A dopamine antagonist (antidopaminergic) 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.
Uses and examples
Dopamine receptor antagonists are used for some diseases such as schizophrenia, bipolar disorder, nausea and vomiting. It can also control the symptoms of hypersexuality and increased orgasmic activity.
Antidopaminergics such as haloperidol can be an antidote for poisoning with cocaine, amphetamines and dopamine agonists such as bromocriptine and/or ropinirole.
Agents such as atypical antipsychotics (coupled with serotonin antagonist effects): paliperidone, clozapine, risperidone, olanzapine, quetiapine, and ziprasidoneUsed as antiemetics: metoclopramide, droperidol, domperidoneUsed as tricyclic antidepressants: amoxapine, clomipramine, trimipramineCholine can antagonize dopamine directly or interfere with receptor functionMelatonin suppresses dopamine activity as part of normal circadian rhythm functions, although pathological imbalances have been implicated in Parkinson's diseaseThey may include one or more of the following and last indefinitely even after cessation of the dopamine antagonist, especially after long-term or high-dosage use:
Dysphoria and depressionExtrapyramidal symptoms, including:AkathisiaParkinsonism due to effects on the nigrostriatal pathwayTardive dyskinesia (long-term use)Galactorrhea due to removal of dopamine-mediated inhibition (D2 receptor antagonism) on the lactotrophic cells in the anterior pituitary preventing the release of prolactin.Hyperprolactinaemia due to effects on the tuberoinfundibular pathwayIncreased appetiteIrritability and aggressionLow libido, sexual dysfunction and impotence due to blockage of the pleasure center (dopaminergic pathways)Menstrual disorderMetabolic changes with increased risk of obesity and diabetes mellitus type 2Neuroleptic Induced Deficit Syndrome (long-term use)Paranoia (rare)Sedation or psychomotor agitationSymptoms similar to ADHDSymptoms similar to narcolepsyExamples of Dopamine antagonists include:
acepromazineamisulprideamoxapineasenapineazaperonebenperidolbromopridebutaclamolclomipramine (mild)chlorpromazinechlorprothixeneclopenthixoldomperidonedroperidoleticloprideflupenthixolfluphenazinefluspirilenehaloperidolhydroxyzineiodobenzamidelevomepromazineloxapinemesoridazinemetoclopramidenafadotridenemonaprideolanzapinepaliperidonepenfluridolperazineperphenazinepimozideprochlorperazinepromazinequetiapineracloprideremoxipriderisperidonespiperonespiroxatrinestepholidinesulpiridesultopridetetrahydropalmatinethiethylperazinethioridazinethiothixenetiapridetrifluoperazinetrifluperidoltriflupromazineziprasidone
