Drug interactions
Carisoprodol + Phenobarbital
Severity: Major
Carisoprodol and Phenobarbital: 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
Phenobarbital adds to carisoprodol's sedative effects and may also induce CYP2C19, lowering carisoprodol levels while raising meprobamate formation. Overall CNS depression may be increased.
What this interaction means in plain words
Carisoprodol 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 GABAergic CNS depression, plus CYP enzyme induction by phenobarbital.
What to do
Avoid if feasible; if used together, monitor sedation and respiratory status and adjust the carisoprodol dose.
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 Carisoprodol 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.
References
Other interactions of Carisoprodol
Frequently asked questions
Can I take Carisoprodol with Phenobarbital?
MediHelp rates the interaction as major. Carisoprodol 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 adds to carisoprodol's sedative effects and may also induce CYP2C19, lowering carisoprodol levels while raising meprobamate formation. Overall CNS depression may be increased.
How serious is the interaction between Carisoprodol 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: Avoid if feasible; if used together, monitor sedation and respiratory status and adjust the carisoprodol dose.
What other medicines interact with Carisoprodol?
MediHelp also lists interactions of Carisoprodol with, for example, Alfentanil, Alprazolam, Amobarbital. The full list is on the Carisoprodol 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.
