Pharmaceutical substance and administration method

PURPOSE: To provide a method for reducing the side actions on extrapyramidal system in the case of administering an N-substituted benzamide, phenothiazine and their acid addition salts, especially metoclopramide or its acid addition salt such as metoclopramide hydrochloride. CONSTITUTION: Metoclopramide or its acid addition salt is intramuscularly injected at about pH 5.5-7.0 and a concentration of about >=50 mg/ml for administering the compound at a rate of 1-5 mg/kg. More generally, the agent is administered in a form containing Na ion and having a pH adjusted to decrease the side actions on extrapyramidal system or in a form essentially free from Na ion.