Drug interactions
Chlorpromazine + Phentermine
Severity: Moderate
Chlorpromazine and Phentermine: 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
Phentermine is a sympathomimetic stimulant that can raise blood pressure and heart rate, whereas chlorpromazine is sedating, can lower blood pressure and may prolong the QT interval. The effects partly oppose each other and combined cardiac effects are unpredictable.
What this interaction means in plain words
Chlorpromazine and Phentermine 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.
Chlorpromazine belongs to Central Nervous System; Phentermine belongs to Central Nervous System.
Why it happens
Pharmacodynamic opposition with possible additive cardiovascular effects.
What to do
Monitor blood pressure, pulse and ECG where cardiac risk factors exist. Reassess whether both drugs are needed.
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 Chlorpromazine
- Chlorpromazine + Dofetilide Contraindicated
- Chlorpromazine + Dronedarone Contraindicated
- Chlorpromazine + Droperidol Contraindicated
- Chlorpromazine + Ibutilide Contraindicated
- Chlorpromazine + Metrizamide Contraindicated
- Chlorpromazine + Panobinostat Contraindicated
Other interactions of Phentermine
- Isocarboxazid + Phentermine Contraindicated
- Linezolid + Phentermine Contraindicated
- Phenelzine + Phentermine Contraindicated
- Phentermine + Procarbazine Contraindicated
- Phentermine + Rasagiline Contraindicated
- Phentermine + Selegiline Contraindicated
Frequently asked questions
Can I take Chlorpromazine with Phentermine?
MediHelp rates the interaction as moderate. Chlorpromazine and Phentermine 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. Phentermine is a sympathomimetic stimulant that can raise blood pressure and heart rate, whereas chlorpromazine is sedating, can lower blood pressure and may prolong the QT interval. The effects partly oppose each other and combined cardiac effects are unpredictable.
How serious is the interaction between Chlorpromazine and Phentermine?
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 blood pressure, pulse and ECG where cardiac risk factors exist. Reassess whether both drugs are needed.
What other medicines interact with Chlorpromazine?
MediHelp also lists interactions of Chlorpromazine with, for example, Dofetilide, Dronedarone, Droperidol. The full list is on the Chlorpromazine page.
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