Reserpine Pregnancy and Breastfeeding Warnings

Reserpine Pregnancy Warnings

Reserpine has been assigned to pregnancy category C by the FDA. Animal studies have revealed evidence of teratogenicity after doses 125 to 250 times the maximum recommended human dose (MRHD, on a per kg basis) were given to rats. Abnormalities included anophthalmia, absence of the axial skeleton, and hydronephrosis. Pregnancy in rabbits was interrupted when doses 10 times the MRHD were given early or late in pregnancy. There are no controlled data in human pregnancy. Reserpine should only be used during pregnancy when there are no alternatives and benefit outweighs risk.

There are three relevant sources of information on the use of reserpine during human pregnancy: a case report and two retrospective studies.

In one case, a stillborn female was born at gestation week 30 to a hypertensive, 30-year-old mother who had taken reserpine from days 13 to 41. Abnormalities included cleft lip and palate and bilateral anophthalmia, marked scoliosis, a thoracolumbar open defect, and diaphragmatic agenesis. The mother had also been exposed to tobacco and ampicillin.

In response to this case report, Cziezel summarized the Hungarian experience with reserpine from 1980 to 1984. During this period, 52 of 6,227 pregnant women were exposed to reserpine. Neither the total group nor subgroups of congenital anomalies indicated a significant increase associated with reserpine treatment during pregnancy. There was no evidence of any congenital reserpine syndrome.

Of 50,282 mother-child pairs monitored by the Collaborative Perinatal Project, 48 had first trimester exposure to reserpine and 475 had exposure to reserpine at anytime during pregnancy. Of the 48, four defects (8%) were observed, which was more than expected. Of the 475, microcephaly (7), hydronephrosis (3), inguinal hernia (12), and hydroureter (3), were observed. None of these anomalies occurred significantly more than expected.

Data from the Michigan Medicaid Birth Defects Study failed to reveal an association between reserpine and congenital abnormalities (written communication, Franz Rosa, MD, Food and Drug Administration, 1994). This was a retrospective study of 229,101 completed pregnancies between 1985 and 1992, of which 15 were exposed to reserpine at some time during the first trimester, and 42 were exposed to the drug at any time during pregnancy. No birth defects were observed. These data do not support an association between reserpine and birth defects, although conclusions from this study have not been made based on the small number of pregnancies with known exposure to the drug.

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