Clinical pharmacology of bleomycin and cisplatin

Bleomycin (Blenoxane) and cisplatin (Platinol) are two anticancer drugs with activity for head and neck tumors. Introduced into clinical use in the past ten years, bleomycin is used primarily in the chemotherapy of squamous cell carcinomas, lymphomas, and testicular carcinoma, while cisplatin is effective against testicular and ovarian carcinoma, head and neck cancer, bladder cancer, and neuroblastoma. Bleomycin is rapidly excreted renally (T 1/2 beta = 2-4 hr) although enzymatic inactivation also occurs in many tissues. Cisplatin is nonenzymatically converted to highly protein-bound metabolites, which then undergo renal elimination, but total body clearance occurs much more slowly than with bleomycin (T 1/2 beta = 40-50 hr). Both agents have acute and chronic toxicities; the acute toxicities are generally reversible but cause a great deal of patient discomfort, while the chronic toxicities are often irreversible and dose-limiting. For bleomycin, the acute toxicities are mucocutaneous and pyretic, while severe nausea and vomiting represent the major acute toxicities of cisplatin therapy. Cumulative dose-related pulmonary toxicity is the most serious chronic toxicity of bleomycin. The clinical, radiographic, and pathologic presentations are nonspecific, although identification of high-risk patients may be possible with serial pulmonary function tests. Cumulative nephrotoxicity occurs with cisplatin use and its incidence and severity can be reduced by maintaining adequate hydration and diuresis during and following administration of the drug.