Drug interactions
Azithromycin + Pimavanserin
Severity: Major
Azithromycin and Pimavanserin: major interaction.
Last updated Sources: UK SmPC
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 prolongs the QT interval and its labeling advises avoiding use with other QT-prolonging drugs. Azithromycin adds to this effect and may increase the risk of torsades de pointes.
What this interaction means in plain words
Azithromycin and Pimavanserin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Azithromycin belongs to Anti Bacterial; Pimavanserin belongs to Central Nervous System.
Why it happens
Additive QTc prolongation via inhibition of cardiac repolarizing currents.
What to do
Avoid the combination where possible and use a non-QT-prolonging antibiotic. If needed, monitor ECG and keep potassium and magnesium within normal range.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
- Azithromycin 200mg/5ml Powder for Oral Suspension - SmPC sections 4.3/4.5 (class statement: medicinal products known to prolong the QT interval; "Azithromycin should be used with caution in patients receiving medicinal products known to prolong the QT interval") — electronic medicines compendium (UK SmPC)
Other interactions of Azithromycin
- Azithromycin + Cisapride Contraindicated
- Azithromycin + Domperidone Contraindicated
- Azithromycin + Dronedarone Contraindicated
- Azithromycin + Pimozide Contraindicated
- Azithromycin + Piperaquine Contraindicated
- Azithromycin + Thioridazine 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 Azithromycin with Pimavanserin?
MediHelp rates the interaction as major. Azithromycin and Pimavanserin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Pimavanserin prolongs the QT interval and its labeling advises avoiding use with other QT-prolonging drugs. Azithromycin adds to this effect and may increase the risk of torsades de pointes.
How serious is the interaction between Azithromycin and Pimavanserin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination where possible and use a non-QT-prolonging antibiotic. If needed, monitor ECG and keep potassium and magnesium within normal range.
What other medicines interact with Azithromycin?
MediHelp also lists interactions of Azithromycin with, for example, Cisapride, Domperidone, Dronedarone. The full list is on the Azithromycin page.
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