Drug interactions
Clarithromycin + Iloperidone
Severity: Major
Clarithromycin and Iloperidone: major interaction.
Last updated Sources: Health Canada product monograph
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
Iloperidone is metabolized by CYP3A4 and CYP2D6, and clarithromycin is a strong CYP3A4 inhibitor that raises iloperidone exposure. Both drugs also prolong the QT interval, so the combination increases the risk of serious ventricular arrhythmias.
What this interaction means in plain words
Clarithromycin and Iloperidone 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.
Clarithromycin belongs to Anti Bacterial; Iloperidone belongs to Central Nervous System.
Why it happens
Clarithromycin inhibits CYP3A4 and P-gp-mediated clearance of iloperidone, and both drugs additively prolong the QT interval.
What to do
Reduce the iloperidone dose by about half while clarithromycin is given, and restore it after the antibiotic is stopped. Monitor ECG and electrolytes, or use a non-interacting antibiotic.
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
Other interactions of Clarithromycin
- Astemizole + Clarithromycin Contraindicated
- Avanafil + Clarithromycin Contraindicated
- Cisapride + Clarithromycin Contraindicated
- Clarithromycin + Colchicine Contraindicated
- Clarithromycin + Conivaptan Contraindicated
- Clarithromycin + Dihydroergotamine Contraindicated
Other interactions of Iloperidone
- Iloperidone + Thioridazine Contraindicated
- Alfuzosin + Iloperidone Major
- Amiodarone + Iloperidone Major
- Amisulpride + Iloperidone Major
- Amitriptyline + Iloperidone Major
- Anagrelide + Iloperidone Major
Frequently asked questions
Can I take Clarithromycin with Iloperidone?
MediHelp rates the interaction as major. Clarithromycin and Iloperidone 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. Iloperidone is metabolized by CYP3A4 and CYP2D6, and clarithromycin is a strong CYP3A4 inhibitor that raises iloperidone exposure. Both drugs also prolong the QT interval, so the combination increases the risk of serious ventricular arrhythmias.
How serious is the interaction between Clarithromycin and Iloperidone?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Reduce the iloperidone dose by about half while clarithromycin is given, and restore it after the antibiotic is stopped. Monitor ECG and electrolytes, or use a non-interacting antibiotic.
What other medicines interact with Clarithromycin?
MediHelp also lists interactions of Clarithromycin with, for example, Astemizole, Avanafil, Cisapride. The full list is on the Clarithromycin page.
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