Analgesic efficacy of piroxicam in the treatment of postoperative pain

Resolving Issues About Efficacy and Safety of Low-Dose Codeine in Combination Analgesic Drugs: A Systematic Review

INTRODUCTION

The objective of this systematic review is to reflect on assumptions in relation to codeine use in combination with other analgesics.

METHODS

MEDLINE was searched according to the predetermined keywords and criteria. Only English language studies were taken into consideration and the outcome data of the final studies were extracted by two reviewers independently from each other and were checked by the third reviewer. Additionally, the available codeine-related Individual Case Safety Reports (ICSRs) retrieved from EudraVigilance were reviewed.

RESULTS

Sixteen placebo-controlled studies that involved 3378 subjects suffering from acute pain were analyzed for the efficacy of low-dose codeine (≤ 30 mg) combination products. Twelve of them found low-dose codeine combinations more efficient in relieving pain than the assigned comparator. According to 20 randomized clinical trials which included at least one dose of codeine (from 30 to 240 mg daily), the vast majority of reported side-effects were mild or moderate in severity. A total of 20 ICSRs for dependence were identified in the EudraVigilance database with codeine as a suspect drug for the 10-year time period for the European region.

CONCLUSIONS

Low-dose codeine combinations are effective after a single application in treating acute pain. Codeine in doses ≤ 30 mg and higher was considered safe since only mild to moderate side-effects were observed. There is no indication in the available sources which clearly links low doses of codeine to substance use disorder in non-dependent subjects.

Piroxicam

A comprehensive profile of piroxicam including the nomenclatures, formulae, elemental composition, appearance, uses and applications. The methods which were utilized for the preparation of the drug substance and their respective schemes are outlined. The physical characteristics of the drug including the ionization constant, solubility, x-ray powder diffraction pattern, differential scanning calorimetry, thermal behavior and spectroscopic studies are described. The methods which were used for the analysis of the drug substance in bulk drug and/or in pharmaceutical formulations including the compendial, spectrophotometric, electrochemical and the chromatographic methods are reported. The stability, toxicity, pharmacokinetics, bioavailability, drug evaluation, comparison, in addition to compiled reviews on the drug substance are involved. Finally, more than four hundred and fifty references are listed at the end of this profile.

Single dose oral aspirin for acute postoperative pain in adults

BACKGROUND

This review is an update of a previously published review in the Cochrane Database of Systematic Reviews on 'Single dose oral aspirin for acute pain'. Aspirin has been known for many years to be an effective analgesic for many different pain conditions. Although its use as an analgesic is now limited in developed countries, it is widely available, inexpensive, and remains commonly used throughout the world.

OBJECTIVES

To assess the analgesic efficacy and associated adverse events of single dose oral aspirin in acute postoperative pain.

SEARCH METHODS

For the earlier review, we identified randomised trials by searching CENTRAL (The Cochrane Library) (1998, Issue 1), MEDLINE (1966 to March 1998), EMBASE (1980 to January 1998), and the Oxford Pain Relief Database (1950 to 1994). We updated searches of CENTRAL, MEDLINE, and EMBASE to January 2012.

SELECTION CRITERIA

Single oral dose, randomised, double-blind, placebo-controlled trials of aspirin for relief of established moderate to severe postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

We assessed studies for methodological quality and two review authors extracted the data independently. We used summed total pain relief (TOTPAR) over four to six hours to calculate the number of participants achieving at least 50% pain relief. We used these derived results to calculate, with 95% confidence intervals, the relative benefit compared to placebo, and the number needed to treat (NNT) for one participant to experience at least 50% pain relief over four to six hours. We sought numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, as additional measures of efficacy. We collected information on adverse events and withdrawals.

MAIN RESULTS

We included 68 studies in which aspirin was used at doses from 300 mg to 1200 mg, but the vast majority of participants received either 600/650 mg (2409 participants, 64 studies) or 990/1000 mg (380 participants, eight studies). There was only one new study.Studies were overwhelmingly of adequate or good methodological quality. NNTs for at least 50% pain relief over four to six hours were 4.2 (3.9 to 4.8), 3.8 (3.0 to 5.1), and 2.7 (2.0 to 3.8) for 600/650 mg, 900/1000 mg, and 1200 mg respectively, compared with placebo. Type of pain model had no significant impact on the results. Lower doses were not significantly different from placebo. These results do not differ from those of the earlier review.Fewer participants required rescue medication with aspirin than with placebo over four to eight hours postdose, but by 12 hours there was no difference. The number of participants experiencing adverse events was not significantly different from placebo for 600/650 mg aspirin, but for 900/1000 mg the number needed to treat to harm was 7.5 (4.8 to 17). The most commonly reported events were dizziness, drowsiness, gastric irritation, nausea, and vomiting, nearly all of which were of mild to moderate severity.

AUTHORS' CONCLUSIONS

Aspirin is an effective analgesic for acute pain of moderate to severe intensity. High doses are more effective, but are associated with increased adverse events, including drowsiness and gastric irritation. The pain relief achieved with aspirin was very similar milligram for milligram to that seen with paracetamol. There was no change to the conclusions in this update.

Comparison of oral versus sublingual piroxicam during postoperative pain management after lower third molar extraction

In this study, 53 patients received piroxicam, administered orally or sublingually, after undergoing removal of symmetrically positioned lower third molars, during two separate appointments. This study used a randomized, blind, cross-over protocol. Objective and subjective parameters were recorded for comparison of postoperative results for 7 days after surgery. Patients treated with oral or sublingual piroxicam reported low postoperative pain scores. The patients who received piroxicam orally took a similar average amount of analgesic rescue medication compared with patients who received piroxicam sublingually (p>0.05). Patients exhibited similar values for mouth opening measured just before surgery and immediately following suture removal 7 days later (p>0.05), and showed no significant differences between routes of piroxicam administration for swelling control during the second or seventh postoperative days (p>0.05). In summary, pain, trismus and swelling after lower third molar extraction, independent of surgical difficulty, could be controlled by piroxicam 20mg administered orally or sublingually and no significant differences were observed between the route of delivery used in this study.

Single dose oral codeine, as a single agent, for acute postoperative pain in adults

BACKGROUND

Codeine is an opioid metabolised to active analgesic compounds, including morphine. It is widely available by prescription, and combination drugs including low doses of codeine are commonly available without prescription.

OBJECTIVES

To assess the efficacy, the time to onset of analgesia, the time to use of rescue medication and any associated adverse events of single dose oral codeine in acute postoperative pain.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE and PubMed to November 2009.

SELECTION CRITERIA

Single oral dose, randomised, double-blind, placebo-controlled trials of codeine for relief of established moderate to severe postoperative pain in adults.

DATA COLLECTION AND ANALYSIS

Studies were assessed for methodological quality and data independently extracted by two review authors. Summed total pain relief (TOTPAR) or pain intensity difference (SPID) over 4 to 6 hours were used to calculate the number of participants achieving at least 50% pain relief, which were used to calculate, with 95% confidence intervals, the relative benefit compared to placebo, and the number needed to treat (NNT) for one participant to experience at least 50% pain relief over 4 to 6 hours. Numbers using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Data on adverse events and withdrawals were collected.

MAIN RESULTS

Thirty-five studies were included (1223 participants received codeine 60 mg, 27 codeine 90 mg, and 1252 placebo). Combining all types of surgery (33 studies, 2411 participants), codeine 60 mg had an NNT of at least 50% pain relief over 4 to 6 hours of 12 (8.4 to 18) compared with placebo. At least 50% pain relief was achieved by 26% on codeine 60 mg and 17% on placebo.Following dental surgery the NNT was 21 (12 to 96) (15 studies, 1146 participants), and following other types of surgery the NNT was 6.8 (4.6 to 13) (18 studies, 1265 participants). The NNT to prevent use of rescue medication within 4 to 6 hours was 11 (6.3 to 50) (11 studies, 765 participants, mostly non-dental); the mean time to its use was 2.7 hours with codeine and 2.0 hours with placebo. More participants experienced adverse events with codeine 60 mg than placebo; the difference was not significant and none were serious. Two adverse event withdrawals occurred with placebo.

AUTHORS' CONCLUSIONS

Single dose codeine 60 mg provides good analgesia to few individuals, and does not compare favourably with commonly used alternatives such as paracetamol, NSAIDs and their combinations with codeine, especially after dental surgery; the large difference between dental and other surgery was unexpected. Higher doses were not evaluated.

Dexamethasone reduces pain after tonsillectomy in adults

The aim of this study was to assess the effect of a course of dexamethasone on postoperative pain and morbidity after adult tonsillectomy. We report the results of a double-blind, randomized, placebo-controlled trial of 200 adult patients undergoing elective tonsillectomy. Patients were randomized to three groups: one group received the non-steroidal anti-inflammatory drug piroxicam for 8 days postoperatively, one group received dexamethasone for the same period and the third group received both drugs. Patients recorded their pain scores and analgesic requirements daily for 10 days. Patients treated with a combination of piroxicam and dexamethasone recorded consistently lower pain scores than those treated with either drug alone. This difference was statistically significant (P < 0.05) on all days except the day of surgery and the second postoperative day. Patients treated with piroxicam alone had significantly higher analgesic requirements than in either of the other groups. Dexamethasone given in this regime reduces postoperative pain and analgesic requirements after adult tonsillectomy.

Single dose piroxicam for acute postoperative pain

BACKGROUND

Piroxicam is a non-steroidal anti-inflammatory drug (NSAID) with analgesic properties, and is used mainly for treating rheumatic disorders. Some drugs have been directly compared against each other within a trial setting to determine their relative efficacies, whereas other have not. It is possible, however, to compare analgesics indirectly by examining the effectiveness of each drug against placebo when used in similar clinical situations.

OBJECTIVES

To determine the analgesic efficacy and adverse effects of single-dose piroxicam compared with placebo in moderate to severe postoperative pain. To compare the effects of piroxicam with other analgesics.

SEARCH STRATEGY

Published reports were identified from systematic searching of Medline, Biological Abstracts, Embase, The Cochrane Library and the Oxford Pain Relief Database. Additional studies were identified from the reference lists of retrieved reports.

SELECTION CRITERIA

The following inclusion criteria were used: full journal publication, randomised placebo controlled trial, double-blind design, adult patients, postoperative pain of moderate to severe intensity at the baseline assessment, postoperative administration of oral or intramuscular piroxicam.

DATA COLLECTION AND ANALYSIS

Summed pain intensity and pain relief data were extracted and converted into dichotomous information to yield the number of patients obtaining at least 50% pain relief. This was used to calculate estimates of relative benefit and number-needed-to-treat for one patient to obtain at least 50% pain relief. Information was collected on adverse effects and estimates of relative risk and number-needed-to-harm were calculated.

MAIN RESULTS

Three trials (141 patients) compared oral piroxicam 20 mg with placebo and one (15 patients) compared oral piroxicam 40 mg with placebo. For single doses of piroxicam 20 mg and 40 mg the respective numbers-needed-to-treat for at least 50% pain relief were 2.7 (2.1 to 3.8) [95% confidence interval] and 1.9 (1.2 to 4.3) [95% confidence interval] compared with placebo over 4-6 hours in moderate to severe postoperative pain. The reported incidence of adverse effects was no higher with piroxicam (20 mg or 40 mg) than with placebo.

REVIEWER'S CONCLUSIONS

Piroxicam appears to be of similar efficacy to other non-steroidal anti-inflammatory drugs (NSAIDs) and intramuscular morphine 10 mg when used as a single oral dose in the treatment of moderate to severe postoperative pain.

Single dose oral aspirin for acute pain

BACKGROUND

Aspirin has been known to be an effective analgesic for many years and is commonly used throughout the world for many different pain conditions. It is important for both prescribers and patients to have the best possible information about the efficacy and safety of analgesics, and this need is reflected in patient surveys which show that postoperative pain is often poorly managed. We also need to benchmark relative efficacy and safety of current analgesics so that we can compare them with new analgesics.

OBJECTIVES

To quantitatively assess the analgesic efficacy and adverse effects of a single-dose of aspirin in acute pain of moderate to severe intensity.

SEARCH STRATEGY

Randomised trials were identified by searching Medline (1966 to March 1998), Embase (1980 to January 1998), the Cochrane Library (Issue 1,1998) and the Oxford Pain Relief Database (1950 to 1994).

SELECTION CRITERIA

The inclusion criteria used were: full journal publication, postoperative pain or a mixture of postoperative and acute trauma pain, oral administration, adult patients, baseline pain of moderate to severe intensity, double-blind design, and random allocation to treatment groups which compared aspirin with placebo.

DATA COLLECTION AND ANALYSIS

Summed pain relief or pain intensity difference over four to six hours was extracted, and converted into dichotomous information yielding the number of patients with at least 50% pain relief. This was then used to calculate the relative benefit and the number-needed-to-treat (NNT) for one patient to achieve at least 50% pain relief.

MAIN RESULTS

Seventy-two randomised single-dose trials met our inclusion criteria, with 3253 patients given aspirin, and 3297 placebo. Significant benefit of aspirin over placebo was shown for aspirin 600/650 mg, 1000 mg and 1200 mg, NNTs for at least 50% pain relief of 4.4 (4.0 to 4.9), 4.0 (3.2 to 5.4) and 2.4 (1.9 to 3.2) respectively. Single-dose aspirin 600/650 mg produced significantly more drowsiness and gastric irritation than placebo, with a number-needed-to-harm (NNH) of 28 (19 to 52) and 38 (22 to 174) respectively. Type of pain model, pain measurement, sample size, quality of study design, and study duration had no significant impact on the results.

REVIEWER'S CONCLUSIONS

Aspirin is an effective analgesic for acute pain of moderate to severe intensity with a clear dose-response. Drowsiness and gastric irritation were seen as significant adverse effects even though the studies were single-dose. The pain relief achieved with aspirin was very similar milligram for milligram to that seen with paracetamol.

[Information level and pharmacotherapeutic practice of dentists, 1990]

Results of an investigation carried out into a population of 285 dentists in Cordoba City (Cordoba, Argentine) with a view to evaluating their pharmacological knowledge, prescriptive behaviour and proposals for the improvement of drug usage, are described. This study showed that 58.3% of the dentists surveyed get most of their pharmacological and therapeutic information through published material issued by pharmacochemical labs. At the same time, about one-third of the individuals surveyed either did not answer or gave incorrect answers to questions related to the pharmacotherapeutic effects the antimicrobial or anti-inflammatory analgesics of their preference. Although 63.5% of the dentists said that they had taken the essential drug model reference list issued by the social security system into account, many of the drugs selected as preferences were not to be found on it. Regarding anti-microbial or anti-inflammatory analgesic drugs, the brands most frequently prescribed were the more expensive ones, strong 66.5% of the dentists surveyed stated the contrary. Finally, this investigation revealed that five manufacturers together held a concentration of the anti-microbial and anti-inflammatory analgesics prescribed by 83.7% and 82.4% of the dentists consulted respectively.

Piroxicam-induced analgesia: evidence for a central component which is not opioid mediated

Piroxicam is a nonsteroidal anti-inflammatory drug with a potent analgesic effect. In order to establish whether the analgesic action of Piroxicam has a central component, we studied the effect of the drug on the nociceptive orbicularis oculi reflexes evoked by electrical stimulation of the cornea and supraorbital nerve in healthy subjects. Piroxicam significantly suppressed the corneal reflex and R3 component of the blink reflex by 28% (p < 0.05) and 50% (p < 0.01), respectively. This effect was not reversed by the i.v. injection of naloxone. Beta-endorphin levels did not change. Piroxicam administration induces distinct inhibitory changes in nociceptive reflexes, which suggests that the analgesic action of the drug has a central component. The ineffectiveness of naloxone, and the lack of beta-endorphin changes, indicate that this central action is independent of the opioid system; other pain regulatory systems are probably involved.