Drug interactions
Dronabinol + Phenobarbital
Severity: Moderate
Dronabinol and Phenobarbital: moderate 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 induces CYP3A4 and CYP2C9, the main enzymes that metabolize dronabinol, and may lower its exposure. Additive sedation is also possible because both agents depress the CNS.
What this interaction means in plain words
Dronabinol and Phenobarbital can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Why it happens
Phenobarbital induces CYP2C9 and CYP3A4, and the two drugs have additive CNS depressant effects.
What to do
Monitor for reduced dronabinol effect and for sedation. Increase the dronabinol dose as needed and reassess if phenobarbital is stopped.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Dronabinol
- Cefotetan + Dronabinol Contraindicated
- Disulfiram + Dronabinol Contraindicated
- Dronabinol + Midazolam intranasal Major
- Dronabinol + Zuranolone Major
- Amobarbital + Dronabinol Moderate
- Apalutamide + Dronabinol Moderate
Frequently asked questions
Can I take Dronabinol with Phenobarbital?
MediHelp rates the interaction as moderate. Dronabinol and Phenobarbital can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Phenobarbital induces CYP3A4 and CYP2C9, the main enzymes that metabolize dronabinol, and may lower its exposure. Additive sedation is also possible because both agents depress the CNS.
How serious is the interaction between Dronabinol and Phenobarbital?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor for reduced dronabinol effect and for sedation. Increase the dronabinol dose as needed and reassess if phenobarbital is stopped.
What other medicines interact with Dronabinol?
MediHelp also lists interactions of Dronabinol with, for example, Cefotetan, Disulfiram, Midazolam intranasal. The full list is on the Dronabinol page.
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