This approach, tested in an open-label study, had promising results with no serious interactions between the drugs. Rheumatoid arthritis frequently affects women of child-bearing age. The effect of new drugs for RA on pregnancy outcomes is relevant to both patients and physicians. Leflunomide's mechanism of action and the findings in animal studies that the drug is a potential teratogen have led to great caution. To date, no human studies of pregnancy outcomes after exposure to leflunomide have been published, and there have been very few reports of outcomes after inadvertent exposure during pregnancy.
Animal studies provide the only available information on in utero exposure to leflunomide.
There was also an increased rate of fetal loss, reduced maternal weight, and reduced birth weight of surviving pups. These levels exceed the NOEL in animal models. Women taking leflunomide should use reliable contraception. If such women wish to become pregnant or have conceived while taking the drug, the drug should be discontinued and a drug-elimination procedure begun. To enhance elimination, patients can be treated with either 8 g of cholestyramine three times daily or 50 g of activated charcoal four times daily for 11 days.