Evaluation of amphetamine-induced hyperlocomotion and catalepsy following long-acting risperidone administration in rats.
It has been proposed that long-acting risperidone could provide a constant antipsychotic efficacy associated with a reduced liability to induce extra-pyramidal symptoms. To ascertain this hypothesis, antagonism of amphetamine-induced hyperlocomotion and catalepsy were analyzed in rats for a period of 1-6 weeks following long-acting risperidone (20-60 mg/kg) injection. Long-acting risperidone reduced amphetamine-induced hyperlocomotion after 2-5 weeks from drug injection, without producing significant extra-pyramidal symptoms. Following the administration of long-acting risperidone a constant ability to antagonize amphetamine-induced hyperlocomotion was observed during the day, but not when the antipsychotic was chronically administered using a short-acting formulation. The pre-clinical results confirmed that long-acting risperidone may represent an advance in antipsychotic therapy.
Marchese
Giorgio
G
CNR, Institute of Biomedical Technology, Sect Cagliari, Technological Park of Sardinia Sardegna Ricerche, Pula, Cagliari, Italy. giorgio.marchese@cnr.it
Casu
Gianluca
G
Casti
Paola
P
Spada
Gabriele Pinna
GP
Pani
Luca
L
D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D014150:Antipsychotic Agents / Q000008:administration & dosage* / Q000494:pharmacology* / Q000627:therapeutic use; D001522:Behavior, Animal / Q000187:drug effects; D002375:Catalepsy / Q000139:chemically induced* / Q000188:drug therapy / Q000503:physiopathology; D002626:Chemistry, Pharmaceutical; D006948:Hyperkinesis / Q000139:chemically induced* / Q000188:drug therapy / Q000503:physiopathology; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000187:drug effects; D018967:Risperidone / Q000008:administration & dosage* / Q000494:pharmacology* / Q000627:therapeutic use; D013997:Time Factors
D014150:Antipsychotic Agents; D000661:Amphetamine; D018967:Risperidone