51. Metoclopramide potentiates d-amphetamine-induced hypermotility and stereotypy in rat.
- Author
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Howard JL, Pollard GT, Craft RM, and Rohrbach KW
- Subjects
- Animals, Drug Synergism, Male, Rats, Rats, Inbred Strains, Time Factors, Dextroamphetamine pharmacology, Metoclopramide pharmacology, Motor Activity drug effects, Stereotyped Behavior drug effects
- Abstract
The substituted benzamide metoclopramide has been reported to block the behavioral effects of dopamine agonists, whereas its congener sulpiride potentiates these effects. We injected metoclopramide 2.0, 4.0, or 8.0 mg/kg PO into rats 2 hr before d-amphetamine 1.5 mg/kg IP and measured locomotion for 3 hr. We injected metoclopramide 8.0 mg/kg PO into rats 2 hr before d-amphetamine 1.5, 3.0, or 6.0 mg/kg IP and measured stereotypy for 3 hr. Metoclopramide potentiated the effects of all doses of d-amphetamine on both measures; peak effects occurred in the second or third hr after d-amphetamine injection. Metoclopramide alone tended to reduce behavior. The results suggest that metoclopramide is qualitatively similar to sulpiride in its interaction with d-amphetamine, and that metoclopramide's mechanism of action is not a simple dopaminergic antagonism. Clinicians are advised that metoclopramide, which is presently extensively for gastrointestinal and other disorders, may interact adversely with drugs that affect dopaminergic function.
- Published
- 1987
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