Meptazinol and Morphine in Postoperative Pain Assessed with a New Method for Onset and Duration

Abstract

Meptazinol, m-(3-ethyl-1-methyl-hexahydro-1-H-azepin-3-yl) phenol hydrochloride is a centrally active opioid analgesic with a specificity for the mu-1 receptor. It has been reported to lack many of the side effects commonly observed with morphine and morphinelike drugs in man. The objective of this study was to assess the analgesic efficacy and safety of meptazinol (50 mg and 100 mg) relative to morphine (5 mg and 10 mg) when administered intramuscularly for the treatment of postoperative pain. In addition, a new clinical method for measuring onset and duration and a statistical technique for evaluating the study data are presented. One hundred and seventeen patients were evaluated for 6 hours in a randomized double blind, single dose, parallel-groups trial. Estimates of relative potency for hourly pain and relief parameters, and the summary variables sum of pain intensity differences (SPID) and total pain relief (TOTPAR) were performed. The estimate of relative potency of meptazinol to morphine for pain relief was 0.19 at 1/2 hour (i.e. 100 mg of meptazinol was approximately equivalent to 20 mg of morphine). Thereafter, there was a rapid decline of efficacy for meptazinol, with a relative potency estimate of 0.12 at 1 hour and 0.06 at 2 hours. The distribution functions for several time related events were estimated including time to onset, duration and time to remedication. The two drugs had approximately equal onset, but meptazinol had significantly shorter duration. More patients on meptazinol required remedication with a rescue analgesic and at an earlier time than patients on morphine.(ABSTRACT TRUNCATED AT 250 WORDS)

A Controlled Comparative Study of Ibuprofen Arginate versus Conventional Ibuprofen in the Treatment of Postoperative Dental Pain

“…Stringent criteria such as "a lot" of relief or "complete" relief appeared inappropriate for studies in some pain models, such as dental surgery, where barely 50% of patients ever reach "pain half gone" after receiving 650 mg of aspirin. Therefore, we concurred with Siegel et al 18 in viewing intermediate levels of relief, attainable by most patients treated with OTC analgesics, as most fitting. Of the most commonly used pain relief descriptors-none, a little, some, a lot, or complete relief-"some" fits this description, as does the standard question, "Is your pain half gone?"…”

“…Others advocate an intermediate level of relief, such as "some" relief or "pain half gone," while another group supports a higher standard (as is frequently used in headache clinical trials) of nearly "complete relief." Preliminary observations 18 suggested that minimal criteria such as "first perceptible," "any," or "slight" relief provide little separation between known analgesics and placebo because most patients report this change quickly after a dose of study medication. Stringent criteria such as "a lot" of relief or "complete" relief appeared inappropriate for studies in some pain models, such as dental surgery, where barely 50% of patients ever reach "pain half gone" after receiving 650 mg of aspirin.…”

Onset of acetaminophen analgesia: comparison of oral and intravenous routes after third molar surgery

“…The primary efficacy variable was time to analgesia onset measured by the double-click stopwatch method developed by Siegel and colleagues. 12 This method is used to record the onset of analgesia objectively. It distinguishes between a sensation of perceptible pain relief (PPR) and the experience of meaningful pain relief (MPR) by recording the first onset of each with a different stopwatch.…”

Ibuprofen blood plasma levels and onset of analgesia

“…Moreover, studies often present conflicting results; some show a strong correlation between ibuprofen plasma concentrations and analgesia (15,24), whereas others show no correlation (27). Attempts to correlate analgesic efficacy with pharmacokinetic parameters are made difficult by the plethora of efficacy endpoints that have been used in studies (Table 1) (25,28–31).…”