Chlorpromazine and Zonisamide interaction
Chlorpromazine and Zonisamide: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
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.
From the Zonisamide (ZONISADE) label · effective 2025-09-08
Caution should be used when ZONISADE is prescribed with other drugs that predispose patients to heat-related disorders; these drugs include, but are not limited to, carbonic anhydrase inhibitors and drugs with anticholinergic activity.
Patients should be carefully observed for signs of central nervous system (CNS) depression, such as somnolence and sedation, when ZONISADE is used with other drugs with sedative properties because of potential additive effects.
• ZONISADE should be used with caution if used in combination with alcohol or other CNS depressants ( 7.1 ).
CNS Depressants Concomitant use of ZONISADE with other CNS depressants, including alcohol, may increase the risk of CNS depression, as well as other cognitive and/or neuropsychiatric adverse events [see Warnings and Precautions ( 5.11 )] .
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.