Drug interactions
Meperidine + Ritonavir
Severity: Major
Meperidine and Ritonavir: major 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
Ritonavir inhibits CYP3A4 and may alter meperidine metabolism. In practice ritonavir also induces other pathways, and labeling advises against use with meperidine because the normeperidine metabolite may accumulate, which can cause neurotoxicity including seizures.
What this interaction means in plain words
Meperidine and Ritonavir 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.
Meperidine belongs to Musculoskeletal; Ritonavir belongs to Anti Virals.
Why it happens
Altered CYP3A4/CYP2B6 mediated metabolism of meperidine, increasing exposure to the neurotoxic metabolite normeperidine.
What to do
Avoid concurrent use and choose an alternative analgesic such as one without active neurotoxic metabolites. If unavoidable, give short courses and monitor for sedation, tremor and seizures.
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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Other interactions of Meperidine
- Alvimopan + Meperidine Contraindicated
- Isocarboxazid + Meperidine Contraindicated
- Meperidine + Methylene blue Contraindicated
- Meperidine + Olanzapine / samidorphan Contraindicated
- Meperidine + Phenelzine Contraindicated
- Meperidine + Procarbazine Contraindicated
Other interactions of Ritonavir
- Alfuzosin + Ritonavir Contraindicated
- Amiodarone + Ritonavir Contraindicated
- Avanafil + Ritonavir Contraindicated
- Colchicine + Ritonavir Contraindicated
- Dronedarone + Ritonavir Contraindicated
- Eletriptan + Ritonavir Contraindicated
Frequently asked questions
Can I take Meperidine with Ritonavir?
MediHelp rates the interaction as major. Meperidine and Ritonavir 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. Ritonavir inhibits CYP3A4 and may alter meperidine metabolism. In practice ritonavir also induces other pathways, and labeling advises against use with meperidine because the normeperidine metabolite may accumulate, which can cause neurotoxicity including seizures.
How serious is the interaction between Meperidine and Ritonavir?
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 concurrent use and choose an alternative analgesic such as one without active neurotoxic metabolites. If unavoidable, give short courses and monitor for sedation, tremor and seizures.
What other medicines interact with Meperidine?
MediHelp also lists interactions of Meperidine with, for example, Alvimopan, Isocarboxazid, Methylene blue. The full list is on the Meperidine page.
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