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Pronunciation | /ˌpræmɪˈpɛksoʊl/ |
Trade names | Mirapex, Mirapexin, Sifrol, others |
AHFS/Drugs.com | Monograph |
MedlinePlus | a697029 |
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Routes of administration | By mouth |
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Pharmacokinetic data | |
Bioavailability | >90% |
Protein binding | 15% |
Elimination half-life | 8–12 hours |
Excretion | Urine (90%), feces (2%) |
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ECHA InfoCard | 100.124.761 |
Chemical and physical data | |
Formula | C10H17N3S |
Molar mass | 211.33 g·mol−1 |
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Pramipexole, sold under the brand Mirapex among others, is a medication used to treat Parkinson's disease (PD) and restless legs syndrome (RLS). [8] In Parkinson's disease it may be used alone or together with levodopa. [8] It is taken by mouth. [8] Pramipexole is a dopamine agonist of the non-ergoline class. [8]
Pramipexole was approved for medical use in the United States in 1997. [8] It is available as a generic medication. [9] In 2022, it was the 193rd most commonly prescribed medication in the United States, with more than 2 million prescriptions. [10] [11]
Pramipexole is used in the treatment of Parkinson's disease (PD) and restless legs syndrome (RLS). [8] Use in pregnancy and breastfeeding is of unclear safety. [1]
A 2008 meta-analysis found that Pramipexole was more effective than Ropinirole in the treatment of RLS. [12]
It is occasionally prescribed off-label for depression. Its effectiveness as an antidepressant may be a product of its strong partial agonistic activity on and preferential occupation of dopamine D3 receptors at low doses (see table below); as well, the drug has been shown to desensitize the inhibitory D2 autoreceptors but not the postsynaptic D2 receptors, leading to an increase in dopamine and serotonin levels in the prefrontal cortex. [13] Chronic administration of Pramipexole may also result in desensitization of D3 autoreceptors, leading to reduced dopamine transporter function. [14] Trials have shown mixed results for depression. [15]
Pramipexole has also been used as a treatment for REM sleep behaviour disorder, but it is not licensed for use in this disorder. Observational studies suggest it may reduce the frequency and intensity of REM sleep behavior disorder symptoms, but randomized controlled trials have not been performed, so the evidence for its role in this disorder is weak. [16]
Common side effects of Pramipexole may include: [17] [4] [5]
The activity profile of Pramipexole at various sites has been characterized as follows:
Site | Affinity (Ki, nM) | Efficacy (Emax, %) | Action |
---|---|---|---|
D2S | 3.3 | 130 | Super agonist |
D2L | 3.9 | 99 | Full agonist |
D3 | 0.5 | 98 | Full agonist |
D4 | 3.9 | 91 | Full agonist |
Notes: Pramipexole also possesses lower affinity (500–10,000 nM) for the 5-HT1A, 5-HT1B, 5-HT1D, and α2-adrenergic receptors. [28] [34] It has negligible affinity (>10,000 nM) for the D1, D5, 5-HT2, α1-adrenergic, β-adrenergic, H1, and mACh receptors. [28] [34] All sites were assayed using human materials. [28] [29] Pramipexole is a super agonist at the presynaptic D2S receptor, S referring to a shorter amino acid sequence which desensitize overtime unlike postsynaptic D2L receptors. |
While Pramipexole is used clinically (see below), its D3-preferring receptor binding profile has made it a popular tool compound for preclinical research. For example, Pramipexole has been used (in combination with D2- and or D3-preferring antagonists) to discover the role of D3 receptor function in rodent models and tasks for neuropsychiatric disorders. [35] Of note, it appears that Pramipexole , in addition to having effects on dopamine D3 receptors, may also affect mitochondrial function via a mechanism that remains less understood. A pharmacological approach to separate dopaminergic from non-dopaminergic (e.g. mitochondrial) effects of Pramipexole has been to study the effects of the R-stereoisomer of Pramipexole (which has much lower affinity to the dopamine receptors when compared to the S-isomer) side by side with the effects of the S-isomer. [36]
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 neurons, which are nerve cells 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 properly 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 for the D2, D3, and D4 dopamine receptors, Pramipexole may directly stimulate the underfunctioning dopamine receptors in the striatum, thereby restoring the dopamine signals needed for proper functioning of the basal ganglia.
Pramipexole can increase growth hormone indirectly through its inhibition of somatostatin. [37]
Immediate-Release Pramipexole displays a Tmax of approximately 2 hours and 3 hours if taken with a high-fat meal. Extended-Release Pramipexole displays a Tmax of ~6 hours and ~8 hours if taken with food. The AUC of Pramipexole remains unaltered regardless of food presence. Steady-State is achieved within 3 days and 5 days for the IR and ER formulation respectively. Pramipexole is eliminated via the renal organic cation transporter as an unchanged drug showing no signs of any hepatic-mediated metabolism. Pramipexole has been shown to inhibit CYP2D6 with a Ki of 30μM which is significantly higher than the maximum approved dosage of 4.5mg/day thus any enzyme-mediated drug interactions wouldn't be clinically relevant. [38] [39]
Brand names include Mirapex, Mirapex ER, Mirapexin, Sifrol, Glepark, and Oprymea.[ citation needed ]
Pramipexole has been evaluated for the treatment of sexual dysfunction experienced by some users of selective serotonin reuptake inhibitor (SSRI) antidepressants. [40] Pramipexole has shown effects on pilot studies in a placebo-controlled proof of concept study in bipolar disorder. [41] [42] [43] It is also being investigated for the treatment of clinical depression and fibromyalgia. [44] [45] [46]
Derivatives of Pramipexole include CJ-998, CJ-1037, CJ-1638, CJ-1639, [47] D-264, D-440, [48] and D-512. [48]
Restless legs syndrome (RLS), (also known as Willis–Ekbom disease(WED), is a neurological disorder, usually chronic, that causes an overwhelming urge to move one's legs. There is often an unpleasant feeling in the legs that improves temporarily by moving them. This feeling is often described as aching, tingling, or crawling in nature. Occasionally, arms may also be affected. The feelings generally happen when at rest and therefore can make it hard to sleep. Sleep disruption may leave people with RLS sleepy during the day, with low energy, and irritable or depressed. Additionally, many have limb twitching during sleep, a condition known as periodic limb movement disorder. RLS is not the same as habitual foot-tapping or leg-rocking.
Aripiprazole, sold under the brand names Abilify and Aristada, among others, is an atypical antipsychotic. It is primarily used in the treatment of schizophrenia and bipolar disorder; other uses include as an add-on treatment in major depressive disorder and obsessive–compulsive disorder (OCD), tic disorders, and irritability associated with autism. Aripiprazole is taken by mouth or via injection into a muscle. A Cochrane review found low-quality evidence of effectiveness in treating schizophrenia.
Dopamine receptors are a class of G protein-coupled receptors that are prominent in the vertebrate central nervous system (CNS). Dopamine receptors activate different effectors through not only G-protein coupling, but also signaling through different protein interactions. The neurotransmitter dopamine is the primary endogenous ligand for dopamine receptors.
A dopamine antagonist, also known as an anti-dopaminergic and a dopamine receptor antagonist (DRA), is a type of drug which blocks dopamine receptors by receptor antagonism. Most antipsychotics are dopamine antagonists, and as such they have found use in treating schizophrenia, bipolar disorder, and stimulant psychosis. Several other dopamine antagonists are antiemetics used in the treatment of nausea and vomiting.
Cabergoline, sold under the brand name Dostinex among others, is a dopaminergic medication used in the treatment of high prolactin levels, prolactinomas, Parkinson's disease, and for other indications. It is taken by mouth.
Dopaminergic means "related to dopamine", a common neurotransmitter. Dopaminergic substances or actions increase dopamine-related activity in the brain.
Ropinirole, sold under the brand name Requip among others, is a medication used to treat Parkinson's disease (PD) and restless legs syndrome (RLS). It is taken by mouth.
Amisulpride, sold under the brand names Solian and Barhemsys, is a medication used in the treatment of schizophrenia, acute psychotic episodes, depression, and nausea and vomiting. It is specifically used at lower doses intravenously to prevent and treat postoperative nausea and vomiting; at low doses by mouth to treat depression; and at higher doses by mouth to treat psychosis.
A dopamine agonist is a compound that activates dopamine receptors. There are two families of dopamine receptors, D1-like and D2-like. They are all G protein-coupled receptors. D1- and D5-receptors belong to the D1-like family and the D2-like family includes D2, D3 and D4 receptors. Dopamine agonists are primarily used in the treatment of the motor symptoms of Parkinson's disease, and to a lesser extent, in hyperprolactinemia and restless legs syndrome. They are also used off-label in the treatment of clinical depression. Impulse control disorders are associated with the use of dopamine agonists for whatever condition.
Rotigotine, sold under the brand name Neupro among others, is a dopamine agonist of the non-ergoline class of medications indicated for the treatment of Parkinson's disease and restless legs syndrome. It is formulated as a once-daily transdermal patch which provides a slow and constant supply of the drug over the course of 24 hours.
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.
Dihydroergocryptine (DHEC), sold under the brand names Almirid and Cripar among others, is a dopamine agonist of the ergoline group that is used as an antiparkinson agent in the treatment of Parkinson's disease. It is taken by mouth.
Dopamine receptor D3 is a protein that in humans is encoded by the DRD3 gene.
Istradefylline, sold under the brand name Nourianz, is a medication used as an add-on treatment to levodopa/carbidopa in adults with Parkinson's disease (PD) experiencing "off" episodes. Istradefylline reduces "off" periods resulting from long-term treatment with the antiparkinson drug levodopa. An "off" episode is a time when a patient's medications are not working well, causing an increase in PD symptoms, such as tremor and difficulty walking.
Dopamine dysregulation syndrome (DDS) is a dysfunction of the reward system observed in some individuals taking dopaminergic medications for an extended length of time. It is characterized by severely disinhibited patterns of behavior, leading to problems such as addiction to the offending medication, gambling addiction, or compulsive sexual behavior, along with a general orientation towards immediate gratification. It typically occurs in people with Parkinson's disease or restless legs syndrome (RLS) who have taken dopamine agonist medications for an extended period of time.
Pardoprunox (INN) is an antiparkinsonian drug developed by Solvay for the treatment of Parkinson's disease that reached phase III clinical trials before being discontinued. It was also being investigated for the treatment of depression and anxiety but these indications appear to have been abandoned as well.
Roxindole (EMD-49,980) is a dopaminergic and serotonergic drug which was originally developed by Merck KGaA for the treatment of schizophrenia. In clinical trials its antipsychotic efficacy was only modest but it was unexpectedly found to produce potent and rapid antidepressant and anxiolytic effects. As a result, roxindole was further researched for the treatment of depression instead. It has also been investigated as a therapy for Parkinson's disease and prolactinoma.
Sumanirole (PNU-95,666) is a highly selective D2 receptor full agonist, the first of its kind to be discovered. It was developed for the treatment of Parkinson's disease and restless leg syndrome. While it has never been approved for medical use it is a highly valuable tool compound for basic research to identify neurobiological mechanisms that are based on a dopamine D2-linked (vs. D1-, D3-, D4-, and D5-linked) mechanism of action.
Cariprazine, sold under the brand name Vraylar among others, is an atypical antipsychotic developed by Gedeon Richter, which is used in the treatment of schizophrenia, bipolar mania, bipolar depression, and major depressive disorder. It acts primarily as a D3 and D2 receptor partial agonist, with a preference for the D3 receptor. Cariprazine is also a partial agonist at the serotonin 5-HT1A receptor and acts as an antagonist at 5-HT2B and 5-HT2A receptors, with high selectivity for the D3 receptor. It is taken by mouth. The most prevalent side effects include nausea, mild sedation, fatigue, and dizziness. At higher dosages, there is an increased risk for restlessness, insomnia, and tremors.
Mesdopetam (INNTooltip International Nonproprietary Name; developmental code names IRL-790, IPN60170) is a dopamine D2 and D3 receptor antagonist with preference for the D3 receptor which is under development for the treatment of Parkinson's disease, drug-induced dyskinesia, and psychotic disorders. It has been described by its developers as having "psychomotor stabilizing" properties.
... features of ICSDs [impulsive-compulsive spectrum disorders] during D2/D3R treatment are consistent with the pharmacological profile of the drugs, the known role of D2/D3R in these behaviors, and the neuroanatomical substrates of D2/D3R-expressing brain systems of ICSDs as shown by modern human imaging studies. While we pose that D2/D3R agonist treatment is sufficient to mediate ICSDs, there likely are many factors that overlay this profile, e.g., genetic vulnerabilities, brain disease state, and maladaptations to the chronic therapy.
… the specific goals of the current review were to … separately identify the RLS-specific side effect, which is augmentation.
Augmentation of symptoms of restless legs syndrome (e.g., earlier onset of symptoms in the evening or afternoon, increase in symptoms, spread of symptoms to involve other extremities) reported; incidence increased with increasing duration of pramipexole treatment.
… augmentation of the RLS symptoms is a major limitation of oral dopaminergic therapy.