Drug interactions
Perphenazine + Phendimetrazine
Severity: Moderate
Perphenazine and Phendimetrazine: 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
Phendimetrazine is a sympathomimetic anorectic that increases heart rate and blood pressure, whereas perphenazine is sedating, can prolong the QT interval and may lower the seizure threshold. The drugs have opposing CNS effects, and combined use could increase the risk of arrhythmia. Antipsychotics may also reduce the anorectic effect.
What this interaction means in plain words
Perphenazine and Phendimetrazine 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
Opposing pharmacodynamic effects with possible additive cardiovascular stress; mechanism not firmly established.
What to do
Monitor heart rate, blood pressure and ECG if clinically indicated. Consider alternatives to the stimulant in patients with cardiac risk factors or psychosis.
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 Phendimetrazine?
MediHelp rates the interaction as moderate. Perphenazine and Phendimetrazine 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. Phendimetrazine is a sympathomimetic anorectic that increases heart rate and blood pressure, whereas perphenazine is sedating, can prolong the QT interval and may lower the seizure threshold. The drugs have opposing CNS effects, and combined use could increase the risk of arrhythmia. Antipsychotics may also reduce the anorectic effect.
How serious is the interaction between Perphenazine and Phendimetrazine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor heart rate, blood pressure and ECG if clinically indicated. Consider alternatives to the stimulant in patients with cardiac risk factors or psychosis.
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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