CriticalOpioid analgesic, phenylpiperidine class×HIV protease inhibitor / pharmacokinetic booster
Updated · Methodology
Mechanism
Ritonavir inhibits CYP3A4 (meperidine metabolism) while inducing formation of neurotoxic normeperidine. Seizure risk.
Symptoms
Seizures, delirium.
Management
Combination contraindicated. Alternative – fentanyl.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
Summary of a multi-drug list →
Medicine list: everything you take in one place →
Sources
- FDA: Demerol (meperidine) prescribing information (2017)– FDA Demerol label, boxed warning serotonergic
- AEMPS: Ficha técnica: Ritonavir (nº registro 81039), sección 4.3 (2025)– AEMPS, CIMA, nº registro 81039, revisión 04/2025, sección 4.3