BENZTROPINE

Fetal Risk Summary

Benztropine is an anticholinergic agent structurally related to atropine (see also Atropine). It also has antihistaminic activity. In a large prospective study, 2,323 patients were exposed to this class of drugs during the 1st trimester, 4 of whom took benztropine (1). A possible association was found in the total group between benztropine and minor malformations.

In a surveillance study of Michigan Medicaid recipients involving 229,101 completed pregnancies conducted between 1985 and 1992, 84 newborns had been exposed to benztropine during the 1st trimester (F. Rosa, personal communication, FDA, 1993). Four (4.8%) major birth defects were observed (three expected), three of which were cardiovascular defects (one expected). No anomalies were observed in five other categories of defects (oral clefts, spina bifida, polydactyly, limb reduction defects, and hypospadias) for which specific data were available. Based on a small number of exposures, a possible association is suggested with cardiovascular defects.

Paralytic ileus has been observed in two newborns exposed to chlorpromazine and benztropine at term (2). In one of these infants, other anticholinergic drugs may have contributed to the effect (see Doxepin). The small left colon syndrome was characterized by decreased intestinal motility, abdominal distention, vomiting, and failure to pass meconium. The condition cleared rapidly in both infants after a Gastrografin enema.

Breast Feeding Summary

No data are available (see Atropine).

References

1. Heinonen OP, Slone D, Shapiro S. Birth Defects and Drugs in Pregnancy. Littleton, MA:Publishing Sciences Group, 1977:346–53.
2. Falterman CG, Richardson CJ. Small left colon syndrome associated with maternal ingestion of psychotropic drugs. J Pediatr 1980;97:308–10.