Behavioral changes as a result of dotarizine or flunarizine influence on dopaminergic neurotransmission in the striatum.

In experiments on rats, we studied the changes in stereotypy induced by apomorphine (2.5 mg/kg i.p.) or amphetamine (2 mg/kg i.p.) and in haloperidol (1 mg/kg i.p.) catalepsy in rats treated with dotarizine (25 mg/kg orally), flunarizine (25 mg/kg) or vehicle for 10 days. Dotarizine did not induce any significant changes in the intensity and duration of apomorphine- or amphetamine-induced stereotypy nor in haloperidol-induced catalepsy. The flunarizine-induced changes in the behavioral effects of apomorphine, amphetamine and haloperidol suggest the decrease of striatal dopaminergic neurotransmission, whereby the risk of occurrence of extrapyramidal side effects of the drug when used in clinical practice. Dotarizine is not associated with such a risk.