Drug interactions
Perphenazine + Quazepam
Severity: Moderate
Perphenazine and Quazepam: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Quazepam is a benzodiazepine hypnotic, and perphenazine is a sedating antipsychotic. Together they can cause excessive sedation, impaired coordination, falls and hypotension, with risk of respiratory depression at high doses.
What this interaction means in plain words
Perphenazine and Quazepam can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Additive CNS depression through GABA-A potentiation and histaminic, adrenergic and dopaminergic blockade.
What to do
Use the lowest effective quazepam dose and monitor sedation and psychomotor function. Counsel patients to avoid alcohol and driving until the response is known.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Perphenazine
- Ibutilide + Perphenazine Contraindicated
- Perphenazine + Pimozide Contraindicated
- Perphenazine + Thioridazine Contraindicated
- Adagrasib + Perphenazine Major
- Alfentanil + Perphenazine Major
- Amiodarone + Perphenazine Major
Frequently asked questions
Can I take Perphenazine with Quazepam?
MediHelp rates the interaction as moderate. Perphenazine and Quazepam can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Quazepam is a benzodiazepine hypnotic, and perphenazine is a sedating antipsychotic. Together they can cause excessive sedation, impaired coordination, falls and hypotension, with risk of respiratory depression at high doses.
How serious is the interaction between Perphenazine and Quazepam?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use the lowest effective quazepam dose and monitor sedation and psychomotor function. Counsel patients to avoid alcohol and driving until the response is known.
What other medicines interact with Perphenazine?
MediHelp also lists interactions of Perphenazine with, for example, Ibutilide, Pimozide, Thioridazine. The full list is on the Perphenazine page.
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