Background: Premenstrual symptoms can have a significant negative impact on the quality of a woman's life, and they can occur after ovulation during the luteal phase of the menstrual cycle. Symptoms can range from mild (e.g., breast tenderness, bloating, swelling, pelvic heaviness) to more severe somatic and affective problems. Past treatment strategies for premenstrual symptoms have included oral contraceptives. However, many have adverse effects similar to menstrual symptoms, and studies have shown that they also may increase premenstrual symptoms during the last week of active pills. Two recent developments have regenerated interest in this treatment option. The first is the development of a new progestin, drospirenone, which has antimineralocorticoid activity. It is derived from spironolactone (Aldactone), which has been shown to be effective in treating premenstrual symptoms. An extended regimen for this progestin in combination with ethinyl estradiol (Yasmin) is another option. Coffee and associates evaluated the use of the extended regimen compared with the standard regimen of 21 days of treatment, then seven hormone-free days (21/7), for the treatment of premenstrual symptoms.

The Study: Women who were 18 to 48 years of age were considered for study inclusion. To participate, the women had to be taking a combined estrogen and progestin oral contraceptive for three months and have no contraindications for continuing the hormones. The participants were given 3 mg of drospirenone and 30 mcg of ethinyl estradiol. At the beginning of the study, the women were placed on two cycles of 21 days of active medication and seven days of inactive ingredients. At the end of the two cycles, they were placed on a 168-day extended regimen of the same hormones. During the study, participants also were asked to complete daily symptom scoring reports.

Results: For the 111 women who completed the initial 21/7 cycles, the highest symptom scores occurred during hormone-free days. Of this group, 102 women (92 percent) completed the 168-day extended regimen and were divided into two groups. Those whose symptoms increased 100 percent during the second half of the 21/7 cycles were placed in the high-cyclic variability group, and those who did not experience increased symptoms were places in the low-cyclic variability group. During the extended treatment regimen, both groups had a significant reduction in symptoms compared with the 21/7 regimen. The greatest improvement in symptoms occurred during the fifth and sixth segments of the extended cycle. Women with high-cyclic variability were significantly more likely to have improvement in their symptoms compared with those who had low-cyclic variability.

Conclusion: The use of a 168-day extended regimen of drosperinone in combination with ethinyl estradiol decreased premenstrual symptoms compared with a standard 21/7 regimen. This was particularly true for women who had more premenstrual symptoms during the 21/7 regimen.