Piribedil
Encyclopedia
Piribedil is an antiparkinsonian agent and piperazine
derivative
which acts as a D2 and D3 receptor agonist
. It also has α2-adrenergic antagonist properties.
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
(CTZ). Tablets will thus be rapidly rejected, which explains why no data are currently available concerning the risk of overdosage.
Piperazine
Piperazine is an organic compound that consists of a six-membered ring containing two opposing nitrogen atoms. Piperazine exists as small alkaline deliquescent crystals with a saline taste....
derivative
Derivative (chemistry)
In chemistry, a derivative is a compound that is derived from a similar compound by some chemical or physical process. In the past it was also used to mean a compound that can be imagined to arise from another compound, if one atom is replaced with another atom or group of atoms, but modern...
which acts as a D2 and D3 receptor agonist
Agonist
An agonist is a chemical that binds to a receptor of a cell and triggers a response by that cell. Agonists often mimic the action of a naturally occurring substance...
. It also has α2-adrenergic antagonist properties.
Indications
- Treatment of Parkinson's diseaseParkinson's diseaseParkinson's disease is a degenerative disorder of the central nervous system...
(PD), either as monotherapy (without L-DOPA (Levodopa)) or in combination with L-DOPA therapy, in the early stages as well as in the advanced stages of the disease. - Treatment of pathological cognitive deficitCognitive deficitCognitive deficit, also known as cognitive impairment is an inclusive term to describe any characteristic that acts as a barrier to cognitive performance...
s in the elderly (impaired attentionAttentionAttention is the cognitive process of paying attention to one aspect of the environment while ignoring others. Attention is one of the most intensely studied topics within psychology and cognitive neuroscience....
, motivationMotivationMotivation is the driving force by which humans achieve their goals. Motivation is said to be intrinsic or extrinsic. The term is generally used for humans but it can also be used to describe the causes for animal behavior as well. This article refers to human motivation...
, memoryMemoryIn psychology, memory is an organism's ability to store, retain, and recall information and experiences. Traditional studies of memory began in the fields of philosophy, including techniques of artificially enhancing memory....
, etc.). - Treatment of dizzinessDizzinessDizziness refers to an impairment in spatial perception and stability. The term is somewhat imprecise. It can be used to mean vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness....
in the elderly. - Treatment of retinaRetinaThe vertebrate retina is a light-sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical...
l ischemic manifestations. - Adjuvant treatment in intermittent claudicationIntermittent claudicationIntermittent claudication is a clinical diagnosis given for muscle pain , classically in the calf muscle, which occurs during exercise, such as walking, and is relieved by a short period of rest.Claudication derives from the Latin verb claudicare, "to limp".-Signs:One of the hallmarks of arterial...
due to peripheral vascular disease (PVD) of the lower limbLower limbThe lower limb is a limb of the body.According to Terminologia Anatomica, it includes the pelvic girdle, buttocks, hip, and thigh, as well as the components distal to the knee.-References:...
s (stage 2). - AnhedoniaAnhedoniaIn psychology and psychiatry, anhedonia is defined as the inability to experience pleasure from activities usually found enjoyable, e.g. hobbies, exercise, social interaction or sexual activity....
and treatment-resistant depression in unipolar and bipolar depressives (off label). - Treatment of gait disorders associated to Parkinson disease (no related cause) and other forms of parkinsonism
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
Parkinson's disease
Administration of piribedil should be initiated with one tablet daily during the first week. Dosage should then be gradually increased every week until achieving the optimal therapeutic dose:- as monotherapy: three to five tablets in three to five doses daily.
- in combination with L-dopa therapy: one to three tablets daily.
Other indications
One tablet daily at the end of the main meal. In severe cases: two tablets daily in two doses.Adverse effects
- Minor gastrointestinal upset (nauseaNauseaNausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...
, vomitingVomitingVomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...
, flatulenceFlatulenceFlatulence is the expulsion through the rectum of a mixture of gases that are byproducts of the digestion process of mammals and other animals. The medical term for the mixture of gases is flatus, informally known as a fart, or simply gas...
, etc.) in predisposed individuals, or when taken between meals: adjust dosage individually, and/or add domperidoneDomperidoneDomperidone is an antidopaminergic drug, developed by Janssen Pharmaceutica, and used orally, rectally or intravenously, generally to suppress nausea and vomiting, or as a prokinetic agent...
(Motilium). - Orthostatic hypotensionOrthostatic hypotensionOrthostatic hypotension, also known as postural hypotension, orthostasis, and colloquially as head rush or dizzy spell, is a form of hypotension in which a person's blood pressure suddenly falls when the person stands up or stretches. The decrease is typically greater than 20/10 mm Hg, and may be...
or drowsiness may occur, particularly in predisposed individuals (underlying condition or causative illness).
Overdose
At very high doses, piribedil has an emetic action on the chemoreceptor trigger zoneChemoreceptor trigger zone
The chemoreceptor trigger zone , is an area of the medulla that receives inputs from blood-borne drugs or hormones, and communicates with the vomiting center, to initiate vomiting. The CTZ is close to the area postrema on the floor of the fourth ventricle and is outside of the blood-brain barrier...
(CTZ). Tablets will thus be rapidly rejected, which explains why no data are currently available concerning the risk of overdosage.
Receptor affinities
- Dopamine receptorDopamine receptorDopamine receptors are a class of metabotropic G protein-coupled receptors that are prominent in the vertebrate central nervous system . The neurotransmitter dopamine is the primary endogenous ligand for dopamine receptors....
agonistAgonistAn agonist is a chemical that binds to a receptor of a cell and triggers a response by that cell. Agonists often mimic the action of a naturally occurring substance...
, selective for subtypes D2 and D3. - Adrenergic receptorAdrenergic receptorThe adrenergic receptors are a class of metabotropic G protein-coupled receptors that are targets of the catecholamines, especially noradrenaline and adrenaline ....
antagonistAntagonistAn antagonist is a character, group of characters, or institution, that represents the opposition against which the protagonist must contend...
, subtypes α2a and α2c: could be the reason why piribedil seems to cause less drowsiness than other dopamine agonists. - Lack of affinity to serotonin receptor 5-HT2B: theoretically no risk of heart valve impairment.
See also
- PramipexolePramipexolePramipexole is a non-ergoline dopamine agonist indicated for treating early-stage Parkinson's disease and restless legs syndrome...
- RopiniroleRopiniroleRopinirole is a non-ergoline dopamine agonist. It is manufactured by GlaxoSmithKline , Cipla and Sun Pharmaceutical. It is used in the treatment of Parkinson's disease...
- RotigotineRotigotineRotigotine is a non-ergoline dopamine agonist indicated for the treatment of Parkinson's disease and restless legs syndrome in Europe and the United States...
- MethylenedioxybenzylpiperazineMethylenedioxybenzylpiperazine1-piperazine is a psychoactive drug of the piperazine chemical class related to benzylpiperazine...