Preliminary Study of B-HT 920, a Novel Dopamine Agonist, for the Treatment of Parkinson’s Disease

The therapeutic efficacy of a new partial dopamine receptor agonist, B-HT 920 (talipexole hydrochloride) is discussed. B-HT 920 is primarily a presynaptic dopamine receptor agonist that inhibits the release of dopamine from the synaptic terminals. However, with degenerated dopaminergic terminals, it acts as a postsynaptic dopamine receptor agonist. This drug is therefore expected to possess antiparkinsonian properties with fewer emetic side effects. This hypothesis was examined in 56 patients with Parkinson’s disease. The clinical efficacy of B-HT 920 was comparable with that of the conventional agonists, whereas the incidence of epigastric discomfort was 10.7%, of anorexia was 7.1%, and of nausea was 7.1%, which appeared lower than the incidences reported with the conventional agonists. B-HT 920 seems to be a useful drug for Parkinson’s disease, and our results warrant further studies including double-blind trials.