GRANISETRON

Fetal Risk Summary

Granisetron is an antiemetic used for the prevention of nausea and vomiting in patients receiving cancer chemotherapy. The drug is a selective 5-hydroxytryptamine3 (5-HT3) receptor antagonist with little or no affinity for other serotonin receptors (1). No evidence of an effect on plasma prolactin concentrations has been found in clinical studies.

Reproductive studies at doses up to 146 and 96 times, respectively, the recommended human dose (based on body surface area) in pregnant rats and rabbits found no evidence of impaired fertility or harm to the fetus (1). Shepard reviewed three studies conducted in rats and rabbits before and after conception or in the perinatal and postnatal periods that found no adverse fetal effects or drug-related effects on behavior (2).

It is not known whether granisetron crosses the placenta to the fetus. The molecular weight (about 349) is low enough, however, that passage to the fetus should be expected.

No reports describing the use of granisetron during human gestation have been located. Because of the indication for this drug, the opportunity for fetal exposure appears to be minimal.

Breast Feeding Summary

No reports describing the use of granisetron during lactation or measuring the amount of drug in breast milk have been located. The indication for granisetron therapy, however, suggests that the opportunities for use of the drug during lactation are minimal. Because of its low molecular weight (about 349), transfer into breast milk should be expected.

References

1. Product information. Kytril. SmithKline Beecham Pharmaceuticals, 1997.
2. Shepard TH. Catalog of Teratogenic Agents. 8th ed. Baltimore, MD:Johns Hopkins University Press, 1995:204–5.