ONCE-A-MONTH INJECTABLE CONTRACEPTIVES - EFFICACY AND REASONS FOR DISCONTINUATION

Reports of the phase III clinical trials on four combined progestogen- estrogen once-a-month injectable contraceptives, Deladroxate, Cyclofem , Mesigyna and Chinese Injectable No. 1, are reviewed focussing on eff icacy and reasons for discontinuation. Deladroxate, currently used in many Latin American countries has proved to be highly effective and we ll accepted. However, this combination was withdrawn by the original m anufacturer because the progestogen component of this drug induced a h igh number of breast cancers in dogs and very curious pituitary hyperp lasia in rats. Cyclofem and Mesigyna were found to be highly effective and highly acceptable drugs. side-effects were minimal and were of mi nor importance. The Chinese Injectable No. I had unacceptably high fai lure rates with a monthly injection schedule. After doubling the dose in the first month of use, the efficacy was satisfactory. It was found that all monthly injectable contraceptives provided better cycle cont rol than the every 3 months depot-medroxyprogesterone acetate, althoug h abnormal bleeding was still the main drug-related complaint and reas on for discontinuation. Missed appointment is another reason for disco ntinuation which might reflect the problem of frequent injection sched ule, thus indicating the need for proper selection of the users and go od counselling.