VOL.: 26 (1981) (p. 47)
Studies in which azathioprine was tested in combination with other agents were inadequate for evaluation.
Azathioprine is embryolethal at doses nontoxic to the mother and can induce a variety of severe teratogenic effects in several animal species. It is mutagenic in bacteria and yeast in vitro and in Drosophila melanogaster and mice in vivo. At high concentrations, the drug is clastogenic to human lymphocytes in vitro.
Use of azathioprine during pregnancy may reduce birth weight significantly. The data were insufficient to evaluate the teratogenic potential of this drug to humans. Azathioprine produces chromosomal abnormalities and increases in sister chromatid exchanges in the peripheral lymphocytes of non-cancer patients. No data were available to evaluate the mutagenic potential of this drug to humans.
There is evidence that azathioprine, often combined with prednisone, is associated with an increased incidence of non-Hodgkin's lymphoma, squamous-cell cancers of the skin, hepato-biliary carcinomas, mesenchymal tumours, and perhaps certain other rare neoplasms. The risk of non-Hodgkin's lymphoma is higher in organ transplant recipients; the presence of the graft may make some contribution to this increased incidence.
For definition of the italicized terms, see Preamble Evaluation.
Subsequent evaluation: Suppl. 7 (1987)
See Also: Toxicological Abbreviations Azathioprine (PIM 053) Azathioprine (IARC Summary & Evaluation, Supplement7, 1987)