Drug interactions
Primaquine + Venlafaxine
Severity: Moderate
Primaquine and Venlafaxine: 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
Venlafaxine has been linked to QT prolongation, particularly in overdose, and primaquine may also lengthen the QT interval. Combined use may add to arrhythmia risk in susceptible patients.
What this interaction means in plain words
Primaquine and Venlafaxine 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.
Primaquine belongs to Anti Parasitic; Venlafaxine belongs to Central Nervous System.
Why it happens
Additive pharmacodynamic QT prolongation.
What to do
Obtain a baseline ECG in patients with cardiac disease or other QT risk factors. Correct potassium and magnesium abnormalities and monitor the QTc.
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 Primaquine
- Pimozide + Primaquine Contraindicated
- Amiodarone + Primaquine Major
- Amisulpride + Primaquine Major
- Anagrelide + Primaquine Major
- Arsenic trioxide + Primaquine Major
- Asenapine + Primaquine Major
Other interactions of Venlafaxine
- Isocarboxazid + Venlafaxine Contraindicated
- Methylene blue + Venlafaxine Contraindicated
- Phenelzine + Venlafaxine Contraindicated
- Procarbazine + Venlafaxine Contraindicated
- Rasagiline + Venlafaxine Contraindicated
- Safinamide + Venlafaxine Contraindicated
Frequently asked questions
Can I take Primaquine with Venlafaxine?
MediHelp rates the interaction as moderate. Primaquine and Venlafaxine 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. Venlafaxine has been linked to QT prolongation, particularly in overdose, and primaquine may also lengthen the QT interval. Combined use may add to arrhythmia risk in susceptible patients.
How serious is the interaction between Primaquine and Venlafaxine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG in patients with cardiac disease or other QT risk factors. Correct potassium and magnesium abnormalities and monitor the QTc.
What other medicines interact with Primaquine?
MediHelp also lists interactions of Primaquine with, for example, Pimozide, Amiodarone, Amisulpride. The full list is on the Primaquine page.
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