Anti-depressant action of caesium chloride and its modification of chlorpromazine toxicity in mice.

1. Adult male mice were treated with caesium chloride (1.0 mEq/kg, i.p.) once daily for 54 consecutive days before administration of a single dose or reserpine (2.0 mg/kg) or (+)-amphetamine (1.0 mg/kg). Pretreatment with caesium chloride resulted in potentiation of amphetamine-produced enhancement of motility and in antagonism of reserpine-induced behavioural depression in mice as measured by a locomotor activity test, compared to the respective controls. 2. Chronic administration of caesium chloride (1.0 mEq/kg daily) with gradual dose build-up of chlorpromazine (up to 50 mg kg-1 day-1) counteracted chlorpromazine-produced mortality in mice. 3. The results suggest an antidepressant property of Cs+ and the combined treatment of caesium chloride with chlorpromazine might have a clinical application, i.e. in the management of chlorpromazine-induced adverse reaction.