Metronidazole as a Radiosensitizer

Abstract

To the Editor: Urtasun and his colleagues (N Engl J Med 294:1364–1367, 1976) report that metronidazole may prolong patient survival when given before radiotherapy of supratentorial gliomas. Metronidazole has been shown to be an effective radiosensitizer of hypoxic cells in animal tumors, and the authors attribute their results to radiosensitization. However, metronidazole also has direct toxicity for hypoxic mammalian cells.^{1 , 2} Thus, the authors' results might be due to a direct cytotoxic effect of metronidazole additive to that of radiation. Assessment of survival in a third group of patients receiving the same dose of metronidazole after each dose of radiation . . .