Piribedil

Piribedil

Clinical data
AHFS/Drugs.com	International Drug Names
Routes of administration	Oral
ATC code	N04BC08 (WHO)
Legal status
Legal status	In general: ℞ (Prescription only)
Pharmacokinetic data
Bioavailability	10% (peak at 1 hour)
Protein binding	70–80%
Metabolism	extensive hepatic
Biological half-life	1.7–6.9 hours
Excretion	Renal (68%) and biliary (25%)
Identifiers
IUPAC name 2-[4-(benzo[1,3]dioxol-5-ylmethyl)piperazin-1-yl]pyrimidine
CAS Number	3605-01-4 Y
PubChem CID	4850
IUPHAR/BPS	49
ChemSpider	4684 N
UNII	DO22K1PRDJ
KEGG	D07305 Y
ChEMBL	CHEMBL1371770 N
ECHA InfoCard	100.020.695
Chemical and physical data
Formula	C16H18N4O2
Molar mass	298.340 g/mol
3D model (Jmol)	Interactive image
SMILES C1CN(CCN1CC2=CC3=C(C=C2)OCO3)C4=NC=CC=N4
InChI InChI=1S/C16H18N4O2/c1-4-17-16(18-5-1)20-8-6-19(7-9-20)11-13-2-3-14-15(10-13)22-12-21-14/h1-5,10H,6-9,11-12H2 N Key:OQDPVLVUJFGPGQ-UHFFFAOYSA-N N
NY (what is this?)

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.

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.

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:

One tablet daily at the end of the main meal. In severe cases: two tablets daily in two doses.

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.

Dopamine antagonists reduce the effect of piribedil.

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.