Bromocriptine-induced behavioral hypersensitivity: implications for the therapy of parkinsonism.
Bromocriptine (CB-154) is a direct-acting dopamine agonist of proven clinical efficacy in parkinsonism. The capacity of bromocriptine to induce receptor site hypersensitivity was investigated utilizing a behavioral model in guinea pigs. Following 4 weeks of bromocriptine treatment, animals demonstrated a subsequent long-lasting hypersensitivity to amphetamine and apomorphine. The data suggest that chronic use of bromocriptine can induce receptor site hypersensitivity. These results may be an indication that, because of a similar propensity to side effects during chronic therapy, direct-acting dopamine agonists will offer no long-term advantage over current antiparkinsonian drugs. The observed phenomena suggest that chronic dopaminergic agonism may not be an ideal therapy for parkinsonism.
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D001519:Behavior / Q000187:drug effects*; D001971:Bromocriptine / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D003913:Dextroamphetamine / Q000494:pharmacology; D006168:Guinea Pigs; D006801:Humans; D008297:Male; D010300:Parkinson Disease / Q000188:drug therapy*; D013239:Stereotyped Behavior / Q000187:drug effects*
D001971:Bromocriptine; D001058:Apomorphine; D003913:Dextroamphetamine