Pregnancy during TNFalpha antagonist therapy: beware the rifampin-oral contraceptive interaction. Report of two cases.

We report two cases of pregnancy in patients taking TNFalpha antagonists for chronic inflammatory joint disease. A factor in both pregnancies was the use of rifampin concomitantly with a combined oral contraceptive. Both patients were taking rifampin and isoniazid for tuberculosis prophylaxis in compliance with French recommendations for patients with positive intradermal tuberculin tests who are scheduled to receive biotherapeutic agents. Copyright 2010. Published by Elsevier SAS.