The efficacy and safety of aceclofenac versus placebo and naproxen in women with primary dysmenorrhoea.

To determine the analgesic efficacy and safety of a single oral dose of aceclofenac 100 mg and compare that with placebo and naproxen 500 mg in women with primary dysmenorrhoea.In this double-blind, prospective, multicentre, randomised, three-way, crossover study, women were randomly assigned to receive one of six treatment sequences, comprising single oral doses of aceclofenac 100 mg, naproxen 500 mg or placebo, when menstrual pain reached a predetermined level of severity. A single dose of the assigned study medication was taken on three menstrual periods; a different medication was taken on each treatment day. Analgesic efficacy was determined by self-reported analgesia scoring and participants' and investigators' global evaluation of treatment effectiveness. Measurements also included physical examination and adverse events.Total pain relief scores were not statistically significantly different for aceclofenac and naproxen, and both were statistically significantly more effective than placebo (p = 0.019 and 0.002, respectively). This finding was supported by secondary endpoints including sum of pain intensity differences (SPID/8), peak analgesia (peak pain intensity and peak pain relief), and participants' and investigators' overall evaluation of effectiveness. Both aceclofenac and naproxen were well tolerated.Aceclofenac (100 mg) and naproxen (500 mg) effectively treated the pain associated with primary dysmenorrhoea, and both were more effective than placebo at easing menstrual pain assessed by various pain relief criteria.