A method of administering N-substituted benzamides, and their acid addition salts, in particular metoclopramide and its acid addition salts, is disclosed wherein the metoclopramide or acid addition salt is injected intramuscularly in a formulation with a pH of about 5.5 to about 7.0 and at a concentration of at least about 50 mg/ml, to deliver a dose of one to 5 mg/kg.
Methods of killing tumor or cancer cells in human patients using an aryl N-substituted carboxamide having one or more aryl halo or one or more aromatic nitrogens, and/or acid addition salts thereof. The carboxamide may be an N-substituted nicotinamide or an N-substituted benzamide having such features, and may be used directly as a chemotherapeutic agent, or as a sensitizer for radiation or other chemotherapeutic agents. New compositions for such use include N-(2-diethylamino-ethyl)-4-amino-3-chlorobenzamide, N-(2-diethylamino-ethyl) nicotinamide, and their acid addition salts, e.g. hydrochlorides.