Drug interactions
Meperidine + Phenobarbital
Severity: Major
Meperidine and Phenobarbital: 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
Phenobarbital and meperidine together produce additive sedation and respiratory depression. Phenobarbital also induces hepatic enzymes, which can increase conversion of meperidine to normeperidine, a metabolite that can cause tremor and seizures.
What this interaction means in plain words
Meperidine and Phenobarbital 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.
Why it happens
Additive CNS depression and CYP enzyme induction that increases normeperidine production.
What to do
Monitor sedation, respiratory rate and signs of normeperidine toxicity such as tremor or myoclonus. Prefer an opioid without active neurotoxic metabolites when prolonged use is required.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Meperidine and Phenobarbital, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Meperidine
- Alvimopan + Meperidine Contraindicated
- Isocarboxazid + Meperidine Contraindicated
- Meperidine + Methylene blue Contraindicated
- Meperidine + Olanzapine / samidorphan Contraindicated
- Meperidine + Phenelzine Contraindicated
- Meperidine + Procarbazine Contraindicated
Frequently asked questions
Can I take Meperidine with Phenobarbital?
MediHelp rates the interaction as major. Meperidine and Phenobarbital 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. Phenobarbital and meperidine together produce additive sedation and respiratory depression. Phenobarbital also induces hepatic enzymes, which can increase conversion of meperidine to normeperidine, a metabolite that can cause tremor and seizures.
How serious is the interaction between Meperidine and Phenobarbital?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor sedation, respiratory rate and signs of normeperidine toxicity such as tremor or myoclonus. Prefer an opioid without active neurotoxic metabolites when prolonged use is required.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
