Ropinirole

drugbox
IUPAC_name = 4-(2-dipropylaminoethyl)-1,3-dihydroindol-2-one

---

width = 160


CAS_number = 91374-21-9
ATC_prefix = N04
ATC_suffix = BC04
ATC_supplemental =
PubChem = 5095
DrugBank = APRD00302
C=16 | H=24 | N=2 | O=1
molecular_weight = 260.375 g/mol
bioavailability = 50% cite journal| author=Tompson, Debra J. "et al."| title=Steady-State Pharmacokinetic Properties of a 24-Hour Prolonged-Release Formulation of Ropinirole: Results of Two Randomized Studies in Patients with Parkinson’s Disease| journal=Clinical Pharmacokinetics| year=2007| volume=29| doi=10.1016/j.clinthera.2007.12.010| pages=2654 ]
protein_bound =
metabolism = hepatic (CYP1A2)
elimination_half-life = 5-6 hours
pregnancy_category = C
legal_status = Rx
routes_of_administration = Oral

Ropinirole (marketed under the brand names Requip and Ropark, in extended release form as Requip XL) is a non-ergoline dopamine agonist. It is manufactured by GlaxoSmithKline and Sun Pharmaceuticals. It is used in the treatment of Parkinson's disease. Ropinirole and is also one of two medications in the United States with an FDA-approved indication for the treatment of restless legs syndrome (RLS), the other being pramipexole. The discovery of the drug's utility in RLS has been used as a successful example of drug repurposing.Citation
last =Lipp | first =Elizabeth | date =2008-08-01 | year =2008
title =Novel Approaches to Lead Optimization
periodical =Genetic Engineering & Biotechnology News
series =Drug Discovery
publisher =Mary Ann Liebert | volume =28 | issue =14 | pages =20
url =http://www.genengnews.com/articles/chitem.aspx?aid=2550
issn =1935-472X | accessdate =2008-09-28 "Note: The opinion that ropinirole's use in RLS was a successful example of drug repurposes was reported as being that of Josef Scheiber, a post-doctoral fellow at the Novartis Institutes for BioMedical Research."]

Ropinirole's patent expired in May 2008, and the drug is now available in generic form. [ [http://www.tevausa.com/default.aspx?pageid=75 New pharmaceutical products: Ceftriaxon-Rocephin, Granisetron-Kytril, Ipratropium-Albuterol ] ]

Dosing

Requip (it is marketed as Adartrel in Europe for the restless legs syndrome indication and as Requip for the anti-Parkinson indication) is available in various preparations, ranging from the .25 mg tablet to the 5 mg tablet. The primary reason for such is dose titration. This implies that the person taking Requip has to closely interact and communicate with the primary care physician with regard to how much should actually be taken by the patient.

For restless legs Syndrome (RLS), the maximum recommended dose is 4 mg per day, taken 1 to 3 hours before bedtime. A 52-week open label study had a mean dosage of 1.90mg, once daily 1-3 hours before bedtime. cite journal| author=Garcia-Borreguero, Diego "et al."| title=A 52-week open-label study of the long-term safety of ropinirole in patients with restless legs syndrome| journal=Sleep Medicine| year=2007| pages=742–752| doi=10.1016/j.sleep.2006.09.009| volume=8 ]

For Parkinson's disease (PD), the maximum recommended dose is 24 mg per day, taken in three separate doses spread throughout the day.

Mechanism

Ropinirole acts as an agonist at the D2 and D3 dopamine receptor subtypes, binding with higher affinity to D3 than to D2 or D4 and It has no affinity for D1 receptors. It has medium in vitro affinity to opioid receptors. Ropinirole is weakly active at the 5-HT2, and α₂ receptors and is said to have virtually no affinity to 5-HT1, benzodiazepine, GABA, muscarinic, α₁, and β-adrenoreceptors.cite journal | author=Eden, R. J. "et al."| title=Preclinical Pharmacology of Ropinirole (SK&F 101468-A) a Novel Dopamine D 2 Agonist| year=1991| journal=Pharmacology Biochemistry & Behavior| volume=38| pages=147–154| doi=10.1016/0091-3057(91)90603-Y ]

Ropinirole is metabolized primarily by cytochrome P450 CYP1A2, and at doses higher than clinical, is also metabolized by CYP3A4. At doses greater than 24mg, CYP2D6 may be inhibited, although this has only been tested in vitro.

References

External links

* [http://www.requip.com Requip for RLS]
* [http://www.requip.com/pd Requip for PD]
* [http://www.rxlist.com/cgi/generic2/ropinirole_cp.htm Requip - Clinical Pharmacology]