Carbamazepine and Chlorpromazine interaction
Carbamazepine and Chlorpromazine: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Carbamazepine (EQUETRO) label · effective 2025-08-19
CNS Depressants The concomitant use of EQUETRO and other CNS depressants can increase the risk of respiratory depression, profound sedation, hypotension, and syncope.
Increased Intraocular Pressure Carbamazepine has mild anticholinergic activity.
Consider reducing the dose of CNS depressants or EQUETRO when using these drugs concomitantly.
Cytochrome (CYP) 3A4 inhibitors, epoxide hydrolase inhibitors, CYP3A4 inducers, drugs metabolized by CYP1A2 or CYP3A4 (oral contraceptives, delavirdine, nefazodone), phenytoin, CNS depressants, lithium, chloroquine, mefloquine ( 7.1 , 7.2 , 7.3 )
CNS depressants include: alcohol, opioid analgesics, benzodiazepines, tricyclic antidepressants, sedative/hypnotics, anticonvulsants, antipsychotics, antihistamines, anticholinergics, alpha and beta blockers, general anesthetics, muscle relaxants, and illicit CNS depressants.
From the Chlorpromazine (Chlorpromazine Hydrochloride) label · effective 2026-02-02
Therefore, dosage of anticonvulsants, including barbiturates, should not be reduced if chlorpromazine is started.
Chlorpromazine may lower the convulsive threshold; dosage adjustments of anticonvulsants may be necessary.
Note: Chlorpromazine does not intensify the anticonvulsant action of barbiturates.
Potentiation of anticonvulsant effects does not occur.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.