Table 22. Typical (D2 Antagonist) Antipsychotics: Overview.
| Efficacy | Schizophrenia (positive symptoms) (FDA-approved indication) |
| Tourette’s disorder (pimozide; FDA-approved indication) | |
| Mania (FDA-approved indication for chlorpromazine only) | |
| Psychotic depression (with antidepressant) | |
| Drug-induced psychosis | |
| Agitation,a nausea, hiccups (not FDA approved for these purposes; off-label) | |
| Side effects | EPS (more common in high-potency drugs) |
| NMS (rare) | |
| Dry mouth, constipation, urinary retention, sedation, weight gain (more common in low-potency drugs) | |
| Skin and eye complications QT interval prolongation (thioridazine) | |
| Dosage and administration | Individualize dosing. |
| 50–150 mg chlorpromazine equivalents (see Table 4–2) to start, with maximum total daily dose of 300–600 mg chlorpromazine equivalents (e.g., 6–12 mg haloperidol). | |
| Safety in overdose | CNS depression, hypotension, ECG changes, EPS. Manage with vital sign support, gastric lavage. Do not induce emesis secondary to aspiration risk. |
| Drug interactions | CNS depressants: ↑ sedation |
| Antacids: ↓ antipsychotic absorption | |
| Carbamazepine: ↓ antipsychotic levels | |
| SSRIs: ↑ antipsychotic levels | |
| Nicotine: ↓ antipsychotic levels | |
| Meperidine: ↑ sedation, hypotension | |
| β-Blockers: ↑ hypotension; may ↑ antipsychotic and β -blocker levels | |
| TCAs: may ↑ antipsychotic and TCA levels | |
| Valproic acid: chlorpromazine may ↑ valproic acid levels |
Note: CNS = central nervous system; ECG = electrocardiogram; EPS = extrapyramidal symptoms; FDA = U.S. Food and Drug Administration; NMS = neuroleptic malignant syndrome; SSRI = selective serotonin reuptake inhibitor; TCA = tricyclic antidepressant.
aAgitation associated with psychosis: FDA-approved indication for intramuscular olanzapine only.