Anaprox in dysmenorrhea: reduction of pain and intrauterine pressure.

In a double-blind parallel trial, 24 dysmenorrheic women received a single dose of Anaprox (1,100 mg) or placebo. Over the next 2 hours, pain intensity was scored and intrauterine pressure was measured using an immobilized microballoon. At the end of 2 hours, all 11 patients given Anaprox (but only three of the 13 given placebo) experienced complete pain relief (p = 0.0004). The resting intrauterine pressure (IUP) decreased from a mean of 51.4 to 26.8 mm Hg in the Anaprox-treated group, while in the placebo group the mean resting IUP values remained essentially unchanged ( drop from 55.4 to 51.9 mm Hg was observed). This difference between the two treatment groups was statistically significant in favor of Anaprox (p = 0.03). Several patients from each group were given 0.2 mg of ergonovine by intramuscular injection following the 2 hour trial. In both groups, the resting IUP increased within 30 minutes; the corresponding increase in pain intensity was more pronounced, however, in the placebo group. These results support the premise that a decrease in resting IUP is directly linked to the pain-relieving effects of Anaprox.