Drug Interaction Study Guide for Contraceptives
FDA has issued a draft guidance entitled Clinical Drug Interaction Studies With Combined Oral Contraceptives. The document is intended to assist sponsors during drug development in evaluating the need for and design of drug-drug interaction (DDI) studies involving combined oral contraceptives (COCs). It discusses when drug developers should conduct DDI studies with COCs and provides recommendations on the design and conduct of DDI studies. The guidance also discusses interpreting and communicating the results and recommendations from these studies.
FDA says the guidance focuses solely on specific recommendations relevant to metabolism-based drug interactions with COCs. Other mechanisms that can cause an interaction (e.g., absorption-based) are not addressed in the guidance but should be considered by sponsors and investigators. In addition, it does not discuss DDIs with progestin-only pills and contraceptives administered via non-oral routes (e.g., transdermal systems). “However, a DDI study with a COC could inform the impact of other types of contraceptives containing the same progestin,” it says.