Impairs immune response to vaccines; possible infection with live vaccines, zidovudine, zalcitabine. May alter action of oral anticoagulants and phenytoin.
Pregnancy category D. There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.
Lactation: Excreted in breast milk, do not nurse
Regular monitoring of uric acid concentrations, blood counts, renal and hepatic function is recommended. Prior irradiation therapy. Elderly. Avoid use of live vaccines.