Validating speed of onset as a key component of good analgesic response in acute pain

Comparing pain intensity rating scales in acute postoperative pain: boundary values and category disagreements

Pain intensity assessment scales are important in evaluating postoperative pain and guiding management. Different scales can be used for patients to self-report their pain, but research determining cut points between mild, moderate and severe pain has been limited to studies with < 1500 patients. We examined 13,017 simultaneous acute postoperative pain ratings from 913 patients taken at rest and on activity, between 4 h and 48 h following surgery using both a verbal rating scale (no, mild, moderate or severe pain) and 0-100 mm visual analogue scale. We determined the best cut points on the visual analogue scale between mild and moderate pain as 35 mm, and moderate and severe pain as 80 mm. These remained consistent for pain at rest and on activity, and over time. We also explored the presence of category disagreements, defined as patients verbally describing no or mild pain scored above the mild/moderate cut point on the visual analogue scale, and patients verbally describing moderate or severe pain scored below the mild/moderate cut point on the visual analogue scale. Using 30 and 60 mm cut points, 1533 observations (12%) showed a category disagreement and using 35 and 80 mm cut points, 1632 (13%) showed a category disagreement. Around 1 in 8 simultaneous pain scores implausibly disagreed, possibly resulting in incorrect pain reporting. The reasons are not known but low rates of literacy and numeracy may be contributing factors. Understanding these disagreements between pain scales is important for pain research and medical practice.

Evaluation of Intravenous Infusion of Ibuprofen with Paracetamol-Morphine in Pain and Satisfaction of Patients Undergoing Supratentorial Brain Surgery

Background

The pain experienced following supratentorial brain surgery is usually defined as moderate to severe. Therefore, pain-management approaches, including narcotics, are an integral part of treatment regimens that cause respiratory complications or seizures, and reducing this pain level and increasing patient satisfaction is vital.

Methods

This randomized, double-blind clinical trial study to evaluate the pain level and satisfaction in patients undergoing surgery for supratentorial brain neoplasms was performed on two groups with a sample size of 50 patients. In group I, after removal of the brain lesion (at the beginning of dura closure), 400 mg of ibuprofen solution was infused intravenously over 30 minutes. In group II, morphine 0.07 mg/kg intravenously with 1000 mg paracetamol was infused over 30 minutes. After injecting ibuprofen and paracetamol morphine, the patient's pain level and satisfaction with the process were checked.

Results

Patients' satisfaction score in the first 6 hours in the ibuprofen group was 1.67 ± 0.72, and in the other group was 2.27 ± 0.7, which was statistically different (P-value = 0.029). The mean of VAS in the first, second, third, and fourth hours was not statistically different. In the comparative analysis of the laboratory indicators of platelet function analysis in the two groups, none of the measured items had a significant difference between the two groups in the three measurement periods (P > 0.05).

Conclusions

Administration of ibuprofen led to pain relief and patient satisfaction comparable to morphine and paracetamol, and after the surgery for supratentorial brain tumors, ibuprofen did not affect the patients' blood clotting functions.

Relationship between Pharmacokinetic Profile and Clinical Efficacy Data of Three Different Forms of Locally Applied Flurbiprofen in the Mouth/Throat

This study aimed to link pharmacokinetic (PK) data from different flurbiprofen preparations for the treatment of sore throat with published data to elucidate whether early efficacy is due to the local action of flurbiprofen or a systemic effect after absorption of the swallowed drug. Three comparative bioavailability studies conducted in healthy subjects provided data from flurbiprofen 8.75 mg formulations, including spray solution, spray gel, lozenges, and granules. A parallel interstudy comparison was made of PK parameters, including partial AUCs (pAUCs), using an ANOVA model with the calculation of 90% confidence intervals (CI) for the differences between least squares (LS) means for each of the test groups versus the respective reference groups. All three studies showed bioequivalence for the respective product comparisons. The interstudy comparison showed a slower rate of absorption for granules compared to spray solution (reference) based on T_max, C_max, and pAUCs for 1 h and 2 h. When AUC_0.25h and AUC_0.5h were considered, slower rates of absorption were also seen for lozenges and spray gel. The differences correlated with the reported time of onset of action, which is faster for the spray solution (20 min) compared to lozenges (26 min) and granules (30 min). These pAUCs provide useful data that allow for the discrimination between formulations. Moreover, the pAUC values represent <5% of the total AUC, suggesting that the early onset of pain relief is a response to immediate local absorption at the site of action rather than a systemic effect.

New Insights Into the Pharmacological Management of Postoperative Pain: A Narrative Review

Postoperative pain is prevalent and often undertreated. There is a risk that untreated or suboptimally treated postoperative pain may transition into chronic postoperative pain, which can be challenging to treat. Clinical guidelines recommend the use of multimodal analgesia, including non-steroidal anti-inflammatory drugs (NSAIDs), acetaminophen, and, in some cases, opioids. NSAIDs are a broad class of drugs with different attributes such as cyclo-oxygenase (COX)-1 or COX-2 selectivity, onset of action, and analgesic potency. NSAIDs are associated with gastrointestinal and cardiovascular side effects and should be administered at the lowest effective dose for the shortest effective duration but can be effective in postoperative pain. The role of opioids in postoperative analgesia is long-standing but has recently come under scrutiny. Opioids are often used in multimodal analgesic combinations in such a way as to minimize the total consumption of opioids without sacrificing analgesic benefit. Special clinical considerations are required for surgical patients already on opioid regimens or with opioid use disorder. A particularly useful fixed-dose combination product for postoperative analgesia is dexketoprofen-tramadol, which confers safe and effective postoperative pain control and reduces the risk of persistent postoperative pain.

Efficacy of Different Ibuprofen Formulations with Two Prescription Methods on Post Endodontic Pain of Teeth with Irreversible Pulpitis: A Randomized Clinical Trial

Introduction

Pain management during root canal therapy and after that is of great importance in endodontics. This study aimed to compare the effect of two non-steroidal anti-inflammatory drugs (NSAIDs); ibuprofen and ibuprofen lysine with two methods of prescription on pain after single-visit root canal treatment of first and second mandibular molar teeth with irreversible pulpitis.

Materials and Methods

This randomized study recruited subjects experiencing moderate to severe pain from a tooth diagnosed with symptomatic irreversible pulpitis (n=120). Subjects were randomized to receive 400 mg ibuprofen acid or 400 mg ibuprofen lysine regularly or on demand. The primary objective was to measure changes in pain scores at post-operative time frames of 6, 12, 18, 24, 48 and 72 hours after the root canal treatment on a 0-10 numerical rating scale (NRS). Independent T-test, Non-parametric Kruskal-Wallis Test and Friedman Test were used to analyze the data.

Results

Kruskal-Wallis analysis showed a significant difference in NRS score between on-demand ibuprofen group and regular ibuprofen group and also between regular ibuprofen lysine group and regular ibuprofen group at 6 hours after the treatment (P<0.05). But no remarkable difference was observed in the recorded mean pain intensity of four study groups in the other time frames (P>0.05).

Conclusions

Based on this randomized clinical trial, there was no significant difference in the pain intensity of patients using ibuprofen and ibuprofen lysine. Additionally, there was no significant difference in the degree of pain between the on-demand and regular groups, despite the fact that patients in the on-demand group used less medications. Due to the multiple negative effects of NSAIDs, it would be wise to prescribe ibuprofen on demand.

Comparing ERAS-outpatient versus standard-inpatient hip and knee replacements: a mixed methods study exploring the experience of patients who underwent both

BACKGROUND

Optimizing patients' total hip and knee arthroplasty (THA/TKA) experience is as crucial for providing high quality care as improving safety and clinical effectiveness. Yet, little evidence is available on patient experience in standard-inpatient and enhanced recovery after surgery (ERAS)-outpatient programs. Therefore, this study aimed to gain a more in-depth understanding of the patient experience of ERAS-outpatient programs in comparison to standard-inpatient programs.

METHODS

We conducted a convergent mixed methods study of 48 consecutive patients who experienced both standard-inpatient and ERAS-outpatient THA/TKA contralaterally. A reflective thematic analysis was conducted based on data collected via a questionnaire. Bivariate correlations between the patient experience and patients' characteristics, clinical outcomes and care components satisfaction were performed. Then, the quantitative and qualitative data were integrated together.

RESULTS

The theme Support makes the difference for better and for worse was identified by patients as crucial to their experience in both joint replacement programs. On the other hand, patients identified 3 themes distinguishing their ERAS-outpatient from their standard-inpatient experience: 1) Minimizing inconvenience, 2) Home sweet home and 3) Returning to normal function and activities. Potential optimization expressed by patients were to receive more preoperative information, additional postoperative rehabilitation sessions, and ensuring better coherence of care between hospital and home care teams. Weak to moderate positive and statistically significant correlations were found between patients' THA/TKA experience and satisfaction with pain management, hospital stay, postoperative recovery, home care, and overall results (rs = + [0.36-0.66], p-value < 0.01).

CONCLUSION

Whatever the perioperative program, the key to improving patients' THA/TKA experience lies in improving support throughout the care episode. However, compared to standard-inpatient care, the ERAS-outpatient program improves patients' experience by providing dedicated support in postoperative care, reducing postoperative inconvenience, optimizing pain management, returning home sooner, and recovering and regaining function sooner. Patients' THA/TKA experience could further be enhanced by optimizing the information provided to the patient, the rehabilitation program and the coherence between care teams.

Randomized trial of poloxamer 407-based ropivacaine hydrogel after thoracoscopic pulmonary resection

BACKGROUND

We conducted a comparative study to evaluate the efficacy of poloxamer 407-based ropivacaine hydrogel at the wound site (Gel) and continuous thoracic paravertebral block (On-Q) for postoperative pain following thoracoscopic pulmonary resection.

METHODS

This prospective, randomized, noninferiority study included 89 patients randomized into the two groups; Gel (poloxamer 407-based 0.75% ropivacaine, 22.5 mg) and On-Q (0.2% ropivacaine, 4 mg/hour for 48 hours). The primary outcome measure was total fentanyl consumption and secondary outcome measures were the need for rescue analgesia and pain intensity using the numeric rating scale (NRS).

RESULTS

There was no significant difference in total fentanyl consumption between the Gel group and the On-Q group (1504.29 ± 315.72 mcg vs 1560.32 ± 274.81 mcg, p = 0.374). Pain intensity using the NRS between the Gel group and the On-Q group demonstrated no statistical differences (6 hours: 3.56 vs 3.55, p = 0.958; 24 hours: 3.21 vs 3.00, p = 0.250; 48 hours: 2.75 vs 2.49, p = 0.233; and 72 hours: 2.39 vs 2.33, p = 0.811), and there was no significant difference in the frequency of analgesic rescue medication use (3.70 vs 3.33, p = 0.417).

CONCLUSIONS

We confirm the noninferiority of Gel compared with On-Q for acute postoperative pain following thoracoscopic pulmonary resection. Considering a technical simplicity and low systemic toxicity of the local injection of Gel, this analgesic modality may be worthy of further research and is thus considered to have potential as a viable alternative to On-Q for regional analgesia.

From the pharmaceutical to the clinical: the case for effervescent paracetamol in pain management. A narrative review

OBJECTIVE

Paracetamol has an established place in the management of mild-to-moderate pain, but has certain limitations, including varying bioavailability, and potential hepatotoxicity if taken in overdose. Effervescent formulations may help to overcome these limitations.

METHODS

Pubmed searches, with no limits on date or language, were conducted in February 2020. Further references were identified from the reference lists of retrieved articles, and from the authors' knowledge of the field.

RESULTS

Effervescent formulations contain an organic acid (usually citric acid) and carbonate or bicarbonate salts (usually sodium bicarbonate). Upon contact with water, these react to form carbon dioxide, which facilitates the disintegration of the tablet and dissolution of the active drug. Moreover, sodium bicarbonate dose-dependently increases gastric emptying, which together with rapid dissolution facilitates drug absorption. In pharmacokinetic studies, effervescent formulations result in faster absorption of paracetamol than conventional oral formulations, and this translates into a faster onset of analgesia in clinical trials. Effervescent paracetamol has a favorable safety profile, with good tolerability. Importantly, the sodium content of some preparations does not appear to increase cardiovascular risk under real world conditions. Effervescent formulations may also offer advantages in terms of ease of administration and palatability.

CONCLUSIONS

Effervescent formulations of paracetamol result in faster drug absorption, and hence more rapid analgesia, than oral tablets, and offer a favorable tolerability and safety profile. The use of such formulations may therefore help to promote appropriate use of paracetamol.

A Randomized, Double-Blind, Placebo-Controlled Trial of Ibuprofen Lysinate in Comparison to Ibuprofen Acid for Acute Postoperative Dental Pain

INTRODUCTION

Ibuprofen acid is poorly soluble in the stomach, thus reaching maximum plasma levels at approximately 90 min post-dose. Ibuprofen lysinate has been developed to accelerate absorption of ibuprofen to shorten the time to analgesic efficacy. This study compared analgesic efficacy and onset of effect of a single dose of ibuprofen lysinate or ibuprofen acid in patients undergoing third molar extraction.

METHODS

Randomized, double-blind, placebo-controlled, multi-center, parallel-group single-dose study. Adults (18-60 years) undergoing extraction of ≥ 1 third molar were randomized 2:2:1 to ibuprofen lysinate, ibuprofen acid, or placebo postoperatively. Pain relief (PAR, 5-point scale, 0 = none to 4 = complete pain relief) and pain intensity (PI, 100 mm visual analog scale) were assessed between 15 and 360 min post-dose. The primary endpoint was the weighted sum of PAR scores at 6 h (TOTPAR). Time to onset of effect, global assessment of efficacy, and adverse events were also assessed.

RESULTS

Overall, 351 patients received ibuprofen lysinate (N = 141), ibuprofen acid (N = 139), or placebo (N = 71). Both active treatments significantly reduced pain compared with placebo, from 15 min post-dose to 6 h (TOTPAR: ibuprofen lysinate: 19.57; ibuprofen acid: 19.96; placebo: 8.27). Ibuprofen lysinate was significantly more effective than placebo, but non-inferior to ibuprofen acid, at providing pain relief over 6 h. There was no significant difference between ibuprofen lysinate and ibuprofen acid for onset of analgesia. Both ibuprofen formulations were well tolerated; all adverse events were mild to moderate and considered unrelated to treatment.

CONCLUSIONS

A single dose of ibuprofen lysinate is non-inferior to ibuprofen acid in terms of analgesic efficacy, onset of action, and tolerability in patients who have recently undergone dental surgery.

TRIAL REGISTRATION

EudraCT No. 2006-006942-33. Plain language summary available for this article.

Comparative Bioavailability Study of a New Orodispersible Formulation of Ibuprofen Versus Two Existing Oral Tablet Formulations in Healthy Male and Female Volunteers

PURPOSE

This study aimed to assess the comparative bioavailability between ibuprofen acid orodispersible tablets (Test product) and ibuprofen acid oral tablets (Reference product).

METHODS

This was a randomized, single-dose, 3-way crossover, open-label, pharmacokinetic study in 36 healthy male and female volunteers. Blood samples were taken periodically over a 12-h period after dosing to derive total plasma ibuprofen and S(+)/R(-) ibuprofen enantiomer pharmacokinetic parameters; safety profile and tolerability were evaluated throughout the study.

FINDINGS

After a single-dose administration of ibuprofen acid oral tablets (2 × 200 mg), the total ibuprofen C_max and AUC_0-t (geometric least square [LS] mean) for the Test product was 29.4 μg/mL and 100.6 h/μg/mL, respectively, and for the Reference product it was 30.6 μg/mL and 98.7 h/μg/mL. The geometric LS mean Test/Reference ratio 90% CI for both total ibuprofen C_max (90.71-101.77) and AUC_0-t (98.72-105.23) was contained entirely within the predefined 80.00%-125.00% lower and upper limits; in addition, no statistically significant difference was found in T_max (P = 0.1819) after fasted administration of the Test and Reference products. There were 4 mild treatment emergent adverse events, considered unrelated to the study drug, reported by 2 volunteers during the study; no serious adverse events, no suspected unexpected serious adverse events. and no clinically significant changes in laboratory safety, vital signs, or 12-lead ECG measurements were reported. The enantiomer-specific analysis mirrored that of total ibuprofen, with the C_max and AUC_0-t LS mean Test/Reference ratio 90% CI for both ibuprofen S(+) and R(-) enantiomers contained entirely within the predetermined 80%-125.00% limits.

IMPLICATIONS

This study found that ibuprofen acid 200 mg orodispersible tablets and ibuprofen acid 200 mg tablets met the regulatory criteria for bioequivalence for AUC_0-t and C_max. Post hoc analysis of ibuprofen both S(+) and R(-) enantiomers mirrored the findings for total ibuprofen. All investigational products were found to be well tolerated. Clinicaltrials.gov identifier: NCT03180879.

Food for thought: formulating away the food effect - a PEARRL review

OBJECTIVES

Co-ingestion of oral dosage forms with meals can cause substantial changes in bioavailability relative to the fasted state. Food-mediated effects on bioavailability can have significant consequences in drug development, regulatory and clinical settings. To date, the primary focus of research has focused on the ability to mechanistically understand the causes and predict the occurrence of these effects.

KEY FINDINGS

The current review describes the mechanisms underpinning the occurrence of food effects, sheds new insights on the relative frequency for newly licensed medicines and describes the various methods by which they can be overcome. Analysis of oral medicines licensed by either the EMA or FDA since 2010 revealed that over 40% display significant food effects. Due to altered bioavailability, these medicines are often required to be dosed, rather restrictively, in either the fed or the fasted state, which can hinder clinical usefulness.

SUMMARY

There are clinical and commercial advantages to predicting the presence of food effects early in the drug development process, in order to mitigate this risk of variable food effect bioavailability. Formulation approaches aimed at reducing variable food-dependent bioavailability, through the use of bio-enabling formulations, are an essential tool in addressing this challenge and the latest state of the art in this field are summarised here.

Gender and arch effects on the use of non-opioid analgesics for post endodontic pain reduction

This study aimed to evaluate the secondary outcomes of gender and arch and their impact on pain reduction following initial endodontic therapy. 185 medications, including placebo were prepared, and 170 participants completed the trial. Group 1, received a single dose of Paracetamol alone (G-1), Group 2 received combined Ibuprofen/Paracetamol (G-2). Group 3 received combined Mefenamic acid/Paracetamol (G-3), group 4 received combined Diclofenac K/Paracetamol (G-4) and Group 5 received a placebo (G-5). There were no statistically significant differences in pain reduction between males and females whilst there were statistically significant differences between them and the placebo group. All combinations of Paracetamol performed better in pain reduction than the placebo among females, while there were no statistically significant differences among males. In conclusion, there were no differences in pain reduction between males and females, and arch for the tested analgesics taken immediately following initial endodontic therapy in teeth with irreversible pulpitis.

A Randomized Clinical Trial Comparing 2 Ibuprofen Formulations in Patients with Acute Odontogenic Pain

INTRODUCTION

Ibuprofen sodium dihydrate, a new formulation of ibuprofen, was introduced with the claim of faster onset of analgesia. Most of the data on this new ibuprofen formulation are drawn from studies using the oral surgery model. Because this model differs significantly from the endodontic pain model, we conducted a study comparing ibuprofen sodium dihydrate with conventional ibuprofen acid in endodontic pain patients.

METHODS

This randomized, double-masked study recruited subjects experiencing moderate to severe pain from a tooth diagnosed with symptomatic irreversible pulpitis and symptomatic apical periodontitis (n = 41). Subjects were randomized to receive 400 mg ibuprofen acid (Advil; Pfizer, Madison, NJ) or an equivalent dose of 512 mg ibuprofen sodium dihydrate (Advil Sodium, Pfizer). The outcome measures were time to onset of 50% pain relief recorded using a stopwatch, reduction in spontaneous pain experienced on a 100-mm visual analog scale, and change in mechanical allodynia measured using a bite force transducer. The last 2 measures were obtained before and 60 minutes after administration of the drug.

RESULTS

The median time to onset of 50% pain relief after administration of ibuprofen sodium dihydrate was significantly faster compared with ibuprofen acid (26.5 vs 44 minutes, P = .08). Ibuprofen sodium dihydrate provided a greater reduction in spontaneous pain (50.8% vs 33.3%, P < .05) and mechanical allodynia (15% vs 9%, P > .05).

CONCLUSIONS

In endodontic pain patients, a single dose of ibuprofen sodium dihydrate provides faster onset of pain relief and a greater reduction in spontaneous and evoked pain compared with ibuprofen acid.

Intravenous morphine titration as a rapid and efficient analgesia for adult patients with femoral shaft fractures after injury

This study aimed to compare the analgesic effects of intravenous ibuprofen and intravenous morphine titration for femoral shaft fractures in adult patients. In total, 293 participants were enrolled and randomly received intravenous ibuprofen or intravenous morphine titration. Their visual analogue scale (VAS) results were recorded every 5 minutes after the first administration. The VAS scores before and during transport were also measured. Meanwhile, the type and frequency of the adverse effects were also recorded in both groups. Patients treated with morphine showed a faster and greater reduction in the VAS than those in the ibuprofen group within 1 hour after the first administration. Interestingly, intravenous morphine titration provided consistent analgesia even during the further transport. No significant immediate adverse event was observed in all of the participants, except for sedation, which might be beneficial for keeping the patient quiet and might not be arbitrarily attributed to adverse effects. No addiction was noted in the morphine group. This study demonstrated that intravenous morphine titration is a faster and more efficient analgesia for femoral shaft fractures than ibuprofen in adult patients immediately after injury.

High correlation of VAS pain scores after 2 and 6 weeks of treatment with VAS pain scores at 12 weeks in randomised controlled trials in rheumatoid arthritis and osteoarthritis: meta-analysis and implications

Background

Researchers in clinical trials in rheumatoid arthritis (RA) and osteoarthritis (OA) often measure pain levels with a visual analogue scale (VAS). Of interest to clinical practice and future clinical trial design are associations of change from baseline (CFB) between time points with predictive ability of earlier response for long-term treatment benefit. We assessed the association and predictive ability of CFB in VAS pain between 2, 6 and 12 weeks in randomised controlled trials (RCTs) of non-steroidal anti-inflammatory drugs (NSAIDs).

Methods

Aggregated VAS pain data at baseline and CFB at 2, 6 and 12 weeks were collected from a systematic literature review of 176 RCTs in OA and RA. The predictive ability of earlier assessments for longer-term pain reduction was estimated using correlation and regression analyses. Analysis was performed using the R software package for statistical programming, version 3.1.1.

Results

Appropriate data were available from 50 RCTs (22,854 patients). Correlations between time points were high (weighted correlation coefficients between 2 and 6 weeks, 0.84; between 2 and 12 weeks, 0.79; and between 6 and 12 weeks, 0.96). CFB at 6 weeks was highly predictive and close to CFB at 12 weeks (regression coefficient 0.9, 95 % confidence interval 0.9–1.0). CFB at 2 weeks was significantly associated with CFB at 12 (0.8, 0.7–0.8) and 6 weeks (0.9, 0.8–1.0).

Conclusions

The results showed that early analgesic response measured by VAS for pain beyond 2 weeks of treatment with a particular NSAID is likely to be predictive of response at 12 weeks. Failure to achieve desired pain relief in OA and RA after 2 weeks should trigger reassessment of dosage and/or analgesic.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-0972-7) contains supplementary material, which is available to authorized users.

Dexketoprofen/tramadol 25 mg/75 mg: randomised double-blind trial in moderate-to-severe acute pain after abdominal hysterectomy

BACKGROUND

Dexketoprofen trometamol plus tramadol hydrochloride is a new oral combination of two analgesics, which have different mechanisms of action for the treatment of moderate to severe acute pain.

METHODS

Randomised, double-blind, parallel, placebo and active-controlled, single and multiple-dose study to evaluate the analgesic efficacy and safety of dexketoprofen/tramadol 25 mg/75 mg in comparison with the single agents (dexketoprofen 25 mg and tramadol 100 mg) in moderate to severe acute pain after abdominal hysterectomy. Patients received seven consecutive doses of study drug within a 3-day period, each dose separated by an 8-hour interval. A placebo arm was included during the single-dose phase to validate the pain model. Efficacy assessments included pain intensity, pain relief, patient global evaluation and use of rescue medication. The primary endpoint was the mean sum of pain intensity differences over the first 8 h (SPID8).

RESULTS

The efficacy analysis included 606 patients, with a mean age of 48 years (range 25-73). The study results confirmed the superiority of the combination over the single agents in terms of the primary endpoint (p <0.001). Secondary endpoints were generally supportive of the superiority of the combination for both single and multiple doses. Most common adverse drug reactions (ADRs) were nausea (4.6%) and vomiting (2.3%). All other ADRs were experienced by less than 2% of patients.

CONCLUSIONS

The study results provided robust evidence of the superiority of dexketoprofen/tramadol 25 mg/75 mg over the single components in the management of moderate to severe acute pain, as confirmed by the single-dose efficacy, repeated-dose sustained effect and good safety profile observed.

TRIAL REGISTRATION

EU Clinical Trials Register (EudraCT number 2012-004545-32, registered 04 October 2012); Clinicaltrials.gov ( NCT01904149, registered 17 July 2013).

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.

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.

Ibuprofen for acute treatment of episodic tension-type headache in adults

BACKGROUND

Tension-type headache (TTH) affects about one person in five worldwide. It is divided into infrequent episodic TTH (fewer than one headache per month), frequent episodic TTH (1 to 14 headaches per month), and chronic TTH (15 headaches a month or more). Ibuprofen is one of a number of analgesics suggested for acute treatment of headaches in frequent episodic TTH.

OBJECTIVES

To assess the efficacy and safety of oral ibuprofen for treatment of acute episodic TTH in adults.

SEARCH METHODS

We searched CENTRAL (The Cochrane Library), MEDLINE, EMBASE, and our own in-house database to January 2015. We sought unpublished studies by asking personal contacts and searching on-line clinical trial registers and manufacturers' websites.

SELECTION CRITERIA

We included randomised, placebo-controlled studies (parallel-group or cross-over) using oral ibuprofen for symptomatic relief of an acute episode of TTH. Studies had to be prospective and include at least 10 participants per treatment arm.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, and extracted data. Numbers of participants achieving each outcome were used to calculate risk ratio (RR) and number needed to treat for an additional beneficial outcome (NNT) or number needed to treat for an additional harmful outcome (NNH) of oral ibuprofen compared to placebo for a range of outcomes, predominantly those recommended by the International Headache Society (IHS).

MAIN RESULTS

We included 12 studies, all of which enrolled adult participants with frequent episodic TTH. Nine used the IHS diagnostic criteria, but two used the older classification of the Ad Hoc Committee, and one did not describe diagnostic criteria but excluded participants with migraines. While 3094 people with TTH participated in these studies, the numbers available for any form of analysis were lower than this; placebo was taken by 733, standard ibuprofen 200 mg by 127, standard ibuprofen 400 mg by 892, and fast-acting ibuprofen 400 mg by 230. Participants had moderate or severe pain at the start of treatment. Other participants were either in studies not reporting outcomes we could analyse, or were given one of several active comparators in single studies.For the IHS-preferred outcome of being pain free at 2 hours the NNT for ibuprofen 400 mg (all formulations) compared with placebo was 14 (95% confidence interval (CI), 8.4 to 47) in four studies, with no significant difference from placebo at 1 hour (moderate quality evidence). The NNT was 5.9 (4.2 to 9.5) for the global evaluation of 'very good' or 'excellent' in three studies (moderate quality evidence). No study reported the number of participants experiencing no worse than mild pain at 1 or 2 hours. The use of rescue medication was lower with ibuprofen 400 mg than with placebo, with the number needed to treat to prevent one event (NNTp) of 8.9 (5.6 to 21) in two studies (low quality evidence).Adverse events were not different between ibuprofen 400 mg and placebo; RR 1.1 (0.64 to 1.7) (high-quality evidence). No serious adverse events were reported.

AUTHORS' CONCLUSIONS

Ibuprofen 400 mg provides an important benefit in terms of being pain free at 2 hours for a small number of people with frequent episodic tension-type headache who have an acute headache with moderate or severe initial pain. There is no information about the lesser benefit of no worse than mild pain at 2 hours.

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

BACKGROUND

There is good evidence that combining two different analgesics in fixed doses in a single tablet can provide better pain relief in acute pain and headache than either drug alone, and that the drug-specific benefits are essentially additive. This appears to be broadly true in postoperative pain and migraine headache across a range of different drug combinations, and when tested in the same and different trials. Adding caffeine to analgesics also increases the number of people obtaining good pain relief. Combinations of ibuprofen and caffeine are available without prescription in some parts of the world.

OBJECTIVES

To assess the analgesic efficacy and adverse effects of a single oral dose of ibuprofen plus caffeine for moderate to severe 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), MEDLINE, EMBASE, the Oxford Pain Relief Database, two clinical trial registries, and the reference lists of articles. The date of the most recent search was 1 February 2015.

SELECTION CRITERIA

Randomised, double-blind, placebo- or active-controlled clinical trials of single dose oral ibuprofen plus caffeine for acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently considered trials for inclusion in the review, assessed risk of bias, and extracted data. We used the area under the pain relief versus time curve to derive the proportion of participants with at least 50% pain relief over six hours prescribed either ibuprofen plus caffeine or placebo. We calculated the risk ratio (RR) and number needed to treat to benefit (NNT). We used information on the 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 effects.

MAIN RESULTS

We identified five randomised, double-blind studies with 1501 participants, but only four had been published and had relevant outcome data. These four studies were of high quality, although two of the studies were small.Both ibuprofen 200 mg + caffeine 100 mg and ibuprofen 100 mg + caffeine 100 mg produced significantly more participants than placebo who achieved at least 50% of maximum pain relief over six hours, and both doses significantly reduced remedication rates (moderate quality evidence). For at least 50% of maximum pain relief, the NNT was 2.1 (95% confidence interval 1.8 to 2.5) for ibuprofen 200 mg + caffeine 100 mg (four studies, 334 participants) and 2.4 (1.9 to 3.1) for ibuprofen 100 mg + caffeine 100 mg (two studies, 200 participants) (moderate quality evidence). These values were close to those predicted by published models for combination analgesics in acute pain, and were supported by low (good) NNT values for prevention of remedication.Adverse event rates were low, and no sensible analysis was possible.

AUTHORS' CONCLUSIONS

For ibuprofen 200 mg + caffeine 100 mg particularly, the low NNT value is among the lowest (best) values for analgesics in this pain model. The combination is not commonly available, but can be probably be achieved by taking a single 200 mg ibuprofen tablet with a cup of modestly strong coffee or caffeine tablets. In principle, this can deliver good analgesia at lower doses of ibuprofen.

Single dose oral diclofenac for acute postoperative pain in adults

BACKGROUND

Diclofenac is a nonsteroidal anti-inflammatory drug, available as a potassium salt (immediate release) or sodium salt (enteric coated to suppress dissolution in the stomach). This review updates an earlier review published in the Cochrane Database of Systematic Reviews (Issue 2, 2009) entitled 'Single dose oral diclofenac for acute postoperative pain in adults'.

OBJECTIVES

To assess the analgesic efficacy and adverse effects of a single oral dose of diclofenac for moderate to severe 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), MEDLINE, EMBASE, the Oxford Pain Relief Database, two clinical trial registries, and the reference lists of articles. The date of the most recent search was 9 March 2015.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled clinical trials of single dose, oral diclofenac (sodium or potassium) for acute postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently considered studies for inclusion in the review, assessed risk of bias, and extracted data. We used the area under the pain relief versus time curve to derive the proportion of participants with at least 50% pain relief over six hours prescribed either diclofenac or placebo. We calculated the risk ratio (RR) and number needed to treat to benefit (NNT). We used information on the 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 effects.

MAIN RESULTS

This update included three new studies, providing a 26% increase in participants in comparisons between diclofenac and placebo. We included 18 studies involving 3714 participants, 1902 treated with diclofenac and 1007 with placebo. This update has also changed the focus of the review, examining the effects of formulation in more detail than previously. This is a result of increased understanding of the importance of speed of onset in determining analgesic efficacy in acute pain.The largest body of information, for diclofenac potassium 50 mg, in seven studies, produced an NNT for at least 50% of maximum pain relief compared with placebo of 2.1 (95% confidence interval (CI) 1.9 to 2.5) (high quality evidence). There was a graded improvement in efficacy as doses rose from 25 mg to 100 mg, both for participants achieving at least 50% maximum pain relief, and for remedication within 6 to 8 hours. Fast-acting formulations (dispersible products, solutions, and softgel formulations) had a similar efficacy for a 50 mg dose, with an NNT of 2.4 (2.0 to 3.0). Diclofenac sodium in a small number of studies produced a lesser effect, with an NNT of 6.6 (4.1 to 17) for the 50 mg dose.Adverse event rates were low in these single dose studies, with no difference between diclofenac and placebo (moderate quality evidence).

AUTHORS' CONCLUSIONS

Diclofenac potassium provides good pain relief at 25 mg, 50 mg, and 100 mg doses. Diclofenac sodium has limited efficacy and should probably not be used in acute pain.

Effects of food on pharmacokinetics of immediate release oral formulations of aspirin, dipyrone, paracetamol and NSAIDs - a systematic review

Aims

It is common to advise that analgesics, and especially non-steroidal anti-inflammatory drugs (NSAIDs), be taken with food to reduce unwanted gastrointestinal adverse effects. The efficacy of single dose analgesics depends on producing high, early, plasma concentrations; food may interfere with this. This review sought evidence from single dose pharmacokinetic studies on the extent and timing of peak plasma concentrations of analgesic drugs in the fed and fasting states.

Methods

A systematic review of comparisons of oral analgesics in fed and fasting states published to October 2014 reporting kinetic parameters of bioavailability, time to maximum plasma concentration (t_max), and its extent (C_max) was conducted. Delayed-release formulations were not included.

Results

Bioavailability was not different between fasted and fed states. Food typically delayed absorption for all drugs where the fasting t_max was less than 4 h. For the common analgesics (aspirin, diclofenac, ibuprofen, paracetamol) fed t_max was 1.30 to 2.80 times longer than fasted t_max. C_max was typically reduced, with greater reduction seen with more rapid absorption (fed C_max only 44–85% of the fasted C_max for aspirin, diclofenac, ibuprofen and paracetamol).

Conclusion

There is evidence that high, early plasma concentrations produces better early pain relief, better overall pain relief, longer lasting pain relief and lower rates of remedication. Taking analgesics with food may make them less effective, resulting in greater population exposure. It may be time to rethink research priorities and advice to professionals, patients and the public.

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.