[Medicamentous enzyme induction and hormonal contraception. Second communication: effects of phenobarbital and phenylbutazone on hormonal contraception (author's transl)].

The effects of phenobarbital and phenylbutazone on hormonal contraception of clinically intact women were studied for the purpose of obtaining information on consequences of medicamentous enzyme induction. Disorders of bleeding were evaluated from four groups of probands who had received complementary doses of phenobarbital or phenylbutazone along with hormonal contraception, and findings were compared with data obtained from a control group. Occurrence of medicamentous enzyme induction was clinically reflected in an accumulation of functional bleeding disorders, depending on the hormonal contraceptive used as well as on the additionally administered drug. Conclusions were drawn for contraceptive practice.