First-generation antipsychotic, aliphatic-side-chain phenothiazine
ATC code: N05AA01 (Chlorpromazine)
Brand names
Thorazine
Blocks D2 receptors (antipsychotic effect), 5-HT2A, alpha-1 adrenoceptors (orthostatic hypotension, sedation), muscarinic M1 (dry mouth) and H1 (sedation). Clinically prolongs QT (10-20 ms). Metabolised by CYP2D6 + CYP1A2.
Third line
Chlorpromazine is third-line antipsychotic for schizophrenia. SEPB reserves it after atypical APs due to high rates of extrapyramidal symptoms, hyperprolactinaemia and QT prolongation. Also used in acute agitation and hiccup.
2 pairs found. Sorted from critical to minor.
Mechanism
Dual QT prolongation, additive hypotension (chlorpromazine alpha-1 block).
Symptoms
QTc above 500 ms, syncope, torsades de pointes risk.
Management
Combination contraindicated.
Mechanism
Additive QT prolongation.
Symptoms
QTc above 500 ms, syncope, torsades de pointes risk.
Management
Alternative – levofloxacin.
Opens the checker prefilled with this drug. Pick the second one from your regimen.
Third-trimester use linked to neonatal extrapyramidal symptoms and withdrawal.
Passes into breast milk. Breastfeeding not recommended.
Reference information, not a clinical decision. Discuss feeding pauses or changes with your physician or an IBCLC.
Chlorpromazine is evaluated for the following indications with varying evidence strength: Schizophrenia (evidence tier B). See the full indication matrix with dosing and citations above on this page.
Common side effects of Chlorpromazine (≥ 1 in 100): Sedation, Orthostatic hypotension, Extrapyramidal symptoms, Dry mouth, Weight gain. See the Safety section for uncommon and serious reactions.
FDA category C. Third-trimester use linked to neonatal extrapyramidal symptoms and withdrawal.
Passes into breast milk. Breastfeeding not recommended.
Chlorpromazine is contraindicated in: Coma, severe CNS depression; Combination with other QT-prolongers; Closed-angle glaucoma; Severe hepatic impairment. Full list in the Safety section.