THIOTEPA

Fetal Risk Summary

Thiotepa is a polyfunctional cytotoxic agent that is related chemically and pharmacologically to nitrogen mustard (see also Mechlorethamine).

The drug impairs fertility and is carcinogenic, mutagenic, and teratogenic in animals (1). Reproduction studies in mice and rats at intraperitoneal doses 1/8th and 1 times, respectively, the maximum recommended human dose based on body surface area (MRHD) revealed teratogenicity in both species. Embryolethality was noted in rabbits at 2 times the MRHD (1).

Thiotepa has been used during the 2nd and 3rd trimesters in one patient without apparent fetal harm (2). Long-term studies of growth and mental development in offspring exposed to antineoplastic agents during the 2nd trimester, the period of neuroblast multiplication, have not been conducted (3).

Occupational exposure of the mother to antineoplastic agents during pregnancy may present a risk to the fetus. A position statement from the National Study Commission on Cytotoxic Exposure and a research article involving some antineoplastic agents are presented in the monograph for cyclophosphamide (see Cyclophosphamide).

Breast Feeding Summary

No reports describing the use of thiotepa during lactation have been located. The molecular weight (about 189) is low enough, however, that excretion into breast milk should be expected. Because of the potential for severe toxicity, including tumors, in a nursing infant, women receiving thiotepa should not breast feed.

References

1. Product information. Thioplex. Immunex, 2000.
2. Gililland J, Weinstein L. The effects of cancer chemotherapeutic agents on the developing fetus. Obstet Gynecol Surv 1983;38:6–13.
3. Dobbing J. Pregnancy and leukaemia. Lancet 1977;1:1155.