Talipexole is a D2 receptor agonist which was marketed in June 1996 in Japan for the treatment of Parkinson's disease. Clinical trials with talipexole in patients with Parkinson's disease demonstrated statistically significant improvements from baseline for parkinsonian symptoms including akinesia, rigidity, tremor and gait disturbances.

IOLOPRIDE I-123 (also known as I-123 iodobenzamide), a radioactive drug that can be seen by Single-photon emission computed tomography. This drug binds to the some dopamine receptors and can be used in the neonatal period. It shows the biochemical maturation of D2 receptors and also manifests the deleterious effect of perinatal hypoxic-ischemic events on D2 receptors.

Roxindole (EMD-49,980) is a dopaminergic and serotonergic drug which was originally developed for the treatment of schizophrenia. Roxindole has also been investigated as a therapy for the major depressive disorder, Parkinson's disease, and prolactinoma. Roxindole is dopamine autoreceptor-selective agonistic drug with high affinity to D2-like receptors and with much lower affinities to D1-like, % and ol2, muscarinic and 5HT 2 receptors. Additionally, Roxindole exerts 5HT uptake inhibition and 5HT1A agonistic effects. The bioavailability of Roxindole has been estimated at 5% due to a high first-pass metabolization. On the other hand, in 14C distribution studies, Roxindole has crossed the blood-brain barrier readily and the brain concentrations at all intervals have been much higher than corresponding plasma levels. In clinical trials, Roxindole ‘s antipsychotic efficacy was only modest but it was unexpectedly found to produce potent and rapid antidepressant and anxiolytic effects. However, the clinical development of Roxindole was discontinued.

YM-435 is a dopamine D1 agonist. The renal and cardiovascular effects of YM-435 may be suitable for the treatment of patients with renal insufficiency, heart failure and hypertension. It has been in phase II clinical trials for the treatment of heart failure and hypertension. YM435 may be useful in the preservation of renal function in ischemia-induced acute renal failure. Also, it might be a useful as therapeutic agent for the treatment of congestive heart failure.

Terguride (INN), also known as trans-dihydrolisuride, is a serotonin receptor antagonist and dopamine receptor agonist of the ergoline family. Terguride is approved for and used in the treatment of hyperprolactinemia. Terguride is an oral, potent antagonist of 5-HT2B and 5-HT2A (serotonin) receptors. Serotonin stimulates the proliferation of pulmonary artery smooth muscle cells and induces fibrosis in the wall of pulmonary arteries. Together, this causes vascular remodeling and narrowing of the pulmonary arteries. These changes result in increased vascular resistance and PAH. Due to the potential anti-proliferative and anti-fibrotic activity of terguride, this potential medicine could offer the hope of achieving reversal of pulmonary artery vascular remodeling and attenuation of disease progression. In May 2008, terguride was granted orphan drug status for the treatment of pulmonary arterial hypertension. In May 2010 Pfizer purchased worldwide rights for the drug.

Spiperone (Spiroperidol; brand name: Spiropitan (JP)) is a typical antipsychotic and research chemical belonging to the butyrophenone chemical class. Spiperone is selective D2 dopamine receptor antagonist; α1B-adrenoceptor antagonist; mixed 5-HT2A/5-HT1 serotonin receptor antagonist. Additionally, spiperone was identified by compound screening to be an activator of Ca2+ activated Cl− channels (CaCCs), thus a potential target for therapy of cystic fibrosis. Spiperone is widely used as a pharmacological tool for studying neurotransmitter receptors.

Perospirone (Lullan®) is an atypical antipsychotic of the azapirone family. It is used in Japan for the treatment of schizophrenia and acute cases of bipolar mania. Its primary mode of action is through antagonism of serotonin 5-HT2A and dopamine D2 receptors.

Docarpamine (marketed under the tradename Tanadopa) is a dopamine prodrug developed in Japan for the treatment of chronic heart failure. The drug does not cross the blood-brain barrier and shows no effect on CNS activity. It is supposed that the drug exerts its action by activating dopamine receptor D1.

Metopimazine, a phenothiazine derivative, is a dopamine D2 receptor antagonist. It exerts its antiemetic effects via the chemoreceptor trigger zone. Metopimazine showed potent alpha-adrenergic blocking activity, showed histamine H1 antagonism, and induced palpebral ptosis. Metopimazine can occasionally be associated with orthostatic hypotension, which probably relates to its affinity for the α1-adrenoceptor. Therapeutic doses of metopimazine are likely to produce sedation and side-effects related to autonomic blockade. Metopimazine (Vogalene®) is indicated for the prevention and treatment of nausea and vomiting.

Piribedil is an antiparkinsonian agent which acts as D2 and D3 receptor agonist. In European countries and worldwide it is used as a monotherapy or in combination with dopatherapy for treatment of Parkinson's disease, cognitive impairment and obliterating arteriopathy.