Antagonism of apomorphine-induced cage climbing behaviour and methamphetamine stereotypy by fenfluramine in mice.

Pretreatment with fenfluramine (5 and 10 mg/kg, ip) in doses which induced head twitches was found to antagonize apomorphine-induced cage climbing behaviour and methamphetamine stereotypy in mice. Since fenfluramine (5 and 10 mg/kg) did not induce catalepsy it indicates that fenfluramine lacks postsynaptic striatal and mesolimbic dopamine receptor blocking activity and it is possible that the fenfluramine-induced enhancement of central 5-hydroxytryptamine neuronal transmission may be responsible for its antagonistic effect on apomorphine-induced climbing behaviour and methamphetamine stereotypy.