The optimum regime for the administration of misonidazole and the establishment of multi-centre clinical trials.

The amount of misonidazole which may be given to one patient is limited because of the risk of neurotoxicity. The drug may be given with every treatment of a multi-fraction course of radiotherapy or only with some of the treatments. The number of radiotherapy treatments can be reduced or multiple treatments given after each dose of the drug. Experience in 19 patients given daily doses of misonidazole is reported. This is practical regime to be considered for clinical trials of this hypoxic cell sensitizer.