Lefno Use In Pregnancy & Lactation

Pregnancy: There are no clinical studies evaluating leflunomide in pregnant women, however, A771726 is teratogenic in rats and rabbits, and it may cause fetal harm in humans.
Leflunomide is contraindicated in pregnant women or women of childbearing potential who are not using reliable contraception (see Interactions) during treatment with leflunomide and thereafter as long as the plasma levels of active metabolite, A771726, are above 0.02 mg/l. Pregnancy must be excluded before start of treatment with leflunomide.
Patient must be advised that if there is any delay in onset of menses or any other reason to suspect pregnancy, they must notify the physician immediately for pregnancy testing, and if positive, the physician and patient must discuss the risk to the pregnancy. It is possible that rapidly lowering the blood level of the active metabolite, by instituting the drug elimination procedure described as follows, at the first delay of menses may decrease the risk to the fetus from leflunomide.
For women receiving leflunomide treatment and who wish to become pregnant, one of the following procedures is recommended: After stopping treatment with leflunomide, cholestyramine 8 g is administered 3 times daily for a period of 11 days; After stopping treatment with leflunomide, 50 g of activated charcoal is administered 4 times daily for a period of 11 days.
The 11 days do not need to be consecutive unless there is a need to lower the A771726 plasma level rapidly.
In either case, the A771726 plasma levels <0.02 mg/l must be verified by 2 separate tests at least 14 days apart. Human plasma levels of the active metabolite less than 0.02 mg/l (0.02 μg/ml) are expected to have minimal risk based on available data.
Without the drug elimination procedure, it may take up to 2 years to reach A771726 level <0.02 mg/l, due to individual variation in drug clearance. However, also altera such a waiting period, verification of A771726 levels <0.02 mg/l by 2 separate tests at an interval of at least 14 days is required.
If a waiting period of up to approximately 2 years under reliable contraception is considered unpractical, prophylactic institution of a washout procedure may be advisable.
Reliable contraception with oral contraceptives may not be guaranteed during the washout procedure with cholestyramine or activated charcoal. Use of alternative contraceptive methods is recommended.
Risk of birth defects and other adverse pregnancy outcomes occurring in women who inadvertently became pregnant while taking leflunomide for any length of time in the 1^st trimester of pregnancy are described in Pharmacology: Pharmacodynamics under Actions.
Breast-feeding: Animal studies indicate that leflunomide or its metabolites pass into breast milk. Breast-feeding women must, therefore, not receive leflunomide.