and reviews, and searched online clinical trial registries.

SELECTION CRITERIA

We planned to include randomised, double-blind trials of eight weeks' duration or longer, comparing oxycodone (alone or in fixed-dose combination with naloxone) with placebo or another active treatment. We did not include observational studies.

DATA COLLECTION AND ANALYSIS

The plan was for two independent review authors to extract data and assess trial quality and potential bias. Where pooled analysis was possible, we planned to use dichotomous data to calculate risk ratio and numbers needed to treat for one additional event, using standard methods.

MAIN RESULTS

No study satisfied the inclusion criteria. Effects of interventions were not assessed as there were no included studies. We have only very low quality evidence and are very uncertain about estimates of benefit and harm.

AUTHORS' CONCLUSIONS

There is no randomised trial evidence to support or refute the suggestion that oxycodone, alone or in combination with naloxone, reduces pain in fibromyalgia.

Oxycodone for neuropathic pain in adults

BACKGROUND

This is an update of an earlier review that considered both neuropathic pain and fibromyalgia (Issue 6, 2014), which has now been split into separate reviews for the two conditions. This review considers neuropathic pain only.Opioid drugs, including oxycodone, are commonly used to treat neuropathic pain, and are considered effective by some professionals. Most reviews have examined all opioids together. This review sought evidence specifically for oxycodone, at any dose, and by any route of administration. Separate reviews consider other opioids.

OBJECTIVES

To assess the analgesic efficacy and adverse events of oxycodone for chronic neuropathic pain in adults.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and EMBASE from inception to 6 November 2013 for the original review and from January 2013 to 21 December 2015 for this update. We also searched the reference lists of retrieved studies and reviews, and two online clinical trial registries. This update differs from the earlier review in that we have included studies using oxycodone in combination with naloxone, and oxycodone used as add-on treatment to stable, but inadequate, treatment with another class of drug.

SELECTION CRITERIA

We included randomised, double-blind studies of two weeks' duration or longer, comparing any dose or formulation of oxycodone with placebo or another active treatment in chronic neuropathic pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched for studies, extracted efficacy and adverse event data, and examined issues of study quality and potential bias. Where pooled analysis was possible, we used dichotomous data to calculate risk ratio and numbers needed to treat for one additional event, using standard methods.We assessed the evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation) and created a 'Summary of findings' table.

MAIN RESULTS

The updated searches identified one additional published study, and one clinical trial registry report. We included five studies reporting on 687 participants; 637 had painful diabetic neuropathy and 50 had postherpetic neuralgia. Two studies used a cross-over design and three used a parallel group design; all studies used a placebo comparator, although one study used an active placebo (benztropine). Modified-release oxycodone (oxycodone MR) was titrated to effect and tolerability. One study used a fixed dose combination of oxycodone MR and naloxone. Two studies added oxycodone therapy to ongoing, stable treatment with either pregabalin or gabapentin. All studies had one or more sources of potential major bias.No study reported the proportion of participants experiencing 'substantial benefit' (at least 50% pain relief or who were very much improved). Three studies (537 participants) in painful diabetic neuropathy reported outcomes equivalent to 'moderate benefit' (at least 30% pain relief or who were much or very much improved), which was experienced by 44% of participants with oxycodone and 27% with placebo (number needed to treat for one additional beneficial outcome (NNT) 5.7).All studies reported group mean pain scores at the end of treatment. Three studies reported a greater pain intensity reduction and better patient satisfaction with oxycodone MR alone than with placebo. There was a similar result in the study adding oxycodone MR to stable, ongoing gabapentin, but adding oxycodone MR plus naloxone to stable, ongoing pregabalin did not show any additional effect.More participants experienced adverse events with oxycodone MR alone (86%) than with placebo (63%); the number needed to treat for an additional harmful outcome (NNH) was 4.3. Serious adverse events (oxycodone 3.4%, placebo 7.0%) and adverse event withdrawals (oxycodone 11%, placebo 6.4%) were not significantly different between groups. Withdrawals due to lack of efficacy were less frequent with oxycodone MR (1.1%) than placebo (11%), with a number needed to treat to prevent one withdrawal of 10. The add-on studies reported similar results.We downgraded the quality of the evidence to very low for all outcomes, due to limitations in the study methods, heterogeneity in the pain condition and study methods, and sparse data.

AUTHORS' CONCLUSIONS

There was only very low quality evidence that oxycodone (as oxycodone MR) is of value in the treatment of painful diabetic neuropathy or postherpetic neuralgia. There was no evidence for other neuropathic pain conditions. Adverse events typical of opioids appeared to be common.

[Perioperative pain therapy in orthopedics]

A sufficient pain management forms the foundation for a successful operative treatment of orthopedic patients. Clinical guideline standards must be provided to ensure safe and immediate pain therapy. Training in these guidelines should be held for clinical personnel on a regular basis. The visual analog scale (VAS) and the numerical rating scale (NRS) are valid instruments used for assessment of pain intensity. A sufficient pain management includes basic analgesics, analgesics on demand as well as special features, such as regional nerve blocks and patient-controlled anesthesia (PCA). The basic analgesics are primarily the groups of classical non-steroidal anti-inflammatory drugs (NSAID) and cyclooxygenase 2 (COX-2) inhibitors as well as stand by analgesics, such as metamizole. If there is further need for pain therapy, medium strong and strong opioids can be used but adverse events must be taken into consideration.

Non-prescription (OTC) oral analgesics for acute pain - an overview of Cochrane reviews

BACKGROUND

Non-prescription (over-the-counter, or OTC) analgesics (painkillers) are used frequently. They are available in various brands, package sizes, formulations, and dose. They can be used for a range of different types of pain, but this overview reports on how well they work for acute pain (pain of short duration, usually with rapid onset). Thirty-nine Cochrane reviews of randomised trials have examined the analgesic efficacy of individual drug interventions in acute postoperative pain.

OBJECTIVES

To examine published Cochrane reviews for information about the efficacy of pain medicines available without prescription using data from acute postoperative pain.

METHODS

We identified OTC analgesics available in the UK, Australia, Canada, and the USA by examining online pharmacy websites. We also included some analgesics (diclofenac potassium, dexketoprofen, dipyrone) of importance in parts of the world, but not currently available in these jurisdictions.We identified systematic reviews by searching the Cochrane Database of Systematic Reviews (CDSR) on The Cochrane Library through a simple search strategy. All reviews were overseen by a single review group, had a standard title, and had as their primary outcome numbers of participants with at least 50% pain relief over four to six hours compared with placebo. From individual reviews we extracted the number needed to treat for an additional beneficial outcome (NNT) for this outcome for each drug/dose combination, and also calculated the success rate to achieve at least 50% of maximum pain relief. We also examined the number of participants experiencing any adverse event, and whether the incidence was different from placebo.

MAIN RESULTS

We found information on 21 different OTC analgesic drugs, doses, and formulations, using information from 10 Cochrane reviews, supplemented by information from one non-Cochrane review with additional information on ibuprofen formulations (high quality evidence). The lowest (best) NNT values were for combinations of ibuprofen plus paracetamol, with NNT values below 2. Analgesics with values close to 2 included fast acting formulations of ibuprofen 200 mg and 400 mg, ibuprofen 200 mg plus caffeine 100 mg, and diclofenac potassium 50 mg. Combinations of ibuprofen plus paracetamol had success rates of almost 70%, with dipyrone 500 mg, fast acting ibuprofen formulations 200 mg and 400 mg, ibuprofen 200 mg plus caffeine 100 mg, and diclofenac potassium 50 mg having success rates above 50%. Paracetamol and aspirin at various doses had NNT values of 3 or above, and success rates of 11% to 43%. We found no information on many of the commonly available low dose codeine combinations.The proportion of participants experiencing an adverse event were generally not different from placebo, except for aspirin 1000 mg and (barely) ibuprofen 200 mg plus caffeine 100 mg. For ibuprofen plus paracetamol, adverse event rates were lower than with placebo.

AUTHORS' CONCLUSIONS

There is a body of reliable evidence about the efficacy of some of the most commonly available drugs and doses widely available without prescription. The postoperative pain model is predominantly pain after third molar extraction, which is used as the industry model for everyday pain. The proportion of people with acute pain who get good pain relief with any of them ranges from around 70% at best to less than 20% at worst; low doses of some drugs in fast acting formulations were among the best. Adverse events were generally no different from placebo. Consumers can make an informed choice based on this knowledge, together with availability and price. Headache and migraine were not included in this overview.

Adverse events associated with single dose oral analgesics for acute postoperative pain in adults - an overview of Cochrane reviews

BACKGROUND

This is an update of a Cochrane overview published in Issue 9, 2011; that overview considered both efficacy and adverse events. This overview considers adverse events, with efficacy dealt with in a separate overview.Thirty-nine Cochrane reviews of randomised trials have examined the adverse events associated with individual drug interventions in acute postoperative pain. This overview brings together the results of those individual reviews.

OBJECTIVES

To provide an overview of adverse event rates associated with single-dose oral analgesics, compared with placebo, for acute postoperative pain in adults.

METHODS

We identified systematic reviews in The Cochrane Database of Systematic Reviews on The Cochrane Library through a simple search strategy. All reviews were overseen by a single review group. We extracted information related to participants experiencing any adverse event, and reports of serious adverse events, and deaths from the individual reviews.

MAIN RESULTS

Information was available from 39 Cochrane reviews for 41 different analgesics or analgesic combinations (51 drug/dose/formulations) tested in single oral doses in participants with moderate or severe postoperative pain. This involved around 350 unique studies involving about 35,000 participants. Most studies involved younger participants with pain following removal of molar teeth.For most nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol, and combinations not containing opioids, there were few examples where participants experienced significantly more or fewer adverse events than with placebo. For aspirin 1000 mg and diflunisal 1000 mg, opioids, or fixed-dose combination drugs containing opioids, participants typically experienced significantly more adverse events than with placebo. Studies of combinations of ibuprofen and paracetamol reported significantly fewer adverse events.Serious adverse events were rare, occurring a rate of about 1 in 3200 participants.Most reviews did not report specific adverse events.

AUTHORS' CONCLUSIONS

Despite ongoing problems with the measurement, recording, and reporting of adverse events in clinical trials and in systematic reviews, the large amount of information available for single oral doses of analgesics provides evidence that adverse events rates are generally similar with active drug and placebo in these circumstances, except at higher doses of some drugs, and in combinations including opioids.

Single dose oral analgesics for acute postoperative pain in adults - an overview of Cochrane reviews

BACKGROUND

This is an updated version of the original Cochrane overview published in Issue 9, 2011. That overview considered both efficacy and adverse events, but adverse events are now dealt with in a separate overview.Thirty-nine Cochrane reviews of randomised trials have examined the analgesic efficacy of individual drug interventions in acute postoperative pain. This overview brings together the results of those individual reviews and assesses the reliability of available data.

OBJECTIVES

To summarise the efficacy of pharmaceutical interventions for acute pain in adults with at least moderate pain following surgery who have been given a single dose of oral analgesic.

METHODS

We identified systematic reviews in the Cochrane Database of Systematic Reviews in The Cochrane Library through a simple search strategy. All reviews were overseen by a single review group, had a standard title, and had as their primary outcome the number of participants with at least 50% pain relief over four to six hours compared with placebo. For individual reviews, we extracted the number needed to treat for an additional beneficial outcome (NNT) for this outcome for each drug/dose combination, and also the percentage of participants achieving at least 50% maximum pain relief, the mean of mean or median time to remedication, and the percentage of participants remedicating by six, eight, 12, or 24 hours. Where there was adequate information for pairs of drug and dose (at least 200 participants, in at least two studies), we defined the addition of four comparisons of typical size (400 participants in total) with zero effect as making the result potentially subject to publication bias and therefore unreliable.

MAIN RESULTS

The overview included 39 separate Cochrane Reviews with 41 analyses of single dose oral analgesics tested in acute postoperative pain models, with results from about 50,000 participants in approximately 460 individual studies. The individual reviews included only high-quality trials of standardised design, methods, and efficacy outcome reporting. No statistical comparison was undertaken.Reliable results (high quality information) were obtained for 53 pairs of drug and dose in painful postsurgical conditions; these included various fixed dose combinations, and fast acting formulations of some analgesics. NNTs varied from about 1.5 to 20 for at least 50% maximum pain relief over four to six hours compared with placebo. The proportion of participants achieving this level of benefit varied from about 30% to over 70%, and the time to remedication varied from two hours (placebo) to over 20 hours. Good (low) NNTs were obtained with ibuprofen 200 mg plus paracetamol (acetaminophen) 500 mg (NNT compared with placebo 1.6; 95% confidence interval 1.5 to 1.8), ibuprofen fast acting 200 mg (2.1; 1.9 to 2.3); ibuprofen 200 mg plus caffeine 100 mg (2.1; 1.9 to 3.1), diclofenac potassium 50 mg (2.1; 1.9 to 2.5), and etoricoxib 120 mg (1.8; 1.7 to 2.0). For comparison, ibuprofen acid 400 mg had an NNT of 2.5 (2.4 to 2.6). Not all participants had good pain relief and, for many pairs of drug and dose, 50% or more did not achieve at least 50% maximum pain relief over four to six hours.Long duration of action (eight hours or greater) was found for etoricoxib 120 mg, diflunisal 500 mg, paracetamol 650 mg plus oxycodone 10 mg, naproxen 500/550 mg, celecoxib 400 mg, and ibuprofen 400 mg plus paracetamol 1000 mg.There was no evidence of analgesic effect for aceclofenac 150 mg, aspirin 500 mg, and oxycodone 5 mg (low quality evidence). No trial data were available in reviews of acemetacin, meloxicam, nabumetone, nefopam, sulindac, tenoxicam, and tiaprofenic acid. Inadequate amounts of data were available for nine drugs and doses, and data potentially susceptible to publication bias for 13 drugs and doses (very low quality evidence).

AUTHORS' CONCLUSIONS

There is a wealth of reliable evidence on the analgesic efficacy of single dose oral analgesics. Fast acting formulations and fixed dose combinations of analgesics can produce good and often long-lasting analgesia at relatively low doses. There is also important information on drugs for which there are no data, inadequate data, or where results are unreliable due to susceptibility to publication bias. This should inform choices by professionals and consumers.

Impact of a Mandatory Prescription Drug Monitoring Program on Prescription of Opioid Analgesics by Dentists

Prescription Drug Monitoring Programs (PDMP) are statewide databases that collect data on prescription of controlled substances. New York State mandates prescribers to consult the PDMP registry before prescribing a controlled substance such as opioid analgesics. The effect of mandatory PDMP on opioid drug prescriptions by dentists is not known. This study investigates the impact of mandatory PDMP on frequency and quantity of opioid prescriptions by dentists in a dental urgent care center. Based on the sample size estimate, we collected patient records of a 3-month period before and two consecutive 3-month periods after the mandatory PDMP implementation and analyzed the data on number of visits, treatment types and drug prescriptions using Chi-square tests. For patients who were prescribed pain medications, 452 (30.6%), 190 (14.1%), and 140 (9.6%) received opioid analgesics in the three study periods respectively, signifying a statistically significant reduction in the number of opioid prescriptions after implementation of the mandatory PDMP (p<0.05). Total numbers of prescribed opioid pills in a 3-month period decreased from 5096 to 1120, signifying a 78% reduction in absolute quantity. Prescriptions for non-opioid analgesics acetaminophen increased during the same periods (p<0.05). We conclude that the mandatory PDMP significantly affected the prescription pattern for pain medications by dentists. Such change in prescription pattern represents a shift towards the evidence-based prescription practices for acute postoperative pain.

Comparative Analgesic Efficacy of Oxycodone/Acetaminophen vs Codeine/Acetaminophen for Short-Term Pain Management Following ED Discharge

OBJECTIVE

To test the hypothesis that oxycodone/acetaminophen provides analgesia superior to codeine/acetaminophen following emergency department (ED) discharge.

DESIGN

Prospective, randomized, double-blind, trial.

SETTING

Adult inner city ED.

SUBJECTS

ED patients with acute extremity pain who were discharged home.

METHODS

Patients randomized to oxycodone/acetaminophen (5 mg/325 mg) or codeine/acetaminophen (30 mg/300 mg). The primary outcome, obtained via telephone one day after ED discharge, was the between-group difference in improvement in numerical rating scale (NRS) pain scores over a 2-hour period following the most recent ingestion of study drug. Secondary outcomes included proportion of patients with >50% pain reduction, side-effect profile, and patient satisfaction.

RESULTS

Two hundred and forty patients were enrolled. Mean baseline NRS scores were 7.9 in both groups. Mean decrease over 2 hours was 4.5 NRS units in the oxycodone/acetaminophen group vs 4.2 NRS units in the codeine/acetaminophen group, for a clinically and statistically nonsignificant difference of 0.2 NRS units (95% CI -0.4-0.9 NRS units). Similarly, 66% vs 61% achieved >50% pain relief for a nonsignificant difference of 5% (95% CI -8% to 17%). Side-effect profile and patient satisfaction were similar.

CONCLUSION

Our hypothesis that oxycodone/acetaminophen provides analgesia superior to codeine/acetaminophen was rejected. Although pain within each group was reduced by more than half, the between-group difference was not significant. Pending independent validation, these unexpected findings suggest that codeine/acetaminophen, a Schedule III agent, may be a clinically reasonable outpatient opioid alternative to oxycodone/acetaminophen, a more tightly restricted Schedule II agent thought to be more prone to misuse.

Dexketoprofen/tramadol: randomised double-blind trial and confirmation of empirical theory of combination analgesics in acute pain

Background

Combination analgesics are effective in acute pain, and a theoretical framework predicts efficacy for combinations. The combination of dexketoprofen and tramadol is untested, but predicted to be highly effective.

Methods

This was a randomised, double-blind, double-dummy, parallel-group, placebo-controlled, single-dose trial in patients with moderate or severe pain following third molar extraction. There were ten treatment arms, including dexketoprofen trometamol (12.5 mg and 25 mg) and tramadol hydrochloride (37.5 mg and 75 mg), given as four different fixed combinations and single components, with ibuprofen 400 mg as active control as well as a placebo control. The study objective was to evaluate the superior analgesic efficacy and safety of each combination and each single agent versus placebo. The primary outcome was the proportion of patients with at least 50 % max TOTPAR over six hours.

Results

606 patients were randomised and provided at least one post-dose assessment. All combinations were significantly better than placebo. The highest percentage of responders (72 %) was achieved in the dexketoprofen trometamol 25 mg plus tramadol hydrochloride 75 mg group (NNT 1.6, 95 % confidence interval 1.3 to 2.1). Addition of tramadol to dexketoprofen resulted in greater peak pain relief and greater pain relief over the longer term, particularly at times longer than six hours (median duration of 8.1 h). Adverse events were unremarkable.

Conclusions

Dexketoprofen trometamol 25 mg combined with tramadol hydrochloride 75 mg provided good analgesia with rapid onset and long duration in a model of moderate to severe pain. The results of the dose finding study are consistent with pre-trial calculations based on empirical formulae.

Trial registration

EudraCT (2010-022798-32); Clinicaltrials.gov (NCT01307020).

Electronic supplementary material

The online version of this article (doi:10.1186/s10194-015-0541-5) contains supplementary material, which is available to authorized users.

The Potential Role of an Extended-Release, Abuse-Deterrent Oxycodone/Acetaminophen Fixed-Dose Combination Product for the Treatment of Acute Pain

Acute pain, prevalent as part of postoperative and traumatic pain, is often sub-optimally or inadequately treated. Fixed-dose combination analgesic products that combine a reduced amount of opioid with a nonopioid analgesic such as acetaminophen (paracetamol) in a single tablet offer potential pharmacodynamic and/or pharmacokinetic benefits, and may also result in an opioid-sparing effect. A new analgesic product (XARTEMIS™ XR, Mallinckrodt Brand Pharmaceuticals, Dublin, Ireland) combines oxycodone (7.5 mg) with acetaminophen (325 mg) in an immediate-release/extended-release (ER) formulation that is indicated for the treatment of acute pain. The ER formulation of this product provides stable serum drug concentrations that in this case lasts 12 h. Oxycodone/acetaminophen is a drug combination that offers safe and effective pain relief in a variety of acute pain syndromes such as postoperative pain. The combination formulation allows a smaller amount of oxycodone per tablet and the biphasic-layered matrix of the pill for ER may present obstacles to potential abusers. No opioid is totally abuse resistant, but the lower opioid content and tamper-resistant formulation of this product might discourage abuse. Clinicians must still be mindful of the acetaminophen part of this product in the patient’s overall daily intake (in light of acetaminophen hepatotoxicity). The new product appears to provide an important new choice in the armamentarium against acute pain.

Oral oxycodone for pain after caesarean section: A randomized comparison with nurse-administered IV morphine in a pragmatic study

Background and aims The present randomized open label parallel group study was conducted to evaluate if an oral oxycodone (OXY) regimen can be at least equally effective and as safe for postoperative analgesia after caesarean section (CS) as a standard of care program using nurse-administered intravenous morphine (IVM), followed by oral codeine. Methods Eighty women (40 + 40) were scheduled for elective CS under spinal anaesthesia. All patients received postoperative multimodal analgesic therapy, including ibuprofen and paracetamol. The OXY group got standardized extended release and short acting oral treatment (and in a few cases intravenous OXY) as needed and the other group received current standard of care, IVM as needed for 24 h, followed by codeine. Opioid treatment lasted maximum five days. Outcome measures were pain intensity (numerical rating scale, NRS), opioid requirements, duration of administering opioids and safety for mother and newborn. All opioids in the study were expressed in OXY equivalents, using a conversion table. As the bioavailability of each opioid has a certain extent of interindividual bioavailability this conversion represents an approximation. The possible influence of opioids on the newborns was evaluated by the Neurological Adaptive Capacity Score at birth and at 24 and 48 h. Results During the first 24 h, there were no differences between treatments in opioid requirements or mean pain intensity at rest but pain intensity when asking for rescue medication was lower in the OXY than in the IVM group (mean ± SD; 5.41 ± 6.42 vs. 6.42 ± 1.61; p = 0.027). Provoked pain (uterus palpation) during the first 6h was also less in the OXY group (3.26 ± 2.13 vs. 4.60 ± 2.10; p = 0.007). During the 25-48 h period postoperatively, patients on OXY reported significantly lower pain intensity at rest (2.9 ± 1.9 vs. 3.8 ± 1.8; p = 0.039) and consumed less opioids (OXY equivalents; mg) (31.5 ± 9.6 vs. 38.2 ± 38.2; p = 0.001) than those on IVM/codeine. The total amount of opioids 0-5 days postoperatively was significantly lower in the OXY than in the IVM/codeine group (108.7 ± 37.6 vs. 138.2 ± 45.1; p = 0.002). Duration of administering opioids was significantly shorter in the OXY group. Time to first spontaneous bowel movement was shorter in the OXY group compared with the IVM/codeine group. No serious adverse events were recorded in the mothers but the total number of common opioid adverse effects was higher among women on IVM/codeine than among those receiving OXY (15 vs. 3; p = 0.007). No adverse outcomes in the newborns related to treatment were observed in either group. Conclusions In a multimodal protocol for postoperative analgesia after CS better pain control and lower opioid intake was observed in patients receiving oral OXY as compared to those on IVM/codeine. No safety risks for mother and child were identified with either protocol. Implications Our findings support the view that use of oral OXY is a simple, effective and time saving treatment for postoperative pain after CS.

Controlled-release oxycodone versus naproxen at home after ambulatory surgery: a randomized controlled trial

Background

Strong opioids in the home setting after ambulatory surgery have rarely been studied for fear of hazardous adverse effects such as respiratory depression.

Objectives

We compared the efficacy of paracetamol/controlled-release (CR) oxycodone and paracetamol/naproxen for treatment of acute postoperative pain at home after ambulatory surgery. Secondary outcomes were adverse effects of study medication, treatment satisfaction, and postoperative analgesic compliance.

Methods

Patients undergoing ambulatory knee arthroscopy or inguinal hernia repair surgery (n = 105) were randomized into 3 groups: Group1 paracetamol/naproxen (n = 35), Group 2 paracetamol/CR oxycodone for 24 hours (n = 35), and Group 3 paracetamol/CR oxycodone for 48 hours (n = 35). Pain intensity at movement and at rest using a visual analog scale as well as satisfaction with postoperative analgesia and side effects were recorded for up to 48 hours postoperatively. Compliance with study medication was also assessed.

Results

For pain at movement and at rest, no significant differences were found between the paracetamol/naproxen group and either the paracetamol/CR oxycodone for 24 hours group (β = 2.6 [4.9]; P = 0.597) or the paracetamol/CR oxycodone for 48 hours (β = –1.7 [5.1]; P = 0.736). No major adverse effects of study medication were registered and satisfaction with postoperative pain treatment was high in all groups. Compliance was comparable across the groups. Despite clear instructions, 8 patients with the lowest pain scores did not use any of the prescribed pain medication.

Conclusions

Paracetamol/CR oxycodone and paracetamol/naproxen are equally effective in treatment of acute postoperative pain at home after ambulatory surgery with comparable patient satisfaction level. We suggest paracetamol/CR oxycodone to be a valuable alternative for the current paracetamol/naproxen gold standard, particularly in patients with a contraindication for nonsteroidal anti-inflammatory drugs. ClinicalTrials.gov identifier: NCT02152592.

Pharmacokinetics and bioavailability of oxycodone and acetaminophen following single-dose administration of MNK-795, a dual-layer biphasic IR/ER combination formulation, under fed and fasted conditions

BACKGROUND

XARTEMIS™ XR (formerly MNK-795) is a combination oxycodone (OC) and acetaminophen (APAP) analgesic with both immediate-release and extended-release (ER) components (ER OC/APAP). The tablets are designed with gastric-retentive ER oral delivery technology that releases the ER component at a controlled rate in the upper gastrointestinal tract. Because consumption of food has demonstrated an impact on the pharmacokinetics (PK) of some marketed products using gastric-retentive ER oral delivery technology, a characterization of the effects of fed (high- and low-fat diets) versus fasted conditions on the PK of ER OC/APAP was performed.

METHODS

This Phase I study used an open-label randomized single-dose three-period six-sequence crossover single-center design. Healthy adult participants (n=48) were randomized to receive two tablets of ER OC/APAP under three conditions: following a high-fat meal; following a low-fat meal; and fasted. Plasma concentration versus time data from predose throughout designated times up to 48 hours postdose was used to estimate the PK parameters of oxycodone and APAP.

RESULTS

Thirty-one participants completed all three treatment periods. Both oxycodone and APAP were rapidly absorbed under fasted conditions. Total oxycodone and APAP exposures (area under the plasma drug concentration-time curve [AUC]) from ER OC/APAP were not significantly affected by food, and minimal changes to maximum observed plasma concentration for oxycodone and APAP were also noted. However, food marginally delayed the time to maximum observed plasma concentration of oxycodone and APAP. There was no indication that tolerability was affected by food.

CONCLUSION

The findings from this study suggest that ER OC/APAP can be administered with or without food.

Oxycodone for neuropathic pain and fibromyalgia in adults

BACKGROUND

This review is one of a series on drugs used to treat neuropathic pain and fibromyalgia. These conditions are estimated to affect 3 to 10% of adults, and are difficult to treat. Although they probably have different aetiologies, neuropathic pain and fibromyalgia can respond to the same therapies. There have been substantial changes in the standards of evidence considered necessary for assessment of interventions to treat chronic pain, to provide data that are more robust and clinically relevant. Oxycodone is a strong opioid agonist widely used to manage severe pain; this review assesses evidence for oxycodone using current standards of evidence designed to reduce bias.

OBJECTIVES

To assess the analgesic efficacy and adverse events of oxycodone for chronic neuropathic pain and fibromyalgia.

SEARCH METHODS

On 6 November 2013, we searched CENTRAL, MEDLINE and EMBASE databases. We reviewed the bibliographies of all included studies and of reviews, and also searched two clinical trial databases, ClinicalTrials.gov and the World Health Organisation (WHO) International Clinical Trials Registry Platform, to identify additional published or unpublished data.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) with double-blind assessment of participant outcomes following two weeks of treatment or longer (although the emphasis of the review was on studies of eight weeks or longer) that used a placebo or active comparator.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted efficacy and adverse event data, examined issues of study quality, and assessed risk of bias. We performed analysis using three tiers of evidence. First tier evidence was derived from data meeting current best standards and subject to minimal risk of bias (outcome equivalent to substantial pain intensity reduction, intention-to-treat analysis without imputation for dropouts; at least 200 participants in the comparison, eight to 12 weeks duration, parallel design), second tier from data that failed to meet one or more of these criteria and were considered at some risk of bias but with adequate numbers in the comparison, and third tier from data involving small numbers of participants that was considered very likely to be biased or used outcomes of limited clinical utility, or both.

MAIN RESULTS

We included three studies with 254 participants; 204 had painful diabetic neuropathy and 50 postherpetic neuralgia. Study size ranged from 45 to 159 participants. Two studies used a cross-over design and one a parallel group design; study duration was four or six weeks. Controlled release oxycodone (oxycodone CR) was used in all three studies, with doses titrated up to a maximum of between 60 and 120 mg daily; mean doses achieved ranged between 37 and 45 mg daily. All studies used a placebo comparator, although in one study, an active placebo (benztropine) was used. All studies had one or more sources of potential major bias.No study reported the proportion of participants experiencing at least 50% pain relief or who were very much improved, while one reported the proportion with at least 30% pain relief, two reported at least moderate pain relief, and one reported the number of participants who considered treatment to be moderately effective. No study provided first or second tier evidence for an efficacy outcome. Third tier evidence indicated greater pain intensity reduction and better patient satisfaction with oxycodone than with placebo in all three studies, but such evidence was derived mainly from group mean data, with last observation carried forward (LOCF) imputation or completer analysis, in small studies lasting less than eight weeks (very low quality evidence).Adverse events were more common with oxycodone CR than with placebo. At least one adverse event was experienced by 86% of participants taking oxycodone CR and 63% taking placebo, and the number needed to treat for an additional harmful effect (NNH) was 4.3. The effect of oxycodone on serious adverse events reported was uncertain in comparison with placebo (oxycodone 3.4% versus placebo: 7.0%; RR 0.48 (95% confidence interval (CI) 0.18 to 1.23; very low quality evidence); one death was reported with oxycodone CR, but was not attributed to treatment. Adverse event withdrawals did not differ significantly between groups, occurring in 11% of participants with oxycodone CR and 6.4% with placebo (RR 1.69 (0.83 to 3.43); very low quality evidence). Withdrawals due to lack of efficacy were less frequent with oxycodone CR (1.1%) than placebo (11%), with an NNT to prevent one withdrawal of 10 (RR 0.12 (0.03 to 0.45); very low quality evidence).We found no relevant studies in chronic neuropathic pain conditions other than painful diabetic neuropathy or postherpetic neuralgia, or in fibromyalgia.

AUTHORS' CONCLUSIONS

No convincing, unbiased evidence suggests that oxycodone (as oxycodone CR) is of value in treating people with painful diabetic neuropathy or postherpetic neuralgia. There is no evidence at all for other neuropathic pain conditions, or for fibromyalgia. Adverse events typical of opioids appear to be common.

Oral oxycodone plus intravenous acetaminophen versus intravenous morphine sulfate in acute bone fracture pain control: a double-blind placebo-controlled randomized clinical trial

OBJECTIVES

Bone fracture is a common cause of acute pain in emergency and orthopedics departments. Targeting the multifaceted mechanisms of pain with combinations of multiple analgesics (multimodal analgesia) can increase the pain control efforts efficacy and decrease the adverse effects of each medication.

METHODS

One hundred and fifty-three patients with acute bone fracture were randomly allocated to two groups receiving intravenous morphine sulfate (74 patients) or oral oxycodone plus intravenous acetaminophen (79 patients). Pain scores and drugs' adverse effects were assessed 10, 30 and 60 min after treatment.

RESULTS

Pain scores were similar between groups before, 30 and 60 min after medication but patients in morphine sulfate group experienced less pain 10 min after medication. Eight (10.8%) patients in morphine sulfate group and 26 (32.9%) patients in acetaminophen/oxycodone group experienced nausea that was statistically significant higher (P value = 0.001). Itching was seen in 12 (15.1%) patients of acetaminophen/oxycodone group and three (4.0%) patients of patients in morphine sulfate group (P value = 0.02).

CONCLUSION

Intravenous acetaminophen plus oral oxycodone is as effective as intravenous morphine sulfate in acute pain control in emergency department but with a less desirable safety profile.

Clinical pharmacology of analgesics assessed with human experimental pain models: bridging basic and clinical research

The medical impact of pain is such that much effort is being applied to develop novel analgesic drugs directed towards new targets and to investigate the analgesic efficacy of known drugs. Ongoing research requires cost-saving tools to translate basic science knowledge into clinically effective analgesic compounds. In this review we have re-examined the prediction of clinical analgesia by human experimental pain models as a basis for model selection in phase I studies. The overall prediction of analgesic efficacy or failure of a drug correlated well between experimental and clinical settings. However, correct model selection requires more detailed information about which model predicts a particular clinical pain condition. We hypothesized that if an analgesic drug was effective in an experimental pain model and also a specific clinical pain condition, then that model might be predictive for that particular condition and should be selected for development as an analgesic for that condition. The validity of the prediction increases with an increase in the numbers of analgesic drug classes for which this agreement was shown. From available evidence, only five clinical pain conditions were correctly predicted by seven different pain models for at least three different drugs. Most of these models combine a sensitization method. The analysis also identified several models with low impact with respect to their clinical translation. Thus, the presently identified agreements and non-agreements between analgesic effects on experimental and on clinical pain may serve as a solid basis to identify complex sets of human pain models that bridge basic science with clinical pain research.

Single dose oral ibuprofen plus oxycodone for acute postoperative pain in adults

BACKGROUND

Combining two different analgesics in fixed doses in a single tablet can provide better pain relief than either drug alone in acute pain. This appears to be broadly true across a range of different drug combinations, in postoperative pain and migraine headache. Fixed-dose combinations of ibuprofen and oxycodone are available, and the drugs may be separately used in combination in some acute pain situations.

OBJECTIVES

To assess the analgesic efficacy and adverse effects of a single oral dose of ibuprofen plus oxycodone for moderate to severe postoperative pain.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, (CENTRAL), on The Cochrane Library, (Issue 4 of 12, 2013), MEDLINE (1950 to 21st May 2013), EMBASE (1974 to 21st May 2013), the Oxford Pain Database, ClinicalTrials.gov, and reference lists of articles.

SELECTION CRITERIA

Randomised, double-blind clinical trials of single dose, oral ibuprofen plus oxycodone compared with placebo or the same dose of ibuprofen alone for acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently considered trials for inclusion in the review, assessed quality, and extracted data. We used the area under the pain relief versus time curve to derive the proportion of participants prescribed ibuprofen plus oxycodone, ibuprofen alone, oxycodone alone, or placebo with at least 50% pain relief over six hours, using validated equations. We calculated relative risk (RR) and number needed to treat to benefit (NNT). We used information on use of rescue medication to calculate the proportion of participants requiring rescue medication and the weighted mean of the median time to use. We also collected information on adverse events.

MAIN RESULTS

Searches identified three studies involving 1202 participants. All examined the same dose combination. Included studies provided data from 603 participants for the comparison of ibuprofen 400 mg + oxycodone 5 mg with placebo, 717 participants for the comparison of ibuprofen 400 mg + oxycodone 5 mg with ibuprofen 400 mg alone, and 471 participants for the comparison of ibuprofen 400 mg + oxycodone 5 mg with oxycodone 5 mg alone.The proportion of participants achieving at least 50% pain relief over 6 hours was 60% with ibuprofen 400 mg + oxycodone 5 mg and 17% with placebo, giving an NNT of 2.3 (2.0 to 2.8). For ibuprofen 400 mg alone the proportion was 50%, producing no significant difference between ibuprofen 400 mg + oxycodone 5 mg and ibuprofen 400 mg alone. For oxycodone 5 mg alone the proportion was 23%, giving an NNT for ibuprofen 400 mg + oxycodone 5 mg compared with oxycodone alone of 2.9 (2.3 to 4.0).Ibuprofen + oxycodone resulted in longer times to remedication than with placebo. The median time to use of rescue medication was more than 5 hours for ibuprofen 400 mg + oxycodone 5 mg, and 2.3 hours or less with placebo. Fewer participants needed rescue medication with ibuprofen + oxycodone combination than with placebo or ibuprofen alone. The proportion was 40% with ibuprofen 400 mg + oxycodone 5 mg, 83% with placebo, 53% with ibuprofen alone, and 83% with oxycodone alone, giving NNT to prevent one patient needing rescue medication of 2.4 (2.0 to 2.9), 11 (6.1 to 56), and 2.6 (2.1 to 3.4) for comparisons of ibuprofen 400 mg + oxycodone 5 mg with placebo, ibuprofen alone, and oxycodone alone, respectively.The proportion of participants experiencing one or more adverse events was 25% with ibuprofen 400 mg + oxycodone 5 mg, 25% with placebo, 26% with ibuprofen alone, and 35% with oxycodone alone; they were not significantly different. Serious adverse events were reported only after abdominal surgery 6/169 with the combination, 1/175 with ibuprofen alone, 3/52 with oxycodone alone, and 1/60 with placebo. Withdrawals for reasons other than lack of efficacy were fewer than 5% and balanced across treatment arms.

AUTHORS' CONCLUSIONS

The combination of ibuprofen 400mg + oxycodone 5mg provided analgesia for longer than oxycodone alone, but not ibuprofen alone (at the same dose). There was also a smaller chance of needing additional analgesia over about eight hours, and with no greater chance of experiencing an adverse event.

Single dose oral ibuprofen plus paracetamol (acetaminophen) for acute postoperative pain

BACKGROUND

Combining two different analgesics in fixed doses in a single tablet can provide better pain relief than either drug alone in acute pain. This appears to be broadly true across a range of different drug combinations, in postoperative pain and migraine headache. Some combinations of ibuprofen and paracetamol are available for use without prescription in some acute pain situations.

OBJECTIVES

To assess the efficacy and adverse effects of single dose oral ibuprofen plus paracetamol for acute postoperative pain using methods that permit comparison with other analgesics evaluated in standardised trials using almost identical methods and outcomes.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 4 of 12, 2013), MEDLINE (1950 to May 21st 2013), EMBASE (1974 to May 21st 2013), the Oxford Pain Database, ClinicalTrials.gov, and reference lists of articles.

SELECTION CRITERIA

Randomised, double-blind clinical trials of single dose, oral ibuprofen plus paracetamol compared with placebo or the same dose of ibuprofen alone for acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently considered trials for inclusion in the review, assessed quality, and extracted data. We used validated equations to calculate the area under the pain relief versus time curve and derive the proportion of participants with at least 50% of maximum pain relief over six hours. We calculated relative risk (RR) and number needed to treat to benefit (NNT) for ibuprofen plus paracetamol, ibuprofen alone, or placebo. We used information on use of rescue medication to calculate the proportion of participants requiring rescue medication and the weighted mean of the median time to use. We also collected information on adverse events.

MAIN RESULTS

Searches identified three studies involving 1647 participants. Each of them examined several dose combinations. Included studies provided data from 508 participants for the comparison of ibuprofen 200 mg + paracetamol 500 mg with placebo, 543 participants for the comparison of ibuprofen 400 mg + paracetamol 1000 mg with placebo, and 359 participants for the comparison of ibuprofen 400 mg + paracetamol 1000 mg with ibuprofen 400 mg alone.The proportion of participants achieving at least 50% maximum pain relief over 6 hours was 69% with ibuprofen 200 mg + paracetamol 500 mg, 73% with ibuprofen 400 mg + paracetamol 1000 mg, and 7% with placebo, giving NNTs of 1.6 (1.5 to 1.8) and 1.5 (1.4 to 1.7) for the lower and higher doses respectively compared with placebo. For ibuprofen 400 mg alone the proportion was 52%, giving an NNT for ibuprofen 400 mg + paracetamol 1000 mg compared with ibuprofen alone of 5.4 (3.5 to 12).Ibuprofen + paracetamol at the 200/500 mg and 400/1000 mg doses resulted in longer times to remedication than placebo. The median time to use of rescue medication was 7.6 hours for ibuprofen 200 mg + paracetamol 500 mg, 8.3 hours with ibuprofen 400 mg + paracetamol 1000 mg, and 1.7 hours with placebo. Fewer participants needed rescue medication with ibuprofen + paracetamol combination than with placebo or ibuprofen alone. The proportion was 34% with ibuprofen 200 mg + paracetamol 500 mg, 25% with ibuprofen 400 mg + paracetamol 1000 mg, and 79% with placebo, giving NNTs to prevent use of rescue medication of 2.2 (1.8 to 2.9) and 1.8 (1.6 to 2.2) respectively compared with placebo. The proportion of participants using rescue medication with ibuprofen 400 mg was 48%, giving an NNT to prevent use for ibuprofen 400 mg + paracetamol 1000 mg compared with ibuprofen alone of 4.3 (3.0 to 7.7).The proportion of participants experiencing one or more adverse events was 30% with ibuprofen 200 mg + paracetamol 500 mg, 29% with ibuprofen 400 mg + paracetamol 1000 mg, and 48% with placebo, giving NNT values in favour of the combination treatment of 5.4 (3.6 to 10.5) and 5.1 (3.5 to 9.5) for the lower and higher doses respectively. No serious adverse events were reported in any of the included studies. Withdrawals for reasons other than lack of efficacy were fewer than 5% and balanced across treatment arms.

AUTHORS' CONCLUSIONS

Ibuprofen plus paracetamol combinations provided better analgesia than either drug alone (at the same dose), with a smaller chance of needing additional analgesia over about eight hours, and with a smaller chance of experiencing an adverse event.

The modern pharmacology of paracetamol: therapeutic actions, mechanism of action, metabolism, toxicity and recent pharmacological findings

Paracetamol is used worldwide for its analgesic and antipyretic actions. It has a spectrum of action similar to that of NSAIDs and resembles particularly the COX-2 selective inhibitors. Paracetamol is, on average, a weaker analgesic than NSAIDs or COX-2 selective inhibitors but is often preferred because of its better tolerance. Despite the similarities to NSAIDs, the mode of action of paracetamol has been uncertain, but it is now generally accepted that it inhibits COX-1 and COX-2 through metabolism by the peroxidase function of these isoenzymes. This results in inhibition of phenoxyl radical formation from a critical tyrosine residue essential for the cyclooxygenase activity of COX-1 and COX-2 and prostaglandin (PG) synthesis. Paracetamol shows selectivity for inhibition of the synthesis of PGs and related factors when low levels of arachidonic acid and peroxides are available but conversely, it has little activity at substantial levels of arachidonic acid and peroxides. The result is that paracetamol does not suppress the severe inflammation of rheumatoid arthritis and acute gout but does inhibit the lesser inflammation resulting from extraction of teeth and is also active in a variety of inflammatory tests in experimental animals. Paracetamol often appears to have COX-2 selectivity. The apparent COX-2 selectivity of action of paracetamol is shown by its poor anti-platelet activity and good gastrointestinal tolerance. Unlike both non-selective NSAIDs and selective COX-2 inhibitors, paracetamol inhibits other peroxidase enzymes including myeloperoxidase. Inhibition of myeloperoxidase involves paracetamol oxidation and concomitant decreased formation of halogenating oxidants (e.g. hypochlorous acid, hypobromous acid) that may be associated with multiple inflammatory pathologies including atherosclerosis and rheumatic diseases. Paracetamol may, therefore, slow the development of these diseases. Paracetamol, NSAIDs and selective COX-2 inhibitors all have central and peripheral effects. As is the case with the NSAIDs, including the selective COX-2 inhibitors, the analgesic effects of paracetamol are reduced by inhibitors of many endogenous neurotransmitter systems including serotonergic, opioid and cannabinoid systems. There is considerable debate about the hepatotoxicity of therapeutic doses of paracetamol. Much of the toxicity may result from overuse of combinations of paracetamol with opioids which are widely used, particularly in USA.

A comparison of oxycodone prolonged-release vs. oxycodone + naloxone prolonged-release after laparoscopic hysterectomy

BACKGROUND

Targiniq®, an oxycodone prolonged-release (PR) formulation combined with the opioid antagonist naloxone PR, aims to prevent opioid-induced constipation without impairing the analgesic efficacy. This has been confirmed during prolonged use in chronic pain or cancer patients. The purpose of our study was to compare clinical effects of oxycodone PR with oxycodone PR + naloxone PR for short-term post-operative pain management.

METHODS

This randomised, double-blind, prospective study included 85 women undergoing laparoscopic hysterectomy. The two groups received either oxycodone PR 10 mg or oxycodone PR 10 mg + naloxone PR 5 mg as pre-medication and twice daily for 3 days. As rescue analgesic, the patients received oxycodone intravenous during the first 24 h post-operatively and oxycodone tablets in the 24-72-h period. Constipation, other side effects, pain and satisfaction were registered during the first 7 post-operative days.

RESULTS

Demographic, pre- and perioperative variables and the use of rescue analgesics were similar in the groups. There were no significant differences in variables related to constipation. In the oxycodone PR + naloxone PR group, 25% had no defecation during the first 72 h post-operatively, compared with 20% in the oxycodone PR group (mean 1.2 ± 1.1 vs. 2.1 ± 2.4 defecations). Other opioid-induced effects and side effects showed no significant differences. Only 7% were dissatisfied with their oral pain treatment.

CONCLUSION

Addition of naloxone to oxycodone PR tablets in a pain regimen administered twice daily the first three post-operative days had no significant clinical effects on constipation or other variables during the first week after hysterectomy.

Single dose oral analgesics for acute postoperative pain in adults

BACKGROUND

Thirty-five Cochrane Reviews of randomised trials testing the analgesic efficacy of individual drug interventions in acute postoperative pain have been published. This overview brings together the results of all those reviews and assesses the reliability of available data.

OBJECTIVES

To summarise data from all Cochrane Reviews that have assessed the effects of pharmaceutical interventions for acute pain in adults with at least moderate pain following surgery, who have been given a single dose of oral analgesic taken alone.

METHODS

We identified systematic reviews in The Cochrane Library through a simple search strategy. All reviews were overseen by a single Review Group, had a standard title, and had as their primary outcome numbers of participants with at least 50% pain relief over four to six hours compared with placebo. For individual reviews we extracted the number needed to treat (NNT) for this outcome for each drug/dose combination, and also the percentage of participants achieving at least 50% maximum pain relief, the mean of mean or median time to remedication, the percentage of participants remedicating by 6, 8, 12, or 24 hours, and results for participants experiencing at least one adverse event.

MAIN RESULTS

The overview included 35 separate Cochrane Reviews with 38 analyses of single dose oral analgesics tested in acute postoperative pain models, with results from about 45,000 participants studied in approximately 350 individual studies. The individual reviews included only high-quality trials of standardised design and outcome reporting. The reviews used standardised methods and reporting for both efficacy and harm. Event rates with placebo were consistent in larger data sets. No statistical comparison was undertaken.There were reviews but no trial data were available for acemetacin, meloxicam, nabumetone, nefopam, sulindac, tenoxicam, and tiaprofenic acid. Inadequate amounts of data were available for dexibuprofen, dextropropoxyphene 130 mg, diflunisal 125 mg, etoricoxib 60 mg, fenbufen, and indometacin. Where there was adequate information for drug/dose combinations (at least 200 participants, in at least two studies), we defined the addition of four comparisons of typical size (400 participants in total) with zero effect as making the result potentially subject to publication bias and therefore unreliable. Reliable results were obtained for 46 drug/dose combinations in all painful postsurgical conditions; 45 in dental pain and 14 in other painful conditions.NNTs varied from about 1.5 to 20 for at least 50% maximum pain relief over four to six hours compared with placebo. The proportion of participants achieving this level of benefit varied from about 30% to over 70%, and the time to remedication varied from two hours (placebo) to over 20 hours in the same pain condition. Participants reporting at least one adverse event were few and generally no different between active drug and placebo, with a few exceptions, principally for aspirin and opioids.Drug/dose combinations with good (low) NNTs were ibuprofen 400 mg (2.5; 95% confidence interval (CI) 2.4 to 2.6), diclofenac 50 mg (2.7; 95% CI 2.4 to 3.0), etoricoxib 120 mg (1.9; 95% CI 1.7 to 2.1), codeine 60 mg + paracetamol 1000 mg (2.2; 95% CI 1.8 to 2.9), celecoxib 400 mg (2.5; 95% CI 2.2 to 2.9), and naproxen 500/550 mg (2.7; 95% CI 2.3 to 3.3). Long duration of action (≥ 8 hours) was found for etoricoxib 120 mg, diflunisal 500 mg, oxycodone 10 mg + paracetamol 650 mg, naproxen 500/550 mg, and celecoxib 400 mg.Not all participants had good pain relief and for many drug/dose combinations 50% or more did not achieve at last 50% maximum pain relief over four to six hours.

AUTHORS' CONCLUSIONS

There is a wealth of reliable evidence on the analgesic efficacy of single dose oral analgesics. There is also important information on drugs for which there are no data, inadequate data, or where results are unreliable due to susceptibility to publication bias. This should inform choices by professionals and consumers.

Adherence and long-term effect of oxycodone/paracetamol in chronic noncancer pain: a retrospective study

INTRODUCTION

Long-term administration of opiates in patients with chronic noncancer pain (CNCP) is subject to debate due to insufficient clinical evidence to support efficacy and tolerability.

METHODS

This retrospective analysis used hospital records to investigate the effects of low doses of the combination of oxycodone/paracetamol on CNCP in an outpatient clinic setting to verify adherence to therapy and long-term efficacy. All patients receiving therapy for CNCP were examined between May and September 2010 and information was collected on medication, duration of therapy, and static and dynamic pain measured using numeric rating scales (NRS) from relevant charts.

RESULTS

Two hundred and thirty-one patients (157 men, 68%) with a mean (± SD) age of 66.4±15.5 years were analyzed. Pain indexes at baseline revealed a mean (± SD) static NRS (sNRS) of 3.5±1.77 and a mean dynamic NRS (dNRS) of 7.24±1.33. At last follow-up, mean (± SD) pain reductions versus baseline were 1.58±1.42 for sNRS and 3.04±1.43 for dNRS (P<0.0001 for both). Regarding the duration of therapy, 54 patients (23.4%) were treated for <4 months, and 177 patients (76.6%) for 4 months up to 23 months. Pain reduction was significant in all groups (P<0.0001) but was greatest in patients who had been receiving therapy for ≥4 months. Improvements in pain relief were not associated with an increase in daily dose, which remained stable or decreased slightly over time.

DISCUSSION

The results of this study support the hypothesis that an opiate-based combination at low doses improves tolerability and adherence and results in patients obtaining long-term efficacy. Larger studies of the use of opiates in this setting and clinical monitoring on the regional and national level may convince clinicians to view opiates as efficacious analgesics and not as dangerous substances of abuse.

Single dose oral diflunisal for acute postoperative pain in adults

BACKGROUND

Diflunisal is a long-acting non-steroidal anti-inflammatory drug (NSAID) most commonly used to treat acute postoperative pain or chronic joint pain from osteoarthritis and rheumatoid arthritis. This review analyses the effectiveness and harm of different doses of diflunisal in the context of moderate to severe postoperative pain.

OBJECTIVES

To assess efficacy, duration of action, and associated adverse events of single dose oral diflunisal in acute postoperative pain in adults.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to January 2010.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled trials of single dose orally administered diflunisal in adults with moderate to severe acute postoperative pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which relative risk and number-needed-to-treat-to-benefit (NNT) were calculated. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals were collected.

MAIN RESULTS

Nine studies in dental, orthopedic and gynaecological surgery met the inclusion criteria, testing doses of diflunisal from 125 mg to 1000 mg.For diflunisal 1000 mg, the NNT for at least 50% pain relief over 4 to 6 hours was 2.1 (1.8 to 2.6) (6 studies, 391 participants); the NNT to prevent remedication within 6 hours was 1.9 (1.7 to 2.3), and within 12 hours was 2.2 (1.9 to 2.7) (6 studies, 409 participants). More participants experienced adverse events with diflunisal 100 mg than with placebo, but none were serious or led to withdrawal.For diflunisal 500 mg, the NNT for at least 50% pain relief over 4 to 6 hours was 2.6 (2.1 to 3.3) (6 studies, 357 participants); the NNT to prevent remedication within 6 hours was 2.6 (2.1 to 3.4) (6 studies, 390 participants), and within 12 hours was 2.9 (2.3 to 4.0) (5 studies, 329 participants). Adverse events did not differ significantly from placebo.

AUTHORS' CONCLUSIONS

Diflunisal has an analgesic effect similar to other NSAIDs in single dose, but benefits from providing significant analgesia for about twelve hours. This property may be useful when regular dosing is needed, or when taking several doses of a shorter acting analgesic is impractical.

Single dose oral fenbufen for acute postoperative pain in adults

BACKGROUND

Fenbufen is a non-selective non-steroidal anti-inflammatory drug (NSAID), used to treat acute and chronic painful conditions. There is no known systematic review of its use in acute postoperative pain.

OBJECTIVES

To assess efficacy, duration of action, and associated adverse events of single dose oral fenbufen in acute postoperative pain in adults.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief database for studies to June 2009.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled trials of single dose orally administered fenbufen in adults with moderate to severe acute postoperative pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which relative risk and number needed to treat to benefit (NNT) were calculated. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals were collected.

MAIN RESULTS

Searches identified only one study with (90 participants in total, 31 taking fenbufen). The study compared oral fenbufen 800 mg, fenbufen 400 mg, and placebo in participants with established postoperative pain. Fenbufen at both doses had apparent analgesic efficacy, but the numbers of participants was too small to allow sensible analysis. Gastrointestinal adverse events were noted in 4 of 15 participants taking fenbufen 800 mg.

AUTHORS' CONCLUSIONS

In the absence of evidence of efficacy for oral fenbufen in acute postoperative pain, its use in this indication is not justified at present. Because trials clearly demonstrating analgesic efficacy in the most basic of acute pain studies is lacking, use in other indications should be evaluated carefully. Given the large number of available drugs of this and similar classes which are effective, there is no urgent research agenda for this particular drug.

Single dose oral sulindac for acute postoperative pain in adults

BACKGROUND

Sulindac is a non-steroidal anti-inflammatory drug (NSAID) licensed for use in rheumatic disease and other musculoskeletal disorders in the UK, and widely available in other countries worldwide. This review sought to evaluate the efficacy and safety of oral sulindac in acute postoperative pain, using clinical studies of patients with established pain, and with outcomes measured primarily over 6 hours using standard methods. This type of study has been used for many decades to establish that drugs have analgesic properties.

OBJECTIVES

To assess the efficacy of single dose oral sulindac in acute postoperative pain, and any associated adverse events.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies up to June 2009.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled clinical trials of oral sulindac for relief of acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We planned to use area under the "pain relief versus time" curve to derive the proportion of participants with meloxicam experiencing least 50% pain relief over 4 to 6 hours, using validated equations; to use number needed to treat to benefit (NNT); the proportion of participants using rescue analgesia over a specified time period; time to use of rescue analgesia; information on adverse events and withdrawals.

MAIN RESULTS

No studies were identified by the searches that examined oral sulindac in patients with established postoperative pain.

AUTHORS' CONCLUSIONS

In the absence of evidence of efficacy, at present, for oral sulindac in acute postoperative pain, its use in this indication is not justified. Because trials clearly demonstrating analgesic efficacy in the most basic of acute pain studies is lacking, use in other indications should be evaluated carefully. Given the large number of available drugs of this and similar classes, there is no urgent research agenda.