The use of the leukotriene receptor antagonist montelukast (Singulair) in the management of dysmenorrhea in adolescents.

Purpose: Previous studies have shown an increase in leukotrienes in the uterine tissue as well as in the menstrual flow of adult women with dysmenorrhea. An increase in leukotriene-E4, the major urinary leukotriene, was also reported in adolescent girls with dysmenorrhea, further suggesting a possible involvement of these potent vasoconstrictors and inflammatory mediators in generating dysmenorrhea symptoms. In the present study we examined whether blocking leukotrienes might alleviate symptoms of dysmenorrhea in adolescents.

Methods: Twenty-five adolescents (age 16 +/- 1 years, 4 +/- 1 years post menarche, body mass index 23 +/- 1) with dysmenorrhea participated in a randomized, double blind, crossover study. Thirteen girls received one tablet of montelukast (Singulair, Merck, West Point, PA) 10 mg daily starting on day 21 of the cycle until the last day of the menstrual period for two menstrual cycles, followed by one tablet of placebo (Merck, West Point, PA) daily starting on day 21 of the cycle until the last day of the menstrual period for two additional menstrual cycles. The other 12 girls had a reverse schedule starting with placebo. Participants were instructed to use one or two 200-mg tablets of ibuprofen every 6 h in the event of continuing menstrual symptoms. The Cox Menstrual Symptom Scale was used to assess response to treatment. An intent-to-treat approach was used for data analysis.

Results: Twenty-two girls completed the study. Two girls were noncompliant with the study protocol, and one was withdrawn because of Helicobacter pylori infection. Compared with Cox menstrual score (mean +/- SE) before study (46 +/- 6), there was no significant change in menstrual symptoms during treatment with placebo (Cox score 42 +/- 7) or during treatment with montelukast (Cox score 39 +/- 7), and there was no significant difference between montelukast and placebo treatments as well. Likewise, there was no significant difference between the amount of ibuprofen tablets consumed during the menstrual periods before study (4 +/- 1), while on placebo (3 +/- 1), and while on montelukast (4 +/- 1).

Conclusions: This study does not support the use of montelukast, in the current FDA-approved dose (for asthma) and commencing immediately before the menstrual period, for treatment of dysmenorrhea. It remains to be determined in further studies whether a higher dose or a prolonged daily use of montelukast may alleviate symptoms of dysmenorrhea in adolescents.