14.5: Antipsychotic Drugs: Therapeutic Uses and Side Effects

Antipsychotic drugs primarily block dopamine and serotonin receptors and cholinergic, adrenergic, and histaminergic receptors, thereby reducing hallucinations and delusions in conditions like schizophrenia. However, they can trigger unwanted extrapyramidal effects such as dystonias, Parkinson-like symptoms, and tardive dyskinesia.

Despite these side effects, antipsychotics are used therapeutically for various purposes, including managing schizophrenia, preventing nausea and vomiting, curbing agitated behavior, and treating intractable hiccups and motor tics in Tourette disorder and autism. Second-generation antipsychotics, specifically clozapine (Clorazil), have shown efficacy in mitigating the negative symptoms of treatment-resistant schizophrenia. Nevertheless, antipsychotics also carry the risk of adverse effects like drowsiness, confusion, dry mouth, constipation, and sexual dysfunction. They can also lead to severe complications like neuroleptic malignant syndrome and tardive dyskinesia, requiring careful use in patients with seizure disorders or dementia-related behavioral disturbances. Maintenance therapy is often recommended for recurrent psychotic episodes.

Beyond their primary uses, antipsychotics are used to treat bipolar disorder, psychomotor agitation, Parkinson's disease-associated psychosis, and to provide restfulness and pain relief in palliative care.

Antipsychotic drugs, or antipsychotics,  treat schizophrenia, autism symptoms, agitation, and even intractable hiccups and motor tics.

Their pharmacological action primarily blocks dopamine and serotonin receptors. Additionally, they exhibit activity at other receptors.

Dopamine receptor blockade by typical antipsychotics can cause unwanted extrapyramidal effects like dystonia, Parkinson-like symptoms, akathisia, and tardive dyskinesia.

Medullary D₂ receptor blockade by these drugs results in antiemetic effects.

Some patients may experience anticholinergic effects like blurred vision, dry mouth, confusion, and gastrointestinal and urinary tract smooth muscle inhibition.

Atypical antipsychotics are often preferred over typical antipsychotics due to their lower risk of extrapyramidal side effects. Clozapine, an atypical antipsychotic, helps remedy treatment-resistant schizophrenia.

Additionally, antipsychotics are used in bipolar disorder, psychomotor agitation, Parkinson's disease-associated psychosis, and nausea.