Does Phenobarbital Interact with Granisetron Hydrochloride?
Phenobarbital and Granisetron Hydrochloride have a unknown drug interaction according to U.S. FDA drug labeling data. Hepatic enzyme induction with phenobarbital resulted in 25% increase in total plasma clearance of granisetron, but clinical significance is not known. The mechanism involves hepatic enzyme induction increasing clearance. Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This information is based on official FDA drug labeling sourced from OpenFDA and the NIH National Library of Medicine.
- Severity
- Unknown
- Management
- Consult your pharmacist
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Phenobarbital and Granisetron Hydrochloride occurs because hepatic enzyme induction increasing clearance. Clinically, this means hepatic enzyme induction with phenobarbital resulted in 25% increase in total plasma clearance of granisetron, but clinical significance is not known.
What To Tell Your Doctor or Pharmacist
If you are taking Phenobarbital and your doctor is considering prescribing Granisetron Hydrochloride (or vice versa), make sure to:
- Inform your doctor and pharmacist of all current medications, including over-the-counter drugs and supplements
- Ask whether the benefits of combining these medications outweigh the risks for your specific situation
- Ask what symptoms to watch for that would indicate the interaction is causing problems
- Never stop or change either medication without first consulting your healthcare provider