Leflunomide: new antirheumatic drug. Effect on pregnancy outcomes

I am treating a 34-year-old woman with rheumatoid arthritis. She began taking the new drug leflunomide (Arava) 6 months ago and had good clinical response. She is now planning her first pregnancy. What should she do?

Leflunomide is a new and effective disease-modifying antirheumatic drug. Animal studies have shown an increased rate of malformations and fetal death in various species, but there are no data on pregnancy outcomes in humans treated with leflunomide. Since the drug has a prolonged and unpredictable elimination half-life, it should be stopped during pregnancy. The manufacturer recommends that patients who wish to become pregnant be treated with cholestyramine, which enhances elimination.