dopamine receptor agonist is a compound that activates dopamine receptors. Dopamine receptor agonists activate signaling pathways through trimeric G-proteins and β-arrestins, ultimately leading to changes in gene transcription.
Today, for several dopamine receptor subtypes (D1, D2, D3) agonists are known, that differentially address these signalling pathways. They are called
biased agonists.    
drugs act as dopamine agonists and can treat hypodopaminergic (low dopamine) conditions; they are typically used for treating Parkinson's disease (PD), Attention deficit hyperactivity disorder (in the form of stimulants) and certain pituitary tumors ( prolactinoma), and may be useful for restless legs syndrome (RLS). Both ropinirole and pramipexole are FDA-approved for the treatment of RLS. There is also an ongoing clinical trial to test the effectiveness of the dopamine agonist ropinirole in reversing the symptoms of SSRI- induced sexual dysfunction. Additionally, a systematic review and meta-analysis concluded that prophylactic treatment with  cabergoline reduces the incidence, but not the severity, of ovarian hyperstimulation syndrome (OHSS), without compromising pregnancy outcomes, in females undergoing stimulated cycles of in vitro fertilization ( IVF).
Some of the common side effects of dopamine agonists include:
Pericardial effusion Fibrous thickening of lining that covers some of the internal organs including the heart or the lungs (fibrotic reaction)
Hallucinations Causing or worsening
Orthostatic hypotension Increased
Nausea and possible vomiting
Insomnia Unusual tiredness or weakness
Narcolepsy manifestations (Sleep attacks) 
Raynaud's phenomenon (common side effect of ergot derivatives)
Syncope Twitching, twisting, or other unusual body movements
Pathological addiction (gambling, shopping, internet pornography, hyper-sexuality) – specifically
D-preferring agonists 3 After long-term use of dopamine agonists, a withdrawal syndrome may occur, during dose reduction or discontinuation, with the following possible side effects: anxiety, panic attacks, dysphoria, depression, agitation, irritability, suicidal ideation, fatigue, orthostatic hypotension, nausea, vomiting, diaphoresis, generalized pain, and drug cravings. For some individuals, these withdrawal symptoms are short-lived and make a full recovery, for others a protracted withdrawal syndrome may occur with withdrawal symptoms persisting for months or years. 
dopamine agonists include:
Agonists of full/unknown efficacy
Some, such as
fenoldopam, are selective for dopamine receptor D1.
There are two
classes of drugs that act as indirect agonists of dopamine receptors: dopamine reuptake inhibitors and dopamine releasing agents.
The most commonly prescribed indirect agonists of dopamine receptors include:
Other examples include:
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^ Clinical trial number
at NCT00334048 ClinicalTrials.gov - "Treating Sexual Dysfunction From SSRI Medication: a Study Comparing Requip CR to Placebo"
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FDA Announces Voluntary Withdrawal of Pergolide Products
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