ch12.qxd 8/13/2001 922 3:11 PM D RUG U SE IN Page 922 S PECIAL P OPULATIONS ANTINEOPLASTICS AND IMMUNOSUPPRESSANTS CYTOKINES Interferons An IV dose of 30 million units of interferon alfa-N3 resulted in only a slight increase over physiologic milk levels in one woman.48 DNA INTERCALATING DRUGS Doxorubicin Doxorubicin and its primary active metabolite, doxorubicinol, appear in milk, with their highest milk concentrations occurring 24 hr after a dose Mitoxantrone Measurable levels of mitoxantrone occurred in milk for at least 28 days after mg/kg was given daily for days.49 MITOTIC INHIBITORS Etoposide Etoposide is undetectable in milk 24 hr after a dose.49 MISCELLANEOUS ANTINEOPLASTICS Hydroxyurea Only small amounts of hydroxyurea are found in milk, but breastfeeding is not advised IMMUNOSUPPRESSANTS Three infants reportedly were breastfed safely during maternal azathioprine use (75–100 mg/day) after renal transplantation Low concentrations of the azathioprine metabolite, mercaptopurine, were found in milk Breastfeeding can be undertaken with close infant monitoring for infection or other signs of immunosuppression during azathioprine therapy, although there is concern over potential carcinogenicity.1,12 Maternal cyclosporine therapy results in the infant receiving ≤2% of the mother’s mg/kg dosage.50,51 At least infants have been breastfed safely for 4–12 months during maternal therapy with cyclosporine, prednisone, and azathioprine Infant serum cyclosporine levels were undetectable (