Phentermine and topiramate and Prochlorperazine interaction

Phentermine and topiramate and Prochlorperazine: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.

Moderate

Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.

What the FDA labels say

From the Phentermine and topiramate label · effective 2026-05-18

Moderate

The concomitant use of alcohol or central nervous system (CNS) depressant drugs with phentermine and topiramate extended-release capsules may potentiate CNS depression or other centrally mediated effects of these agents, such as dizziness, cognitive adverse reactions, drowsiness, light-headedness, impaired coordination, and somnolence.

Warnings and precautionsby drug classView label on DailyMed
Moderate

CNS Depressants Including Alcohol Clinical Impact The concomitant use of alcohol or CNS depressant drugs (e.g., barbiturates, benzodiazepines, and sleep medications) with phentermine or topiramate may potentiate CNS depression such as dizziness or cognitive adverse reactions, or other centrally mediated effects of these agents.

Drug interactionsby drug classView label on DailyMed
Moderate

CNS Depressants Including Alcohol : May potentiate CNS depressant effects.

Drug interactionsby drug classView label on DailyMed

From the Prochlorperazine (PROCHLORPERAZINE MALEATE) label · effective 2025-07-09

Moderate

Phenothiazines may lower the convulsive threshold; dosage adjustments of anticonvulsants may be necessary.

Precautionsby drug classView label on DailyMed
Minor

Potentiation of anticonvulsant effects does not occur.

Precautionsby drug classView label on DailyMed

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Not 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.