Lomustine (CCNU) for the treatment of resistant lymphoma in dogs

Forty-three dogs with lymphoma that had relapsed or had failed to achieve c omplete remission to previous chemotherapy were treated with lomustine (1-( 2-chloroethyl)-3-cyclohexyl-1-nitrosourea [CCNU]) at a dosage of 90-100 mg/ m(2) body surface area PO every 3 weeks. Durable complete or partial respon ses occurred in 11 dogs for a median of 86 days. The acutely dose-limiting toxicosis was neutropenia 7 days after administration, resulting in a recom mended dosage of 90 mg/m(2). Cumulative thrombocytopenia occurred in dogs r eceiving continued CCNU treatment, and a dose interval of 3 weeks may be to o shea for continued administration of this drug. Toxicoses evident as feve r or central nervous system signs or renal damage were uncommon or rare. CC NU is effective in the treatment of relapsed lymphoma.