Pregnancy: The active metabolite of leflunomide, A771726 is suspected to cause serious birth defects when administered during pregnancy. Lefno is contraindicated in pregnancy.
Women of childbearing potential have to use effective contraception during and up to 2 years after treatment or up to 11 days after treatment.
For women receiving leflunomide treatment and who wish to become pregnant, one of the following procedures is recommended in order to ascertain that the foetus is not exposed to toxic concentration of A771726 (target concentration below 0.02 mg/l):
Waiting period: A771726 plasma levels can be expected to be above 0.02 mg/l for a prolonged period. The concentration may be expected to decrease below 0.02 mg/l about 2 years after stopping the treatment with leflunomide.
After a 2-year waiting period, the A771726 plasma concentrations is measured for the first time. Thereafter, the A771726 plasma concentrations must be determined again after an interval of at least 14 days. If both plasma concentrations are below 0.02 mg/l no teratogenic risk is to be expected.
Breast feeding: Animal studies indicate that leflunomide or its metabolites pass into breast milk. Breast-feeding women must, therefore, not receive leflunomide.