D2 antagonists

Metoclopramide is a medication used to treat nausea, vomiting, gastroparesis, and gastroesophageal reflux disease. It is also used to treat migraine headaches.

Olanzapine, sold under the brand name Zyprexa among others, is an atypical antipsychotic primarily used to treat schizophrenia and bipolar disorder. It is also sometimes used off-label in cancer patients for treatment of chemotherapy-induced nausea and vomiting and as an appetite stimulant. For schizophrenia, it can be used for both new-onset disease and long-term maintenance. It is taken by mouth or by injection into a muscle.

Hydroxyzine, sold under the brand names Atarax and Vistaril among others, is an antihistamine medication. It is used in the treatment of itchiness, anxiety, insomnia, and nausea (including that due to motion sickness). It is used either by mouth or injection into a muscle.

alt=A box of aripiprazole 15 mg tablets.|thumb|Aripiprazole 15 mg tablets Aripiprazole, sold under the brand name Abilify, among others, is a unique atypical antipsychotic primarily used in the treatment of schizophrenia, mania in bipolar disorder, and irritability associated with autism spectrum disorder (in children and adolescents aged 6 to 17 years); other uses include as an add-on treatment for major depressive disorder, obsessive–compulsive disorder, and tic disorders. Aripiprazole is taken by mouth or via injection into a muscle.

Buspirone, sold under the name Buspar among others, is an anxiolytic medication primarily used for the treatment of generalized anxiety disorder. Unlike benzodiazepines, buspirone does not produce significant sedation, dependence, or withdrawal symptoms.

Imipramine, sold under the brand name Tofranil, among others, is a tricyclic antidepressant (TCA) mainly used in the treatment of depression. It is also effective in treating anxiety and panic disorder. Imipramine is taken by mouth.

Doxepin is a medication belonging to the tricyclic antidepressant (TCA) class of drugs used to treat major depressive disorder, anxiety disorders, difficult-to-treat chronic urticaria, and insomnia. For hives it is a less preferred alternative to antihistamines. It has a mild to moderate benefit for sleeping problems. It is used as a cream for itchiness due to atopic dermatitis or lichen simplex chronicus.

Amisulpride, sold under the brand names Socian 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.

Pimozide (sold under the brand name Orap) is a neuroleptic drug of the diphenylbutylpiperidine class. It was discovered at Janssen Pharmaceutica in 1963. It has a high potency compared to chlorpromazine (ratio 50-70:1). On a weight basis it is even more potent than haloperidol. It also has special indication for Tourette syndrome and resistant tics.

Chlorprothixene, sold under the brand name Truxal among others, is a typical antipsychotic of the thioxanthene group.

Tiotixene, or thiothixene, is a typical antipsychotic sold under the brand name Navane which is predominantly utilised to treat schizophrenia. Beyond its primary indication, it can exhibit a variety of effects common to neuroleptic drugs including anxiolytic, anti-depressive, and anti-aggressive properties.

Flunarizine, sold under the brand name Sibelium among others, is a drug classified as a calcium antagonist which is used for various indications. It is not available by prescription in the United States or Japan. The drug was discovered at Janssen Pharmaceutica (R14950) in 1968.

Molindone, sold under the brand name Moban, is an antipsychotic medication which is used in the United States in the treatment of schizophrenia. It is taken by mouth.

Pipamperone (INN, USAN, BAN), sold under the brand name Dipiperon, is a typical antipsychotic of the butyrophenone family used in the treatment of schizophrenia and as a sleep aid for depression. It is or has been marketed under brand names including Dipiperon, Dipiperal, Piperonil, Piperonyl, and Propitan. Pipamperone was discovered at Janssen Pharmaceutica in 1961, and entered clinical trials in the United States in 1963.

Opipramol, sold under the brand name Insidon among others, is an anxiolytic and tricyclic antidepressant that is used throughout Europe. Despite chemically being a tricyclic dibenzazepine (iminostilbene) derivative similar to imipramine, opipramol is not a monoamine reuptake inhibitor like most other tricyclic antidepressants, and instead acts primarily as a sigma-1 receptor agonist. It was developed by Schindler and Blattner in 1961.

Blonanserin, sold under the brand name Lonasen, is a relatively new atypical antipsychotic (approved by PMDA in January 2008) commercialized by Dainippon Sumitomo Pharma in Japan and Korea for the treatment of schizophrenia. Relative to many other antipsychotics, blonanserin has an improved tolerability profile, lacking side effects such as extrapyramidal symptoms, excessive sedation, or hypotension. As with many second-generation (atypical) antipsychotics it is significantly more efficacious in the treatment of the negative symptoms of schizophrenia compared to first-generation (typical) anti

Spiperone, also known as spiroperidol and sold under the brand name Spiropitan ((JP)) is a typical antipsychotic of the butyrophenone family related to haloperidol. It is approved for clinical use in Japan as a treatment for schizophrenia.

Ketanserin, sold under the brand name Sufrexal, is an antihypertensive agent which is used to treat arterial hypertension and vasospastic disorders. It is also used in scientific research as an antiserotonergic agent in the study of the serotonin system; specifically, the 5-HT2 receptor family. The drug is taken orally.

Levosulpiride, sold under the brand names Dislep and Sulpepta among others, is a dopamine antagonist medication which is used in the treatment of psychotic disorders like schizophrenia, major depressive disorder, nausea and vomiting, and gastroparesis. It is taken by mouth.

Itopride (INN; brand name Ganaton) is a prokinetic benzamide derivative. These drugs inhibit dopamine and acetylcholine esterase enzyme and have a gastrokinetic effect. Itopride is indicated for the treatment of functional dyspepsia and other gastrointestinal conditions. It is a combined D2 receptor antagonist and acetylcholinesterase inhibitor. Itopride is the dimethoxy analog of trimethobenzamide.

Trimethobenzamide (trade names Tebamide, Tigan) is an antiemetic used to prevent nausea and vomiting.

Nemonapride, also previously known as emonapride and sold under the brand name Emilace, is an atypical antipsychotic which is used in the treatment of schizophrenia. It is taken by mouth.

Terguride (, ), sold under the brand name Teluron, is a serotonin receptor antagonist and dopamine receptor agonist of the ergoline family. It is approved for and used as a prolactin inhibitor in the treatment of hyperprolactinemia (high prolactin levels) in Japan. Terguride is taken by mouth.

Metopimazine (, , ), sold under the brand names Vogalen and Vogalene, is an antiemetic of the phenothiazine group which is used to treat nausea and vomiting. It is marketed in Europe, Canada, and South America. As of August 2020, metopimazine has been repurposed and is additionally under development for use in the United States for the treatment of gastroparesis.

Raclopride is a typical antipsychotic. It acts as a selective antagonist on D2 dopamine receptors. It has been used in trials studying Parkinson Disease.

(−)-Stepholidine is a protoberberine alkaloid found in the plant Stephania intermedia.

Tetrahydropalmatine (THP) is an isoquinoline alkaloid found in several different plant species, mainly in the genus Corydalis (Yan Hu Suo), but also in other plants such as Stephania rotunda. These plants have traditional uses in Chinese herbal medicine. The pharmaceutical industry has synthetically produced the more potent enantiomer Levo-tetrahydropalmatine (Levo-THP; technically l-THP, often written L-THP), which has been marketed worldwide under different brand names as an alternative to anxiolytic and sedative drugs of the benzodiazepine group and analgesics such as opiates. It is also so

Aceprometazine (INN) is a phenothiazine derivative prescription drug with neuroleptic and anti-histamine properties It is not widely prescribed, and may be associated with drug-induced Parkinsonism. It may be used in combination with meprobamate for the treatment of sleep disorders. This combination is available in France under the trade name Mepronizine.

Ocaperidone (R 79598) is a benzisoxazole antipsychotic. It was initially developed by Janssen, later licensed to French laboratory Neuro3D and then acquired in 2007 by German company Evotec. It was found to be more potent than risperidone in animal studies, but its testing was abandoned in 2010 after unfavorable results in human Phase II trials, as while it was effective at controlling symptoms of schizophrenia, ocaperidone produced an unacceptable amount of extrapyramidal side effects.

Pridopidine (developmental code name PL-101) is an orally administrated small molecule investigational drug. Pridopidine is a selective and potent sigma-1 receptor agonist. It is being developed by Prilenia Therapeutics and is currently in late-stage clinical development for Huntington's disease (HD) and amyotrophic lateral sclerosis (ALS).