Drugs in Pregnancy and Lactation: Tenth Edition



PREGNANCY RECOMMENDATION: Limited Human Data—No Relevant Animal Data



Tranylcypromine is a monoamine oxidase inhibitor used in the treatment of major depressive episode without melancholia. Other agents in this subclass are iproniazid, isocarboxazid, nialamide, and phenelzine. Although risk was suggested in consecutive pregnancies from one woman, the human pregnancy experience is too limited to assess adequately the embryo–fetal risk.


Relevant animal reproduction data have not been located. However, the drug crosses the rat placenta (1).

The Collaborative Perinatal Project monitored 21 mother–child pairs exposed to monoamine oxidase inhibitors during the 1st trimester, 13 of whom were exposed to tranylcypromine (2). Three of the 21 infants had malformations (relative risk 2.26). Details of the 13 cases with exposure to tranylcypromine were not specified.

A brief 2000 abstract described two consecutive adverse pregnancy outcomes in a woman treated with tranylcypromine (3). In the first pregnancy, the 41-year-old woman with severe depression was treated with tranylcypromine (100 mg/day), pimozide (1 mg/day), and diazepam (5–10 mg/day). The woman delivered a stillborn fetus at 31 weeks’ gestation. Examination of the macerated female fetus revealed hypertelorism, a large atrioventricular septal defect, single coronary ostium, and right pulmonary isomerism. The placenta had multiple infarcts that were considered significant factors in the fetal death. In her second pregnancy (other drugs and doses not specified), an ultrasound at 19 weeks’ revealed a fetus with a head described as “lemon-shaped.” A female infant (normal karyotype) was delivered at 38 weeks’ because of poor growth (weight not specified). The infant had multiple defects, including hypertelorism, low-set overfolded ears, cleft palate, micrognathia, marked distal phalangeal hypoplasia, agenesis of the corpus callosum, and an atrioventricular septal defect (first detected at 26 weeks’). The outcomes of both pregnancies were attributed to tranylcypromine, possibly due to reduced uterine and placental blood flow (3).

It is not known if tranylcypromine crosses the human placenta. The molecular weight (about 365) is low enough that exposure of the embryo–fetus should be expected.


No reports describing the use of tranylcypromine during lactation have been located. The molecular weight (about 365) is low enough that excretion into breast milk should be expected. The effect of this exposure on a nursing infant is unknown.


1.Product information. Parnate. SmithKline Beecham Pharmaceuticals, 2000.

2.Heinonen OP, Slone D, Shapiro S. Birth Defects and Drugs in Pregnancy. Littleton, MA: Publishing Sciences Group, 1977:336–7.

3.Kennedy DS, Evans N, Wang I, Webster WS. Fetal abnormalities associated with high-dose tranylcypromine in two consecutive pregnancies (abstract). Teratology 2000;61:441.