Gestodene. A review of its pharmacology, efficacy and tolerability in combined contraceptive preparations.

The newer progestogens gestodene, desogestrel and norgestimate were developed in an attempt to produce agents with more selective progestational activity that would improve cycle control and minimise metabolic changes and adverse events while effectively preventing pregnancy. In clinical practice, gestodene is combined with ethinylestradiol in monophasic or triphasic combined oral contraceptive preparations. The drug has pharmacokinetic advantages over the other new progestogens in that it is active per se (the others are prodrugs) and has high bioavailability (approximately 100%). The ability of gestodene-containing oral contraceptives to inhibit ovulation is similar to that of preparations containing other progestogens although the required dosage is lower. In common with oral contraceptives containing desogestrel or norgestimate, and in contrast with those containing levonorgestrel, gestodene-containing preparations are associated with neutral or positive changes in lipid and carbohydrate metabolism. The effects of gestodene preparations on coagulation parameters, like those of desogestrel and levonorgestrel, are balanced by changes in the fibrinolytic system. Although the impact of these changes on clinical cardiovascular end-points has not been determined, the altered lipid profile is not likely to have significant clinical relevance because of the predominantly thrombogenic nature of cardiovascular disease in oral contraceptive users. Pregnancy rates and Pearl Indices with gestodene-containing preparations are low and similar to those with preparations containing other progestogens. Most pregnancies are attributable to user failure. Cycle control appears to be better with gestodene preparations than with levonorgestrel preparations, and available data suggest that cycle control may also be better with monophasic gestodene/ethinylestradiol than with monophasic desogestrel- or norgestimate-containing preparations, and better with triphasic gestodene- than with triphasic levonorgestrel- or norgestimate-containing preparations. However, differences between the new progestogen-containing preparations need to be confirmed in further large-scale trials. The most common adverse events with gestodene/ethinylestradiol are headaches and breast tension; the incidence of short term adverse events, including acne, is similar to that with preparations containing other progestogens. Changes in blood pressure and bodyweight are negligible. There are no comparative data on the incidence of cardiovascular events with gestodene-containing and other combined preparations. While the risk of breast cancer appears to be increased with long term combined oral contraceptive use in certain patient subgroups, this risk needs to be balanced against the noncontraceptive benefits of these preparations.(ABSTRACT TRUNCATED AT 400 WORDS)