About 15 percent of adolescent girls report severe menstrual pain. Although dysmenorrhea is the largest cause of time lost from school or work in this population, a small percentage seek medical help. Most adolescents self-treat menstrual pain using non-steroidal anti-inflammatory drugs or other nonprescription agents. Oral contraceptives commonly are used to treat dysmenorrhea in older women, and their effectiveness is supported by a few low-quality clinical trials. Davis and colleagues studied the effectiveness of low-dose oral contraceptives in treating dysmenorrhea in adolescent girls.

The researchers recruited healthy nulliparous girls 19 years or younger who reported moderate to severe menstrual pain. The severity of dysmenorrhea was established using a standardized scale validated in earlier research. Eligible participants had regular menstrual cycles of 21 to 35 days, no gynecologic pathology, and no contraindication to oral contraceptive use. Participants also were required to be sexually abstinent or to use condoms for birth control. Parents gave informed consent for girls younger than 18 years. Baseline assessment included medical history and physical examination plus the collection of detailed information about menstruation and related symptoms using tools such as the Moos Menstrual Distress Questionnaire (MMDQ). Other data included standardized scales to measure stress and depression. The participants were randomly assigned to receive oral contraceptive (ethinyl E2 20 mcg plus 100 mg levonorgestrel) or identical placebo in 28-day blister packs. Patients were telephoned after each menses for two months and questioned about pain and medication use. Participants also completed an exit interview toward the end of the third month of therapy. The primary outcome was a change in the MMDQ pain subscale score. Secondary outcomes included reported use of analgesia and ratings of menstrual-related pain duration, severity, and frequency.

The 38 adolescents assigned to oral contraceptive therapy were comparable with the 38 assigned to placebo in all significant variables. At baseline, 58 percent of participants reported severe dysmenorrhea, 55 percent reported associated nausea, and 39 percent reported missing usual activities at least one day per month because of menstrual pain. By the third cycle of therapy, the mean MMDQ pain score in the treatment group had fallen from 11.1 to 3.1. For those assigned to placebo, the scores fell from 11.8 to 5.8. Analgesic use also fell dramatically in both groups, from more than 16 pills to six pills per menses. In the treatment group, the mean analgesic use in the third cycle was 1.3 pills, significantly less than the 3.7 pills reported by the placebo group. Sixty-one percent of the treatment group reported no medication use by the third cycle, compared with 36 percent of the placebo group. The mean pain ratings were significantly lower in oral contraceptive users than those taking placebo. Measures of the duration and frequency of pain were lower in the treatment group, but the differences did not reach statistical significance. No serious adverse effects were reported or noted during the study. The two discontinuations in the treatment group were attributed to acne and nausea. One participant in the placebo group withdrew because of mood changes.

The authors conclude that a low-dose oral contraceptive is more effective than placebo in managing dysmenorrhea in adolescents. Although the study is relatively small, they recommend consideration of low-dose oral contraceptive therapy for adolescents with severe menstrual-related pain.

editor’s note: Besides the primary result, this study has at least two messages of significance for family physicians. The first is the prevalence and morbidity of dysmenorrhea. Perhaps we regard menstrual cramps as a somewhat trivial concern and do not ask our adolescent patients about the impact on their lives and their openness to therapy. Just asking and advising may be sufficient to initiate enormous benefit, as indicated by the dramatic improvements in symptoms reported by the placebo group. A brief intervention by a skilled family physician could reduce pain scores for this common problem by more than two thirds.—A.D.W.