Comparison of meclofenamate sodium with buffered aspirin and placebo in the treatment of postsurgical dental pain

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.

Therapeutic uses of non-steroidal anti-inflammatory drugs in dentistry

The non-steroidal anti-inflammatory drugs (NSAIDs) are among the most widely used classes of drugs for the management of acute and chronic pain in dentistry. Their therapeutic efficacy and toxicity are well-documented and provide evidence that NSAIDs generally provide an acceptable therapeutic ratio of pain relief with fewer adverse effects than the opioid-mild analgesic combination drugs that they have largely replaced for most dental applications. The great many studies done with the oral surgery model of acute pain indicate that a single dose of an NSAID is more effective than combinations of aspirin or acetaminophen plus an opioid, with fewer side-effects, thus making it preferable for ambulatory patients. The combination of an NSAID with an opioid generally results in marginal analgesic activity but with an increased incidence of side-effects, which limits its use to patients in whom the NSAID alone results in inadequate analgesia. The selective COX-2 inhibitors hold promise for clinical efficacy with less toxicity from chronic administration and may prove advantageous for the relief of chronic orofacial pain. The use of repeated doses of NSAIDs for chronic orofacial pain should be re-evaluated in light of a lack of documented efficacy and the potential for serious gastrointestinal and renal toxicity with repeated dosing.

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.

Single dose and multidose analgesic study of ibuprofen and meclofenamate sodium after third molar surgery

The purpose of this study was to compare the analgesic efficacy and safety of meclofenamate sodium with ibuprofen after dental impaction surgery. This study was double-blind and used a unique methodology. Patients (N = 254) were first randomized into the single dose phase of the study that included placebo, meclofenamate 50 mg, meclofenamate 100 mg, ibuprofen 200 mg, and ibuprofen 400 mg, followed by a 7-day multidose phase in which patients in the placebo group were rerandomized into one of the active treatment cells. In the single dose phase, all active treatments were significantly more efficacious than placebo for every summary analgesic measure. A positive dose-response was seen for both active drugs with meclofenamate 100 mg and ibuprofen 400 mg exhibiting the greatest efficacy for pain relief, pain reduction, time to remedication, and overall evaluation. Side effects were reported by 26 patients. They were evenly distributed among treatment groups with headache and drowsiness being the most common. During the multidose phase, there were only small differences in efficacy measures among active treatment groups. However, meclofenamate produced a higher incidence of stomach cramps and diarrhea than did ibuprofen (8.8% and 7.2% versus 0.8% and 0.8%). This study indicates that higher doses of nonsteroidal anti-inflammatory drugs are most effective immediately after surgery and that lower doses of these drugs can be used after the first postoperative day. The side effect profile of nonsteroidal anti-inflammatory analgesics is best observed with the use of a multidose study design.

Double-blind comparison of meclofenamate sodium plus codeine, meclofenamate sodium, codeine, and placebo for relief of pain following surgical removal of third molars

A single-dose, randomized, double-blind, parallel-treatment study was performed in 200 outpatients with acute pain caused by the surgical removal of impacted third molars. Meclofenamate 100 mg plus codeine 60 mg, meclofenamate 50 mg plus codeine 30 mg, meclofenamate 100 mg, codeine 60 mg, and placebo treatment groups were compared for sum of pain intensity differences, peak pain intensity difference, sum of pain relief scores, peak pain relief, number of observations at which pain was half relieved, overall evaluation of effectiveness, and time to remedication with a backup analgesic. Meclofenamate 100 mg plus codeine 60 mg was significantly more effective (P less than .005) than codeine 60 mg for all variables except number of observations at which pain was half relieved. Both meclofenamate-codeine combinations and meclofenamate 100 mg alone were significantly more effective (P less than .005) than placebo for all variables. Eleven adverse experiences were reported in 7 patients (3.5%); the most common was somnolence in 1 patient receiving meclofenamate 100 mg plus codeine 60 mg, in 2 treated with meclofenamate 50 mg plus codeine 30 mg, and in 1 treated with codeine 60 mg.

Comparison of meclofenamate sodium and hydrocortisone for controlling the postsurgical inflammatory response in rats

The effectiveness of meclofenamate sodium and hydrocortisone in alleviation of local postsurgical swelling and leukocytic infiltration was compared at two postsurgical intervals in 60 male Sprague-Dawley rats. Both drugs were effective at 24 hours after surgery. Ten doses of 2 mg meclofenamate sodium administered over a 5-day period were more effective in reducing leukocytic infiltration than six doses of 2 mg hydrocortisone administered over the same period. Neither the hydrocortisone nor the meclofenamate sodium at the dosage used adversely affected osteoid formation.

Analgesic efficacy of meclofenamate sodium in episiotomy pain

Meclofenamate sodium was compared, double-blind, with codeine and placebo for the treatment of acute episiotomy pain. One hundred sixty-eight women with moderate or severe episiotomy pain after normal delivery were assigned randomly to one of four treatment groups: one received meclofenamate sodium 200 mg at dose 1 and 100 mg at doses 2 and 3; one received meclofenamate sodium 100 mg at dose 1 and 50 mg at doses 2 and 3; one received codeine 60 mg at all three doses; and one received placebo at all three doses. Efficacy measurements were evaluated periodically for 6 hours after medication. After the first administration, both doses of meclofenamate sodium were significantly superior to placebo and to codeine from 2-6 hours in pain intensity difference and pain relief. For second and third doses, data were available for too few patients to allow valid analysis and interpretation. Adverse effects occurred in 4 patients in each meclofenamate sodium group, and in 8 in the codeine group and in 6 in the placebo group. The study indicates that single 100- and 200-mg doses of meclofenamate sodium are as safe as, and significantly more effective than, codeine 60 mg or placebo for episiotomy pain.