Pramipexole
3987386
224709578
2008-07-10T01:52:06Z
Uthbrian
562409
/* Mechanism of action */ +diagram
{{drugbox
| IUPAC_name = (6''S'')-N<sup>6</sup>-propyl-4,5,6,7-tetrahydro-1,3-benzothiazole-2,6-diamine
| image = Pramipexole.svg
| CAS_number = 104632-26-0
| ATC_prefix = N04
| ATC_suffix = BC05
| ATC_supplemental =
| PubChem = 59868
| DrugBank = APRD00156
| C = 10 | H = 17 | N = 3 | S = 1
| molecular_weight = 211.324 g/mol
| bioavailability = >90%
| protein_bound = 15%
| metabolism = Minimal
| elimination_half-life = 8 hours
| excretion = [[Kidney|Renal]] (90%) and fecal (2%)
| licence_EU = Sifrol
| licence_US = Pramipexole
| pregnancy_AU = B3
| pregnancy_US = C
| legal_status = Rx-only
| routes_of_administration = Oral
}}
'''Pramipexole''' ([[International Nonproprietary Name|INN]], trade names '''Mirapex''' and '''Sifrol''') is a [[medication]] indicated for treating [[Parkinson's disease]] and [[restless legs syndrome]] (RLS). It is also sometimes used [[Off-label use|off-label]] as a treatment for [[cluster headache]] or to counteract the problems with low [[libido]] experienced by some users of [[SSRI]] antidepressant drugs. Pramipexole has shown robust effects on pilot studies in a placebo-controlled proof of concept study in [[bipolar disorder]]<ref>Biol Psychiatry. 2004 Jul 1;56(1):54-60. Pramipexole for bipolar II depression: a placebo-controlled proof of concept study.Zarate CA Jr, Payne JL, Singh J, Quiroz JA, Luckenbaugh DA, Denicoff KD, Charney DS, Manji HK.PMID: 15219473</ref>. Pramipexole is classified as a non-[[ergoline]] [[dopamine agonist]].
==Mechanism of action==
[[Image:basal-ganglia-classic.png|thumb|[[Basal ganglia]] connectivity diagram showing [[glutamatergic]] pathways as red, [[dopaminergic]] as magenta and [[GABA]] pathways as blue.]]
The [[basal ganglia]] is a region of the [[human brain]] involved in the regulation of body movement; hence, when components of the basal ganglia are damaged, disorders of body movement may occur.
Parkinson's disease is a [[neurodegenerative disease]] affecting the [[substantia nigra]], a component of the [[basal ganglia]]. The substantia nigra has a high quantity of dopaminergic [[neuron]]s, which are neurons that release the [[neurotransmitter]] known as [[dopamine]]. When dopamine is released, it may activate dopamine receptors in the [[striatum]], which is another component of the basal ganglia. When neurons of the substantia nigra deteriorate in Parkinson's disease, the striatum no longer receives dopamine signals. As a result, the basal ganglia can no longer regulate body movement effectively and motor function becomes impaired.
By acting as an [[agonist]] to the [[dopamine receptor]]s, pramipexole may directly stimulate dopamine receptors in the [[striatum]], thereby restoring the dopamine signals needed for proper functioning of the basal ganglia. Any depressant effects are most likely the result of pramipexole binding to the [[Dopamine receptor D2|D<sub>2</sub>]] receptor subtype, which exhibits inhibitory behavior.
Pramipexole binds to dopamine receptors, with particularly high affinity for the [[Dopamine receptor D3|D<sub>3</sub>]] receptor subtype.<ref>{{cite journal | author = Mierau J, Schneider F, Ensinger H, Chio C, Lajiness M, Huff R | title = Pramipexole binding and activation of cloned and expressed dopamine D2, D3 and D4 receptors. | journal = Eur J Pharmacol | volume = 290 | issue = 1 | pages = 29–36 | year = 1995 | pmid = 7664822 | doi = 10.1016/0922-4106(95)90013-6}}</ref>
==Adverse effects==
Some of the more common side effects of pramipexole include:<ref>
{{cite web |url= http://www.nlm.nih.gov/medlineplus/druginfo/uspdi/203739.html |title= MedlinePlus Drug Information: Pramipexole (Systemic) |accessdate= 2006-09-27 |publisher= [[United States National Library of Medicine]]}}</ref>
* Dizziness, lightheadedness, or fainting, especially when standing up ([[orthostatic hypotension]])
* Drowsiness
* [[Hallucination]]s (seeing, hearing, or feeling things that are not there)
* Weight gain
* Weight loss
* [[Nausea]]
* Trouble in [[sleep]]ing
* Twitching, twisting, or other unusual body movements
* Unusual tiredness or weakness
Several unusual adverse effects of this medication may include [[compulsive gambling]], [[hypersexuality]], and [[overeating]]. These side effects may be linked to the D<sub>3</sub> receptor agonist activity of pramipexole. D<sub>3</sub> receptors are located in brain regions involved in mood, behavior, and rewards.<ref>{{cite web |url= http://www.mayoclinic.com/health/parkinsons-disease/BN00043 |title= Parkinson's drug can cause compulsive gambling |accessdate= 2006-09-27 |author= Mayo Clinic Staff|authorlink= |coauthors= M. Leann Dodd |date= July 15, 2005 |publisher= [[Mayo Clinic]]}}</ref>
==References==
===Notes===
{{Reflist}}
===Sources===
* [http://www.rxlist.com/cgi/generic2/prampex_cp.htm RxList.com] - Pramipexole (Mirapex)
==External links==
* [http://www.mirapex.com/ Mirapex.com] - Manufacturer's website
{{Dopamine agonists}}
[[Category:Dopamine agonists]]
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