Drug interactions
Lopinavir + Tolterodine
Severity: Major
Lopinavir and Tolterodine: major interaction.
Last updated Sources: US FDA label
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
Lopinavir boosted with ritonavir strongly inhibits CYP3A4 and raises tolterodine levels. This increases anticholinergic effects and QT risk.
What this interaction means in plain words
Lopinavir and Tolterodine 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.
Lopinavir belongs to Anti Virals; Tolterodine belongs to Genitourinary.
Why it happens
CYP3A4 inhibition by lopinavir/ritonavir reduces tolterodine clearance.
What to do
Limit tolterodine to 2 mg daily (1 mg twice daily immediate-release) and monitor for anticholinergic toxicity and QT prolongation.
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 Tolterodine
Other interactions of Lopinavir
- Alfuzosin + Lopinavir Contraindicated
- Avanafil + Lopinavir Contraindicated
- Cisapride + Lopinavir Contraindicated
- Dronedarone + Lopinavir Contraindicated
- Eletriptan + Lopinavir Contraindicated
- Eplerenone + Lopinavir Contraindicated
Frequently asked questions
Can I take Lopinavir with Tolterodine?
MediHelp rates the interaction as major. Lopinavir and Tolterodine 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. Lopinavir boosted with ritonavir strongly inhibits CYP3A4 and raises tolterodine levels. This increases anticholinergic effects and QT risk.
How serious is the interaction between Lopinavir and Tolterodine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Limit tolterodine to 2 mg daily (1 mg twice daily immediate-release) and monitor for anticholinergic toxicity and QT prolongation.
What other medicines interact with Tolterodine?
MediHelp also lists interactions of Tolterodine with, for example, Clarithromycin, Clozapine, Cobicistat. The full list is on the Tolterodine page.
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