Ropinirole, sold under the brand name Requip among others, is a

medication Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to medical diagnosis, diagnose, cure, treat, or preventive medicine, prevent disease. Drug therapy (pharmaco ...

used to treat

Parkinson's disease Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become ...

(PD) and restless legs syndrome (RLS). It is taken

by mouth Oral administration is a route of administration whereby a substance is taken through the Human mouth, mouth, swallowed, and then processed via the digestive system. This is a common route of administration for many medications. Oral administ ...

. Common side effects include sleepiness, vomiting, and dizziness. Serious side effects may include pathological gambling, hypersexuality, low blood pressure with standing and

hallucinations A hallucination is a perception in the absence of an external stimulus that has the compelling sense of reality. They are distinguishable from several related phenomena, such as dreaming ( REM sleep), which does not involve wakefulness; pse ...

. Use in

pregnancy Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Conception (biology), Conception usually occurs ...

and

breastfeeding Breastfeeding, also known as nursing, is the process where breast milk is fed to a child. Infants may suck the milk directly from the breast, or milk may be extracted with a Breast pump, pump and then fed to the infant. The World Health Orga ...

is of unclear safety. It is a dopamine agonist and works by triggering dopamine D₂ receptors. It was approved for medical use in the United States in 1997. It is available as a generic medication. In 2022, it was the 163rd most commonly prescribed medication in the United States, with more than 3million prescriptions.

Medical uses

Ropinirole is prescribed for mainly

, restless legs syndrome, and

extrapyramidal symptoms Extrapyramidal symptoms (EPS) are signs and symptoms, symptoms that are wikt:archetypical, archetypically associated with the extrapyramidal system of the brain's cerebral cortex. When such symptoms are caused by medications or other drugs, they ...

. It can also reduce the side effects caused by selective serotonin reuptake inhibitors, including Parkinsonism syndrome as well as

sexual dysfunction Sexual dysfunction is difficulty experienced by an individual or partners during any stage of normal sexual activity, including physical pleasure, desire, preference, arousal, or orgasm. The World Health Organization defines sexual dysfunction ...

and

erectile dysfunction Erectile dysfunction (ED), also referred to as impotence, is a form of sexual dysfunction in males characterized by the persistent or recurring inability to achieve or maintain a Human penis, penile erection with sufficient rigidity and durat ...

caused by either

SSRI Selective serotonin reuptake inhibitors (SSRIs) are a class of drugs that are typically used as antidepressants in the treatment of major depressive disorder, anxiety disorders, and other psychological conditions. SSRIs primarily work by ...

s or antipsychotics. A 2008

meta-analysis Meta-analysis is a method of synthesis of quantitative data from multiple independent studies addressing a common research question. An important part of this method involves computing a combined effect size across all of the studies. As such, th ...

found that ropinirole was less effective than pramipexole in the treatment of restless legs syndrome.

Side effects

Ropinirole can cause nausea, dizziness, hallucinations, orthostatic hypotension, and sudden sleep attacks during the daytime. Unusual side effects specific to D₃ agonists such as ropinirole and pramipexole can include hypersexuality,

punding Punding is compulsive performance of repetitive, mechanical tasks, such as assembling and disassembling, collecting, or sorting objects. It can also apply to digital objects, such as computer files and data. The term was originally coined to desc ...

and compulsive gambling, even in patients without a history of these behaviours. Ropinirole is also known to cause an effect known as "augmentation" when used to treat restless legs syndrome, where over time treatment with dopamine agonists will cause restless legs syndrome symptoms to become more severe. This usually leads to constant dosage increases in an attempt to offset the symptom progression. Symptoms will return to the level of severity they were experienced at before treatment was initiated if the drug is stopped; however, both ropinirole and pramipexole are known to cause painful withdrawal effects when treatment is stopped and the process of taking a patient who has been using the medication long-term off of these drugs is often very difficult and generally should be supervised by a medical professional.

Pharmacology

Ropinirole acts as a D₂, D₃, and D₄

dopamine Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. It is an amine synthesized ...

receptor Receptor may refer to: * Sensory receptor, in physiology, any neurite structure that, on receiving environmental stimuli, produces an informative nerve impulse *Receptor (biochemistry), in biochemistry, a protein molecule that receives and respond ...

agonist An agonist is a chemical that activates a Receptor (biochemistry), receptor to produce a biological response. Receptors are Cell (biology), cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an R ...

with highest

affinity Affinity may refer to: Commerce, finance and law * Affinity (law), kinship by marriage * Affinity analysis, a market research and business management technique * Affinity Credit Union, a Saskatchewan-based credit union * Affinity Equity Pa ...

for D₃, which are mostly found in the limbic areas. It is weakly active at the 5-HT₂, and α₂ receptors and is said to have virtually no affinity for the 5-HT₁, GABA, mAChRs, α₁-, and β-adrenoreceptors. It is a potent agonist of the 5-HT_2B receptor, but shows biased agonism at this receptor and does not appear to pose a risk of cardiac valvulopathy. Ropinirole is metabolized primarily by

cytochrome P450 Cytochromes P450 (P450s or CYPs) are a Protein superfamily, superfamily of enzymes containing heme as a cofactor (biochemistry), cofactor that mostly, but not exclusively, function as monooxygenases. However, they are not omnipresent; for examp ...

CYP1A2 to form two

metabolites In biochemistry, a metabolite is an intermediate or end product of metabolism. The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, c ...

; SK&F-104557 and SK&F-89124, both of which are renally excreted, and at doses higher than clinical, is also metabolized by

CYP3A4 Cytochrome P450 3A4 (abbreviated CYP3A4) () is an important enzyme in the body, mainly found in the liver and in the intestine, which in humans is encoded by ''CYP3A4'' gene. It organic redox reaction, oxidizes small foreign organic molecules ( ...

. At doses greater than 24 mg, CYP2D6 may be inhibited, although this has been tested only

in vitro ''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in ...

Society and culture

It is manufactured by

GlaxoSmithKline GSK plc (an acronym from its former name GlaxoSmithKline plc) is a British Multinational corporation, multinational Pharmaceutics, pharmaceutical and biotechnology company with headquarters in London. It was established in 2000 by a Mergers an ...

(GSK), Mylan Pharmaceuticals, Cipla, Dr. Reddy's Laboratories and Sun Pharmaceutical. The discovery of the drug's utility in restless legs syndrome has been used as an example of successful drug repurposing.

Lawsuit

In November 2012,

was ordered by a

Rennes Rennes (; ; Gallo language, Gallo: ''Resnn''; ) is a city in the east of Brittany in Northwestern France at the confluence of the rivers Ille and Vilaine. Rennes is the prefecture of the Brittany (administrative region), Brittany Regions of F ...

appeals court to pay Frenchman Didier Jambart 197,000 euros ($255,824); Jambart had taken ropinirole from 2003 to 2010 and exhibited risky hypersexual behavior and gambled excessively until stopping the medication. This behavior displayed is character of Dopamine Dysregulation Syndrome.

References

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