Pregnancy course and neonatal outcome after exposure to leflunomide--2 cases report and review of literature.

Leflunomide (LMF) is an immunemodulatory drug used in the therapy of Rheumatoid Arthritis (RA). After oral administration in the mucosa of digestive tract LMF is quickly converted to an active metabolite A77126 which is a competitive inhibitor of dihydroorotate dehydrogenase--enzyme required in pirymidyne synthesis resulting in decreased proliferation of T and B lymphocytes. As animal studies showed A77126 embryo- and fetotoxity and no relevant epidemiological research in humans were available, LMF received category X pregnancy destination. This is a detailed presentation of two pregnancy cases during LMF therapy in Poland. The first patient was a multiparous woman suffering from RA for 17 years and treated with LM during the last 16 months. The second woman was a primigravida with RA diagnosed 4 years ago and treated with LMF for the last 20 months. LMF wash-out procedures were started immediately as the patients referred with diagnosed early pregnancies with oral administration of 8g of cholestyramine tid for 11 days. After completing the procedure the patients were referred to the Gynecology and Obstetrics Department. The first pregnancy successfully finished with a vaginal delivery of a completely healthy, female newborn of 2540g at the 41st gestational week and the second patient also delivered vaginally a healthy female newborn of 3200g at 39th week of pregnancy.