Analgesic effect of aspirin, mefenamic acid and their combination in post-operative oral surgery pain. Randomized controlled trial of mefenamic acid vs paracervical block for relief of pain for outpatient uterine curettage.
A double-blind randomized single dose study of the analgesic effects of 650 mg aspirin, 250 mg mefenamic acid, the combination of 650 mg aspirin and 250 mg mefenamic acid and placebo on 120 patients with pain following oral surgery was conducted. Patients evaluated their pain intensity and extent of pain relief at 1, 2, 3 and 4 h after drug administration. For most parameters, including the sum of the pain intensity differences and the sum of the hourly pain relief scores, each of the drugs was more effective than placebo. Aspirin-mefenamic acid in combination was more effective than both drugs alone, and aspirin and mefenamic acid alone were equally effective for most of the analgesic variables. To compare the efficacy of mefenamic acid vs paracervical block for pain relief during and after fractional curettage.
                Between January 1 and July 31, 2002, the authors enrolled 87 patients with abnormal uterine bleeding, who requested fractional curettage at the Outpatient Gynecologic Clinic, Srinagarind Hospital, Khon Kaen University. A simple randomization procedure was used to distribute the patients into a control group comprising 44 patients given a paracervical block and a treatment group comprising 43 patients given mefenamic acid (500 mg) 2 hours before starting the procedure.
                Pain was scored using a visual analogue scale (VAS range, 0 to 10).
                The median pain scores of the treatment types during endocervical, endometrial, immediately after, and 30 minutes after, fractional curettage were 2.5 vs 3.0 (p = 0.42), 6.5 vs 7.5 (p = 0.19), 4.0 vs 3.5 (p = 0.20) and 1.5 vs 1.0 (p = 0.17), respectively. The rate of complications was 6.8% (3 in 44) in the paracervical lignocaine injection group.
                The efficacy of pain relief for fractional curettage using oral mefenamic acid (500 mg) two hours before the procedure was not statistically different from the paracervical block, but there were fewer side effects. Mefenamic acid should be considered an alternate pain relief during fractional curettage.
Oral mefenamic acid 500 mg was effective at treating moderate to severe acute postoperative pain, based on limited data. Efficacy of other doses, and safety and tolerability could not be assessed.