Fendosal and aspirin in postpartum uterine pain.

The analgesic efficacy of fendosal, a new nonsteroidal anti-inflammatory agent structurally related to salicylic acid, was compared with that of aspirin and placebo in 100 patients with postpartum uterine pain in a single oral dose, parallel, stratified, randomized, double-blind design. With 650 mg aspirin and with 200 or 400 mg fendosal, but not with 100 mg, analgesic effects, as measured subjectively by mean pain intensity scores, began within 1 hr and had similar time-effect patterns for the first 4 or 5 hr. Thereafter with the 2 higher doses of fendosal analgesia contimued to increase, reaching a peak at 6 hr (p less than 0.05) and persisting beyond 7 hr (p less than 0.01), whereas there was no aspirin analgesia after the fifth hour. With 100 mg fendosal time of onset tended to be delayed 2 hr or more, and duration was short. The most effective treatment (largest mean 7-hr sum of pain intensity difference [SPID] scores) was 400 mg fendosal (p less than 0.01); 200 mg fendosal was rated second (p less than 0.01), 650 mg aspirin, third (p less than 0.05), 100 mg fendosal, fourth, and placebo, fifth. There was no significant side effects. These results demonstrate the efficacy of single doses of fendosal as well as the dose-dependent magnitude and time course of effects on postpartum uterine pain.