Piribedil

Piribedil (trade names Pronoran, Trivastal Retard, Trastal, Trivastan, Clarium and others) is an antiparkinsonian agent and piperazine derivative which acts as a D2 and D3 receptor agonist. It also has α2-adrenergic antagonist properties.
Medical uses.
Other uses.
The drug has been shown to enhance working memory capacities in normal aging adults.
In age-related memory impairment, it has a positive effect on psychophysiological state of elderly people, improving memory and attention and increasing the velocity of psychomotor reactions and lability of nervous processes.
It enhances cognitive skill learning in healthy older adults.
It showed a positive effect in restless legs syndrome.
Dosage.
Parkinson's disease.
Administration of piribedil should be initiated with one sustained-release tablet (50 mg) daily during the first week. Dosage should then be gradually increased every week until achieving the optimal therapeutic dose:
Other indications.
One tablet daily at the end of the main meal. In severe cases: two tablets daily in two doses.
Side effects.
As with other dopamine agonists (like pramipexole and ropinirole), compulsive behavior like pathological gambling, overeating, excessive shopping, increased libido, sexual and/or other intense urges, may develop.
Another rare side effect of piribedil is excessive daytime sleepiness and unintended sleep episodes.
Overdose.
At very high doses, piribedil has an emetic action on the chemoreceptor trigger zone (CTZ). Tablets will thus be rapidly rejected, which explains why no data are currently available concerning the risk of overdosage.
Interactions.
Dopamine antagonists reduce the effect of piribedil.