Objective: The purpose of this article is to discuss the probable ways of interactions between some drugs or remedies and steroid contraceptives. Design: A review article. Setting: OBGYN Clinic of the 1st Faculty of Medicine, Prague, Teaching Hospital Bulovka. Subject: Low dose oral contraceptives are very popular these days. Some drugs and remedies could negatively influence the levels of ethinyl estradiol (EE) and/or progestins and thus increase the possibility of their failure. These drugs mostly implicate as an inducer of the CYP450 system (liver) and as an inducer of P-glycoprotein transport system (transmembrane drug pump in the intestines). We wanted to describe briefly the mechanism and the principles of their impact.

        Key words: oral contraceptives, interaction, drug, hormones, steroids