Drug interactions
Paroxetine + Pimavanserin
Severity: Moderate
Paroxetine and Pimavanserin: 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
Pimavanserin is a serotonin 5-HT2A inverse agonist that prolongs the QT interval, and paroxetine has a weak QT effect and serotonergic activity. Combining them could add to QT risk and rarely to serotonergic toxicity. Paroxetine's CYP2D6 inhibition is not expected to alter pimavanserin significantly, since it is metabolized mainly by CYP3A4.
What this interaction means in plain words
Paroxetine and Pimavanserin 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.
Paroxetine belongs to Central Nervous System; Pimavanserin belongs to Central Nervous System.
Why it happens
Possible additive QT prolongation and serotonergic pharmacodynamic effects.
What to do
Check baseline ECG and electrolytes and monitor for serotonin toxicity or QT-related symptoms. Avoid adding further QT-prolonging drugs.
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 Paroxetine
- Isocarboxazid + Paroxetine Contraindicated
- Methylene blue + Paroxetine Contraindicated
- Paroxetine + Phenelzine Contraindicated
- Paroxetine + Pimozide Contraindicated
- Paroxetine + Procarbazine Contraindicated
- Paroxetine + Selegiline Contraindicated
Other interactions of Pimavanserin
- Lefamulin + Pimavanserin Contraindicated
- Pimavanserin + Pimozide Contraindicated
- Pimavanserin + Vandetanib Contraindicated
- Adagrasib + Pimavanserin Major
- Amiodarone + Pimavanserin Major
- Amisulpride + Pimavanserin Major
Frequently asked questions
Can I take Paroxetine with Pimavanserin?
MediHelp rates the interaction as moderate. Paroxetine and Pimavanserin 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. Pimavanserin is a serotonin 5-HT2A inverse agonist that prolongs the QT interval, and paroxetine has a weak QT effect and serotonergic activity. Combining them could add to QT risk and rarely to serotonergic toxicity. Paroxetine's CYP2D6 inhibition is not expected to alter pimavanserin significantly, since it is metabolized mainly by CYP3A4.
How serious is the interaction between Paroxetine and Pimavanserin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check baseline ECG and electrolytes and monitor for serotonin toxicity or QT-related symptoms. Avoid adding further QT-prolonging drugs.
What other medicines interact with Paroxetine?
MediHelp also lists interactions of Paroxetine with, for example, Isocarboxazid, Methylene blue, Phenelzine. The full list is on the Paroxetine page.
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