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.

Raclopride is a salicylamide neuroleptic, that acts as a selective antagonist of D2 dopamine receptors both in vitro and in vivo. Tritium-labelled raclopride has properties that demonstrate its usefulness as a radioligand for the labelling of dopamine-D2 receptors : 3H-Raclopride has a high affinity for the rat and human dopamine-D2 receptors, the non-specific binding of 3H-raclopride is very low, not exceeding 5% of the total binding and the distribution of the 3H-raclopride binding sites in the brain closely correlates with the dopaminergic innervation. The binding of 3H-raclopride is blocked by dopamine-D2 agonists and antagonists, while the D1 agonist SKF 38393 and the Dl antagonist SCH 23390 have much less potency. The interaction of dopamine with 3H-raclopride binding results in a shallow competition curve, which suggests that 3H-raclopride, similar to other dopamine-D2 radioligands, labels both high and low agonist affinity states of the dopamine-D2 receptor. The in vivo receptor binding studies performed with 3H-raclopride also demonstrate its favorable properties as a dopamine-D2 receptor marker in vivo In contrast to some other compounds used as radioligands, raclopride enters the brain readily and binds with a low component of non-specific binding in all dopamine-rich brain areas. A saturation curve may be achieved in vivo binding studies since injections of increasing concentrations of 3H-raclopride appears to be saturated at concentrations above 25 mkCi (corresponding to approximately 5 nmol/kg). Raclopride antagonizes apomorphine-induced hyperactivity in the rat at low doses (ED50 = 130 nM/kg i.p.) but induces catalepsy only at much higher doses (ED50 = 27 mkM/kg i.p.). Radiolabelled raclopride has been used as a ligand for in vitro and in vivo autoradiography in rat and primate brains. Raclopride C 11 is used with positron emission tomography (PET) as a clinical research tool to determine dopamine type 2 (D 2) receptor density in the human brain under normal and pathological conditions. For example, raclopride C 11 used in PET studies has served to confirm the age-related decrease in striatal dopamine D2 receptor density, which may be associated with a decline in the motor as well as cognitive functions. In patients with Alzheimer's disease, raclopride C 11 may be used to examine neuroreceptor distribution and quantities, which may help in the analysis of degenerative alterations of neuron populations and neuroreceptor systems in patients with this disease. In Huntington's disease, in which degeneration of neostriatal interneurons occurs (postsynaptic to the dopaminergic input), specific binding of raclopride C 11 to D 2 receptors may serve as one of the parameters in predicting performance in cognitive tasks.

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.

Mosapramine (Cremin) is used to treat chronic schizophrenia in Japan. It is a potent dopamine antagonist with high affinity to the dopamine receptor subtypes 2, 3 and 4, and with moderate affinity for the 5-HT2 receptors

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.

Lisuride (DOPERGIN®), a highly active dopaminergic ergot derivative with prolactin-lowering properties, has a pronounced affinity for dopamine receptors. It may also act as an agonist at some serotonin receptors. Lisuride (DOPERGIN®) is concentrated within the pituitary where it acts on dopamine receptors which inhibit prolactin release. It can be used in the clinical conditions where a dopaminergic or prolactin-lowering effect is needed.

Perlapine ‎is a sedative and hypnotic drug.The drug brand named Hypnodin contains generic salt-Perlapine and is manufactured by Takeda Pharmaceutical. Perlapine is a potent H1R inverse agonist. It showed robust sedative effects clinically. Perlapine belongs to antipsychotic drugs which elicit little or no Parkinsonism, it binds more loosely than dopamine to D2 receptors.

Flibanserin is the first drug to be approved for hypoactive sexual desire disorder (HSDD) in premenopausal women by the FDA in August 2015. It was originally developed as an antidepressant medication by Boehringer Ingelheim, but showed lack of efficacy in trials and was further developed as a hypoactive sexual disorder drug by Sprout Pharmaceuticals. Flibanserin's mechanism of action is attributed to its high affinity for 5-HTA1 and 5-HTA2 receptors, displaying agonist activity on 5-HTA1 and antagonist on 5-HTA2, resulting in lowering of serotonin in the brain as well as an effect on increasing norepinephrine and dopamine neurotransmitters. Flibansetrin has high affinity for serotonin receptors in the brain: it acts as an agonist on 5-HT1A and an antagonist on 5-HT2A. In vivo, flibanserin binds equally to 5-HT1A and 5-HT2A receptors. However, under higher levels of brain 5-HT (i.e., under stress), flibanserin may occupy 5-HT2A receptors in higher proportion than 5-HT(1A) receptors. It may also moderately antagonize D4 (dopamine) receptors and 5-HT2B and 5-HTB2C. Its action on neurotransmitter receptors may contribute to reduction in serotonin levels and increase in dopamine and norepinephrine levels, all of which may play part in reward processing. Flibanserin is sold under the trade name Addyi and indicated for the treatment of premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD) as characterized by low sexual desire that causes marked distress or interpersonal difficulty.

Rotigotine is an agonist at all 5 dopamine receptor subtypes (D1-D5) but binds to the D3 receptor with the highest affinity. It is also an antagonist at α-2-adrenergic receptors and an agonist at the 5HT1A receptors. Rotigotine also inhibits dopamine uptake and prolactin secretion. It is FDA approved for the treatment of Parkinson's disease, restless legs syndrome. Dopamine antagonists, such as antipsychotics or metoclopramide, may diminish the effectiveness of Rotigotine. Common adverse reactions include nausea, vomiting, somnolence, application site reactions, dizziness, anorexia, hyperhidrosis, insomnia and dyskinesia.