The safety and contraceptive efficacy of a 24-day low-dose oral contraceptive regimen containing gestodene 60 microg and ethinylestradiol 15 microg.

OBJECTIVE: The safety and contraceptive efficacy of a new 24-day regimen of an oral contraceptive combination containing gestodene (GTD) 60 microg and ethinylestradiol (EE) 15 microg was evaluated in an open-label, multicenter study.

METHODS: Adult women received GTD 60 microg/EE 15 microg from day 1 to 24 and 4 days of placebo during a 28-day cycle for either 13 or 19 cycles.

RESULTS: Of the 1515 subjects enrolled, 1496 were included in the intent-to-treat analysis. A total of three pregnancies were reported during the 18 194 treatment cycles of the study, yielding a Pearl index of 0.21. Life-table analysis, based on 16 954 cycles, gave an accidental pregnancy rate of 0.0033. The most frequent adverse events were headache (reported in 35% of subjects), absence of bleeding (16%), flu-like syndrome (15%), pharyngitis (15%) and abdominal pain (15%). The most frequent reasons for withdrawal from the study were metrorrhagia, flu syndrome and absence of bleeding. Analyses of withdrawal and intermenstrual bleeding and spotting indicated acceptable cycle control.

CONCLUSIONS: The 24-day GTD 60 microg/EE 15 microg regimen appears to be a well-tolerated and effective method for low-dose oral contraception. The current formulation offers an ultra-low steroidal dosage combined with a reduced pill-free interval to improve contraceptive efficacy.