Randomized, double-blind, placebo-controlled comparison of the analgesic efficacy of oxycodone 10 mg/acetaminophen 325 mg versus controlled-release oxycodone 20 mg in postsurgical pain

Efficacy of oxycodone for postoperative dental pain: A systematic review and meta-analysis

OBJECTIVES

Dental pain is a commonly managed presentation in medicine and dentistry, where oxycodone is often prescribed. The aim of this systematic review and meta-analysis was to determine and quantify the effectiveness of oxycodone for acute dental pain.

DATA

Randomised controlled trials, controlled trials and comparative studies were included involving patients >12 years, where oxycodone was trialled for dental pain.

SOURCES

Three databases were searched: Medline Ovid, Embase Ovid and Web of Science. Two authors independently screened title and abstracts for relevance, extracted data and performed bias assessments.

STUDY SELECTION

Of 148 potentially relevant studies, 13 articles met the inclusion criteria for the systematic review and of the 13, nine studies were included in the meta-analysis. All studies were single-dose analgesia for surgical third molar extractions.

CONCLUSIONS

Oxycodone produced more effective analgesia in combination with paracetamol. In the meta-analysis, monotherapy etoricoxib and rofecoxib showed significant pain relief compared to combination oxycodone/paracetamol (SPID6 mean difference=-2.13, CI=-3.29, -0.98; TOTPAR6 mean difference=-2.98, CI=-4.90, -1.06). Non-steroidal anti-inflammatory drugs (NSAIDs) were more effective than oxycodone/paracetamol combinations, however, the evidence would become weak in a future study with a similar patient setting due to substantial statistical heterogeneity (SPID6 and TOTPAR6 prediction interval -4.471, 0.207 and -7.28, 1.32 respectively).

CLINICAL SIGNIFICANCE

Non-steroidal anti-inflammatory drugs were superior than oxycodone/paracetamol combinations, although some patient populations may experience similar effects to the combined oxycodone/paracetamol combination.

Application of oxycodone in anesthesia induction and overall management of Da Vinci robot-assisted nephrectomy: A randomized controlled trial

BACKGROUND

This study aimed to evaluate the application of oxycodone in anesthesia induction and overall management of Da Vinci robot-assisted nephrectomy.

METHODS

A total of 42 patients undergoing Da Vinci robot-assisted nephrectomy with general anesthesia were selected. They were randomly divided into 2 groups: patients were induced with oxycodone (oxycodone group) and were induced with sufentanil (sufentanil group). The vital signs at the following time points were recorded: after injection of induced drugs (T1), during glottis exposure (T2), immediately after intubation (T3), 1 minute (T4), 2 minute (T5), 3 minute (T6), 5 minute (T7), 10 minute (T8) after intubation, during skin incision (T9), at the end of suturing skin (T10), during extubation (T11), and during hemodynamic fluctuations intraoperatively (T`). Numerical rating scale, facial affective scale and monitoring of adverse events (visual analogue scale, NVAS) were evaluated postoperatively at 1 hour (T'"1), 3 hours (T""2), 6 hours (T""3), 12 hours (T""4), 24 hours (T""5), and 48 hours (T"'6).

RESULTS

The systolic blood pressure, the diastolic blood pressure and the mean arterial blood pressure showed no statistically different changes between the 2 groups. There were no statistical differences in heart rate and respiratory rate among various timepoints intraoperatively. There were statistical differences in Bispectral index (BIS) scores in T6 between the 2 groups. The numerical rating scale and facial affective scale scores were significantly lower in oxycodone group. Anesthetized with oxycodone, the pain did not affect the sleep of patients after operation. Also, the postoperative QoR-40 scores were lower in oxycodone group.

CONCLUSION

Compared with sufentanil, anesthesia induction with 0.3 mg/kg oxycodone in Da Vinci robot-assisted nephrectomy can achieve mild pain and mild adverse responses in patients postoperatively.

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.

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.

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.

New health care measures: emphasis on better management of postsurgical pain and postoperative nausea and vomiting

Value-based purchasing and the Hospital Consumer Assessment of Healthcare Providers and Systems are tying patient-centric measures to reimbursements. Hospitals should be particularly concerned about management of postoperative pain and control of postoperative nausea and vomiting (PONV), known to adversely impact overall patient satisfaction. Anesthesiologists are likely to be on the frontlines of these transitions. Although postoperative pain is not always effectively managed, clinicians have the pharmacological tools and guidelines for better pain control. Considerable work has been done in PONV to better identify high-risk patients and effective prophylactic agents. Postoperative pain control and preventing PONV are two relatively straightforward ways to respond to new quality metrics. The aim of this review is to raise practitioner awareness of these new quality metrics and provide an overview of the current tools and methods used to improve postoperative pain control and PONV.

A randomized, double-blind, placebo-controlled study of the efficacy and safety of MNK-795, a dual-layer, biphasic, immediate-release and extended-release combination analgesic for acute pain

OBJECTIVE

To investigate the efficacy and safety of a bilayer combination oxycodone (OC) and acetaminophen (APAP) analgesic with both immediate-release and extended-release (ER) components (OC/APAP ER) in patients with moderate to severe pain using an established acute pain model.

RESEARCH DESIGN AND METHODS

This was a randomized, double-blind, placebo-controlled trial. Adult patients were included in the study if they had a pain intensity score≥4 on a 0-10 numerical rating scale after bunionectomy surgery, and were randomized (1:1) to receive four doses (two tablets q12h) of OC/APAP ER or placebo.

CLINICAL TRIAL REGISTRATION

NCT01484652.

MAIN OUTCOME MEASURES

The primary efficacy endpoint was the summed pain intensity difference over the first 48 hours (SPID48). Secondary endpoints included SPIDs and total pain relief (TOTPAR) over the dosing intervals; time to perceptible, meaningful, and confirmed pain relief; and the proportion of patients with ≥30% reduction in pain intensity scores.

RESULTS

A total of 329 patients were enrolled, of whom 266 (OC/APAP ER, n=135; placebo, n=131) completed the study. The mean (SE) SPID48 was 114.9 (7.6) in the OC/APAP ER group and 66.9 (7.6) in the placebo group (P<0.0001). SPID and TOTPAR values were significantly greater with OC/APAP ER than with placebo over all time periods analyzed, and the median times to perceptible, meaningful, and confirmed pain relief were significantly shorter. More patients showed ≥30% reduction in pain intensity scores with OC/APAP ER than with placebo at all times after 0.5 hours. OC/APAP ER was generally well tolerated. A limitation of this study was the lack of an active comparator.

CONCLUSIONS

OC/APAP ER was efficacious and generally well tolerated in an established model of moderate to severe acute pain, providing an onset of analgesia in approximately 30 minutes and sustained pain relief over the 12 hour dosing period.

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.

Long-acting morphine following hip or knee replacement: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Patients undergoing total hip or knee replacement surgery experience unmanaged pain during postoperative physiotherapy sessions. It was theorized that a baseline opioid would improve pain management.

OBJECTIVES

To examine the effectiveness of adding long-acting oral morphine to a routine postoperative regimen for total hip or knee replacement surgery.

METHODS

The present study was a double-blind, randomized, placebo-controlled trial for patients undergoing total hip or knee replacement surgery. All patients received routine postoperative analgesia; in addition, the treatment group received long-acting oral morphine 30 mg orally twice daily for three days, while the control group received placebo capsules. The primary end point was a decrease in pain scores by two points on a 0- to 10-point pain rating scale. Secondary end points included adverse effects, acute confusion, pain-related interferences in function and sleep, length of stay and patient satisfaction.

RESULTS

Two hundred patients were enrolled in the present study (March 2004 to March 2006). Although the groups were large enough to yield statistical significance, most pain scores did not reach the predetermined improvement for clinical significance. Additionally, there was an increase in opioid usage (P<0.0001), vomiting (P=0.0148) and oversedation (P=0.08). There were no statistically significant changes in function or sleep. Improved satisfaction with pain management was minimal (P=0.052).

DISCUSSION

The present study was undertaken to determine the value of adding a long-acting opioid (morphine) to the usual care of patients undergoing total hip or total knee replacement surgery. The results yielded minimally improved pain scores and additional adverse effects (vomiting and oversedation). Published research in which long-acting opioids (oxycodone) were used for similar postoperative procedures did not robustly report improved pain scores. In addition, patients using a long-acting opioid (oxycodone) during the postoperative period reported somnolence, dizziness and confusion. Statistically, the patients in the present study showed higher confusion scores and no improvement for pain-related interferences with activity or walking. The treatment group did report increased satisfaction; however, the significance was weak.

CONCLUSIONS

Thirty milligrams twice per day of long-acting morphine from days 1 to 3 following total hip and total knee replacement surgery provided minimal improvements in pain scores, and more adverse effects in the treatment group. The overall strength of evidence for improved outcomes is minimal and thus not supported.

Liver cancer: effects, safety, and cost-effectiveness of controlled-release oxycodone for pain control after TACE

PURPOSE

To evaluate the analgesic effect, safety, and cost-effectiveness of controlled-release oxycodone (CRO) to control postoperative pain in patients with liver cancer who are undergoing transarterial chemoembolization.

MATERIALS AND METHODS

This randomized, double-blind, placebo-controlled, prospective clinical study received institutional review board approval. After written informed consent was obtained, 210 patients with liver cancer were randomized into three groups of 70 patients. Group 1 received 20 mg of CRO, group 2 received 10 mg of CRO, and group 3 received a placebo at 1 hour before transarterial chemoembolization (T(0)) and 12 (T(12)) and 24 (T(24)) hours after T(0). Pain intensity on a numeric rating scale, percentage of patients with each degree of pain, quality of life, adverse reactions, analgesic costs, and hospital stays were evaluated and compared among the three groups.

RESULTS

Numeric rating scale scores for pain intensity in group 1 and group 2 were significantly lower than those in group 3 at T(0-12) (P < .001); T(12-24) (P < .001); and T(24-48) (P < .001). When group 1 with group 2 were compared, numeric rating scale scores were significantly lower in group 1 than in group 2 during the period of T(0-12) (P < .001) but were not significantly different at T(12-24) (P = .68) and T(24-48) (P = .10). Analgesic cost and hospital stay were significantly lower in treated groups than in the placebo group. No significant difference was observed in quality of life and adverse events between the treated groups and the placebo group.

CONCLUSION

CRO is effective, safe, and cost-effective in the control of postoperative pain after transarterial chemoembolization for patients with inoperable liver cancer.

Continuous multimechanistic postoperative analgesia: a rationale for transitioning from intravenous acetaminophen and opioids to oral formulations

Good surgical outcomes depend in part on good pain relief, allowing for early mobilization, optimal recovery, and patient satisfaction. Postsurgical pain has multiple mechanisms, and multimechanistic approaches to postoperative analgesia are recommended and may be associated with improved pain relief, lowered opioid doses, and sometimes a lower rate of opioid-associated side effects. Acetaminophen (paracetamol) is a familiar agent for treating many types of pain, including postsurgical pain. Oral acetaminophen has been shown to be safe and effective in a variety of acute pain models. Combination products using a fixed-dose of acetaminophen and an opioid have also been effective in treating postsurgical pain. Combination products with acetaminophen have demonstrated an opioid-sparing effect, which inconsistently results in a reduced rate of opioid-associated side effects. Intravenous (IV) acetaminophen and an opioid analgesic administered in the perioperative period may be followed by an oral acetaminophen and opioid combination in the postoperative period. Transitioning from an IV acetaminophen and opioid formulation to a similar but oral formulation of the same drugs appears to be a reasonable step in that both analgesic therapies are known to be safe and effective. For postsurgical analgesia with any acetaminophen product, patient education is necessary to be sure that the patient does not concurrently take any over-the-counter products containing acetaminophen and accidentally exceed dose limits.

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.

Efficacy of oxycodone/paracetamol for patients with bone-cancer pain: a multicenter, randomized, double-blinded, placebo-controlled trial

WHAT IS KNOWN AND OBJECTIVE

Bone-cancer pain is a common and refractory cancer pain. Opioids, on their own, do not control this type of pain well enough, and co-analgesics are necessary.

METHODS

Patients with bone metastasis-related pain at Numeric Rating Scale ≥4 were enrolled to this randomized placebo-controlled trial. They had also received morphine or transdermal fentanyl patches for at least 1 week. During the 3-day efficacy phase, patients received placebo or 1-3 tablets of oxycodone/paracetamol (5/325 mg), four times daily for 3 days. All patients kept a daily pain diary. The primary endpoint was the Pain Intensity Difference (PID). Secondary endpoints were cases of breakthrough pain and rescue morphine consumption. Additional analyses included the Short Form-6 Dimensions (SF-6D) quality-of-life scale and a general impression (GI) of patient satisfaction with treatment at the end of the phase.

RESULTS AND DISCUSSION

Of the 246 patients in the intent-to-treat set, 89·4% completed the 3-day efficacy phase. PIDs were 0·9 and 0·3 in the oxycodone/paracetamol and placebo groups respectively, on day 1 (P < 0·001), and 1·5 and 0·3 respectively on day 3 (P < 0·001). Thirty-eight patients in the treatment group, and 58 in the placebo group, suffered breakthrough pain on day 3 (P < 0·001). The SF-6D score decreased to 21·2 ± 2·5 in the oxycodone/paracetamol group at the end of the phase (P = 0·001). In the oxycodone/paracetamol group, 67% rated GI as good, very good, or excellent.

WHAT IS NEW AND CONCLUSION

Patients with bone-cancer pain, already on opioids, obtain clinically important, additional pain-control, with regular oxycodone/paracetamol dosing.

Oxycodone combinations for pain relief

No single analgesic drug provides the perfect therapeutic/adverse effect profile for every pain condition. In addition to convenience and possibly improved compliance, a combination of analgesic drugs offers the potential, requiring verification, of providing greater pain relief and/or reduced adverse effects than the constituent drugs when used individually. We review here analgesic combinations containing oxycodone. We found surprisingly little preclinical information about the analgesic or adverse effect profiles of the combinations (with acetaminophen, paracetamol, nonsteroidal anti-inflammatory drugs, morphine, gabapentin or pregabalin). Clinical experience and studies suggest that the combinations are safe and effective and may offer certain advantages. As with all combinations, the profile of adverse effects must also be determined in order to provide the clinician with the overall benefit/risk assessment.

Pain syndromes in sickle cell disease: an update

OBJECTIVE

Pain has a critical role in the management of sickle cell disease (SCD). Patients may suffer from several pain syndromes, which may be or not may be associated with other clinical complications, such as anemia, organ failures, and infections.

DESIGN

Data for review were identified by using PubMed to search MEDLINE, limiting the search to abstract/articles in English, Italian, French, and Dutch. The key words pain, sickle cell disease, anemia, hemoglobin, hemoglobinopathy, analgesics, opioids, morphine, acetaminophen, paracetamol, nonsteroidal anti-inflammatory drugs, hematology, and quality of life were variously combined in the title, abstract, and key word search list. The abstract database of most hematological congresses and the bibliographies of most relevant articles were also considered.

RESULTS

There are two major types of SCD pain: acute and chronic. Sometimes, mixed and neuropathic pain can be also observed. Acute pain is mostly related to vaso-occlusion. Chronic pain may be due to some SCD complications, such as leg ulcers and avascular necrosis.

CONCLUSIONS

Pain management in the SCD setting needs multidisciplinary approaches, given the several syndromes and the pathogenic mechanisms that are likely involved. Pain management is not standardized and often difficult, so that many patients with SCD are still poorly treated. Further efforts to develop care plans and treatment protocols as well as management guidelines are required.

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

BACKGROUND

Oxycodone is a strong opioid agonist used to treat severe pain. It is commonly combined with milder analgesics such as paracetamol. This review updates a previous review that concluded, based on limited data, that all doses of oxycodone exceeding 5 mg, with or without paracetamol, provided analgesia in postoperative pain, but with increased incidence of adverse events compared with placebo. Additional new studies provide more reliable estimates of efficacy and harm.

OBJECTIVES

To assess efficacy, duration of action, and associated adverse events of single dose oral oxycodone, with or without paracetamol, in acute postoperative pain in adults.

SEARCH STRATEGY

Cochrane CENTRAL, MEDLINE, EMBASE and Oxford Pain Relief Database, searched in May 2009.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled trials of single dose orally administered oxycodone, with or without paracetamol, 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 remedicating over specified time periods, and time-to-use of rescue medication, were sought as additional measures of efficacy. Adverse events and withdrawals information was collected.

MAIN RESULTS

This updated review includes 20 studies, with 2641 participants. For oxycodone 15 mg alone compared with placebo, the NNT for at least 50% pain relief was 4.6 (95% Confidence Interval 2.9 to 11). For oxycodone 10 mg plus paracetamol 650 mg, the NNT was 2.7 (2.4 to 3.1). A dose response was demonstrated for this outcome with combination therapy. Duration of effect was 10 hours with oxycodone 10 mg plus paracetamol 650 mg, and 4 hours with half that dose. Fewer participants needed rescue medication over 6 hours at the higher dose. Adverse events occurred more frequently with combination therapy than placebo, but were generally described as mild to moderate in severity and rarely led to withdrawal.

AUTHORS' CONCLUSIONS

Single dose oxycodone is an effective analgesic in acute postoperative pain at doses over 5 mg; oxycodone is two to three times stronger than codeine. Efficacy increases when combined with paracetamol. Oxycodone 10 mg plus paracetamol 650 mg provides good analgesia to half of those treated, comparable to commonly used non-steroidal anti-inflammatory drugs, with the benefit of longer duration of action.

Early oral analgesia after fast-track cardiac anesthesia

PURPOSE

Oral analgesia after "fast-track" cardiac anesthesia has not been explored. The aim of this study was to compare two oral oxycodone analgesic regimens.

METHODS

One hundred-twenty patients scheduled for coronary artery bypass grafting were randomly assigned postoperatively to receive immediate-release oxycodone 5 mg and acetaminophen 325 mg (Percocet-5) (group I) per os four times daily, or controlled-release oxycodone 10 mg (OxyContin) (group II) per os every 12 hr and placebo twice daily. Acetaminophen 500 mg per os was used as first-line rescue medication, and immediate-release oxycodone (syrup form) 5 mg per os as second-line rescue medication. Pain intensity was assessed with a visual analogue scale on the first postoperative day, the morning after extubation, and thereafter four times daily for four days. Use of rescue medication and adverse events were recorded.

RESULTS

Baseline demographic and operation-related characteristics were similar in both groups. While pain control was good in both groups, the immediate-release group experienced less pain on all postoperative days (P = 0.003), required significantly less rescue medication, and had fewer adverse effects such as somnolence and nausea.

CONCLUSION

Peroral oxycodone is effective for early pain control after fast-track cardiac anesthesia. Immediate-release oxycodone/ acetaminophen appears to provide better analgesia and fewer side effects compared to controlled-release oxycodone.

Efficacy and Tolerability of Oxycodone Hydrochloride Controlled-Release Tablets in Moderate to Severe Cancer Pain

BACKGROUND AND OBJECTIVE

Oxycodone is a semisynthetic opioid analgesic drug classed as a strong opioid. The controlled-release oxycodone tablet formulation (OCRT) was approved in China in 2004 for management of moderate to severe cancer pain. Few data about the efficacy of OCRT and clinical outcomes in Chinese patients taking this drug are available. The purpose of this study was to evaluate the efficacy and tolerability of this drug for relief of moderate to severe cancer pain in Chinese patients.

METHODS

This was a prospective, open-label, multicentre clinical trial carried out in ten hospitals in Zhejiang Province, China. Patients with cancer pain with a score > or =4 (numerical rating scale) were enrolled. They received oral OCRT at an initial dosage of 5mg every 12 hours for patients scoring 4-6 and 10mg every 12 hours for patients scoring > or =7. Doses were then titrated on an individual basis. Onset of analgesic action, pain score and quality-of-life (QOL) scores - including items measuring family understanding and support, sleep, mental state, appetite, fatigue, and activities of daily life - were evaluated. Adverse effects were also documented.

RESULTS

216 patients (126 males and 90 females) aged 22-84 years were enrolled. The total mean OCRT dosage was 445.2 +/- 361.6mg (range 130-2320mg). The daily dosages of the vast majority of cases (89%) were between 10mg and 30mg. Onset of analgesic action occurred within 1 hour in 198 cases (91.7%) following administration of OCRT. 82.4% of cases were titrated to a steady dosage level within 2 days following administration of the first dose of medication. Pain score decreased significantly (p < 0.01) from 7.1 +/- 1.2 at baseline to 2.3 +/- 1.2 one week after starting medication and 1.8 +/- 0.9 four weeks after starting medication. Scores on all six QOL items increased significantly (p < 0.01) compared with baseline but showed varying rates of improvement. Adverse events included constipation, nausea, vomiting, drowsiness and dysuria. These were noted most frequently in the first week (25.5% of patients) and lessened over time. No severe adverse events were noted.

CONCLUSION

We conclude that OCRT is well tolerated and effective in controlling moderate to severe cancer pain in Chinese patients.

Oxymorphone Extended-Release Tablets Relieve Moderate to Severe Pain and Improve Physical Function in Osteoarthritis: Results of a Randomized, Double-Blind, Placebo- and Active-Controlled Phase III Trial

OBJECTIVE

To compare oxymorphone extended release (ER) and placebo on indices of pain, function, and safety in patients with chronic osteoarthritis (OA) pain.

DESIGN

In this multicenter, double-blind, placebo- and active-controlled, parallel-group, dose-ranging study, patients were randomized to oxymorphone ER 20 mg (N = 121), oxymorphone ER 40 mg (N = 121), oxycodone controlled release 20 mg (N = 125), or placebo (N = 124) every 12 hours. The primary efficacy end point was change in arthritis pain intensity (visual analog scale, 0-100) from baseline to week 3 for the oxymorphone ER 40 mg group versus placebo.

RESULTS

The primary end point was achieved: the week 3 oxymorphone ER least squares mean difference (LSMD) from placebo was -9.0 (95% confidence interval [CI]: -16.2 to -1.8; P = 0.015). Secondary efficacy analysis showed similar improvements at week 4 (LSMD from placebo, -10.3 [95% CI: -17.7 to -2.8]; P = 0.007) and with oxymorphone ER 20 mg at week 3 (LSMD from placebo, -7.7 [95% CI: -15.0 to -0.4]; P = 0.039) and week 4 (LSMD from placebo, -7.5 [95% CI: -15.0 to 0.0]; P = 0.050). Weeks 3 and 4 pain intensity decreased by approximately 30-40%. Oxymorphone ER 20 and 40 mg improved from baseline on the Western Ontario and McMaster Universities Osteoarthritis Composite Index and pain and physical function subscales at week 4. Adverse events in all opioid groups included mild to moderate nausea, constipation, and somnolence.

CONCLUSIONS

In this short-term study, oxymorphone ER was superior to placebo for relieving pain and improving function in patients with moderate to severe chronic OA pain, and is an alternative to other sustained-release opioids.

Comparison of rofecoxib and oxycodone plus acetaminophen in the treatment of acute pain: a randomized, double-blind, placebo-controlled study in patients with moderate to severe postoperative pain in the third molar extraction model

BACKGROUND

Opiates, acetaminophen, nonselective nonsteroidal anti-inflammatory drugs (NSAIDs), and cyclooxygenase-2-selective inhibitors such as rofecoxib are used in the treatment of acute pain because of their anti-inflammatory and/or analgesic properties. Rofecoxib has demonstrated an improved gastrointestinal safety profile compared with nonselective NSAIDs.

OBJECTIVE

The aim of this study was to compare the analgesic efficacy and tolerability profile of rofecoxib 50 mg with those of the centrally acting, nonsalicylate, opiate/nonopiate analgesic combination oxycodone/acetominophen 5/325 in patients with pain after dental surgery.

METHODS

In this randomized, double-blind, placebo- and active comparator-controlled study, patients experiencing moderate to severe postoperative pain after extraction of > or =2 third molars (including > or =1 mandibular impaction) received a single oral dose of rofecoxib 50 mg, oxycodone/acetaminophen 5/325 mg, or placebo. End points included total pain relief over 6 hours (TOPAR6, the primary end point) and 4 hours (TOPAR4), patient's global assessment of treatment at 6 hours (GLOBAL6) and 24 hours (GLOBAL24), summed pain intensity difference over 6 hours (SPID6), onset of analgesic effect (time to perceptible/meaningful pain relief, using a 2-stopwatch method), peak pain relief (PEAKPR), peak pain intensity difference (PEAKPID), and duration of analgesic effect (time to use of rescue analgesia).

RESULTS

Two hundred twelve patients (63% female, 37% male; 76% white, 24% other; mean [SD] age, 20.9 [4.4] years; age range, 16-41 years) were enrolled in the study and received a single oral dose of rofecoxib 50 mg (n = 90), oxycodone/acetaminophen 5/325 mg (n = 91), or placebo (n = 31). The analgesic effect of rofecoxib was significantly greater than that of oxycodone/acetaminophen at P < 0.001 for TOPAR6, TOPAR4, GLOBAL6, GLOBAL24, and SPID6; at P < 0.010 for PEAKPR and PEAKPID; and at P < 0.001 for median time to use of rescue analgesia. Significantly fewer patients in the rofecoxib group (72.2%) took rescue analgesia within 24 hours postdose compared with the oxycodone/acetaminophen group (94.5%; P < 0.001) and the placebo group (96.8%; P < 0.02). Both active treatments were similar with respect to onset of analgesic effect. Both were generally well tolerated; the overall incidence of adverse experiences in the rofecoxib, oxycodone/acetaminophen, and placebo groups was 51.1%, 64.8%, and 48.4%, respectively. Rofecoxib was associated with a significantly lower incidence of nausea (18.9% vs 39.6%; P < 0.001) and vomiting (6.7% vs 23.1%; P < 0.001) compared with oxycodone/acetaminophen.

CONCLUSIONS

In study patients with moderate to severe pain after dental surgery, rofecoxib 50 mg had a greater analgesic effect than oxycodone/acetaminophen 5/325 mg and was associated with less nausea and vomiting.

Comparison of rofecoxib and a multidose oxycodone/ acetaminophen regimen for the treatment of acute pain following oral surgery: a randomized controlled trial

OBJECTIVE

To compare the efficacy of a single dose of rofecoxib 50 mg with a single dose of oxycodone/acetaminophen 10/650 mg over 6 h as well as with a multidose regimen of oxycodone/acetaminophen 10/650 mg followed by oxycodone/acetaminophen 5/325 mg over 24 h.

RESEARCH DESIGN AND METHODS

In this double-blind, randomized, two-phase study, patients with moderate to severe pain after surgical extraction of >or= 2 third molars, including one mandibular impaction, were treated with rofecoxib 50 mg, oxycodone/acetaminophen 10/650 mg (singledose phase) followed by 5/325 mg every 6h as needed (multidose phase), or placebo. Patients rated their pain relief and intensity at 18 time points over 24 h. Efficacy was measured over 6 and 24 h by total pain relief (TOPAR), sum of pain intensity difference (SPID), and patient global assessment of response to therapy (PGART). Primary endpoint for the single dose comparison was TOPAR over 6 h; SPID was the key 24-h endpoint. Onset of analgesic effect, peak analgesic single dose of oxycodone/acetaminophen. effect, and duration of analgesic effect were also evaluated. Adverse experiences were recorded.

RESULTS

271 patients were randomized to treatment with rofecoxib (n = 121), oxycodone/acetaminophen (n = 120), or placebo (n = 30). For the single dose comparison, rofecoxib-treated patients achieved pain relief at least as effective as oxycodone/acetaminophentreated patients as assessed by TOPAR6 (12.9 vs 11.3, 95% CI on difference = [-0.1, 3.2], p = 0.059). Patients also rated a single dose of rofecoxib as at least as effective as multidose oxycodone/acetaminophen over 24 h on SPID24 (21.9 vs 18.1, 95% CI on difference = [-1.0, 8.8], p = 0.122). Patients treated with oxycodone/ acetaminophen had a shorter time to onset of analgesia than patients treated with rofecoxib (24 vs 35 min, p < 0.05). Patients in the active treatment groups achieved similar peak effects during the single-dose phase. Individuals treated with rofecoxib demonstrated a longer duration of analgesic effect than those treated with a Patients on active treatment demonstrated better efficacy than patients on placebo on these prespecified endpoints (p < 0.001 for both comparisons). Fewer rofecoxib than oxycodone/acetaminophen patients experienced adverse events (47.9 vs 75.8%, p < 0.001), including nausea (19.0 vs 42.5%, p < 0.001), vomiting (9.9 vs 24.2%, p < 0.01), and dizziness (7.4 vs 31.7%, p < 0.001).

CONCLUSION

Patients treated with a single dose of rofecoxib 50 mg achieved an overall analgesic effect at least as effective as patients treated with a single-dose of oxycodone/acetaminophen 10/650 mg over 6 h and multidose oxycodone/acetaminophen over 24 h, with fewer adverse experiences of nausea (p < 0.001), vomiting (p < 0.01), and dizziness (p < 0.001).

Synergy between the antinociceptive effects of morphine and NSAIDs

The intraperitoneal administration of morphine, diclofenac, ketoprofen, meloxicam, metamizol, paracetamol and piroxicam induced dose-dependent antinociception in mice tested with the acetic acid writhing test. The isobolographic analysis of the simultaneous intraperitoneal administration of fractions of the ED50's of morphine with each nonsteroidal anti-inflammatory drug (NSAID) demonstrated the existence of a supra-additive interaction (synergy). The selective antagonist of µ-opioid receptors naltrexone partially reversed the supra-additive interactions to additive interactions; however, the combinations of morphine/metamizol and morphine/paracetamol were completely antagonized, resulting in subadditive interactions. The selective antagonist of δ-opioid receptors naltrindole failed to significantly attenuate the combinations of morphine with ketoprofen, meloxicam and piroxicam, but decreased the activity of the combinations of morphine with diclofenac, metamizol and paracetamol, transforming the interactions from supra-additive to additive. Nor-binaltorphimine was used to evaluate the involvement of κ-opioid receptors. Nor-binaltor phimine did not modify the supra-additive interaction of morphine and NSAIDs and the additive interaction of the co-administration of morphine and metamizol. The synergy between morphine and NSAIDs could be related to different pathways of pain transmission, probably related to the different intracellular signal transduction mechanisms of action of opioid and non-opioid agents.Key words: writhing test, NSAIDs, morphine, antinociception, isobolographic analysis, synergy.

Recent advances in clinical use of opioids

Opioid therapy for pain is the subject of numerous randomized clinical trials. Opioids are being developed for delivery by a wide variety of mechanisms. New opioids are becoming available for clinical use. This review surveys recent developments in these clinical trials and provides an overview of what may be expected in the near future for opioid management of pain.

β-Phenylethylamines and the isoquinoline alkaloids

This review covers beta-phenylethylamines and isoquinoline alkaloids derived from them, including further products of oxidation. condensation with formaldehyde and rearrangement, some of which do not contain an isoquinoline system, together with naphthylisoquinoline alkaloids, which have a different biogenetic origin. The occurrence of the alkaloids, with the structures of new bases, together with their reactions, syntheses and biological activities are reported. The literature from July 2002 to June 2003 is reviewed, with 568 references cited.