Oral contraceptives and premenstrual symptoms: comparison of a 21/7 and extended regimen

The purpose of this study was to assess the incidence and severity of premenstrual-type symptoms in patients converted from a 21/7 oral contraceptive (OC) regimen to an extended regimen.

This was a single center prospective analysis of the single item Scott and White (S&W) Mood Scale and the Penn State Daily Symptom Report (DSR17) during a 21/7-day followed by a 168-day extended regimen of an OC containing 3 mg of drosperinone and 30 microg of ethinyl estradiol (DRSP/EE).

Of the 114 patients who began the study, 111 completed the preextension 21/7 phase of the study. There were significant differences in severity in the DSR17 and the S&W mood scale among days of the cycle. (P < .0001) The highest values in both scales occurred during the 7-day hormone free interval (HFI) of the 21/7 cycles (P < .001). Of the 111 patients who completed the 21/7 phase of the study, 102 (92%) completed the 168-day extended regimen. During the extended phase of the study, subjects were divided into 2 groups: those with a 100% increase in symptoms from the first half to the second half of the last 21/7 cycle were labeled as high cyclic variability, whereas those with lesser or no cyclic change were labeled as low cyclic variability. There were 55 (54%) with increased cyclic variability in mood scores peaking during the 7-day HFI. Premenstrual-type symptoms measured by both the S&W mood scale and the DSR17 instrument decreased during the extended DRSP/EE OC regimen (P < .0001) compared with the preceding 21/7 cycle, with the greatest improvement detected in the sixth month of continuous OCs (P < .003). The patient group with greatest cyclic variability during the 21/7 regimen demonstrated the most improvement during the 168-day regimen (P < .0001). The single item S&W mood scale was significantly (P < .05) correlated to each of 17 elements of the DSR17 with Spearman R correlation coefficients of 0.25 to 0.57. The greatest correlation coefficient (Spearman's R = 0.66) is with the sum of all 17 items.

A 168-day extended regimen of DRSP/EE led to a decrease in premenstrual-type symptoms compared with the 21/7-day regimen.