Does Famciclovir Interact with Probenecid?
Famciclovir and Probenecid have a moderate drug interaction according to U.S. FDA drug labeling data. May increase penciclovir levels. Monitor for evidence of penciclovir toxicity. The mechanism involves probenecid is significantly eliminated by active renal tubular secretion and may reduce penciclovir 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
- Moderate
- Famciclovir Class
- Herpes Simplex Virus Nucleoside Analog DNA Polymerase Inhibitor
- Management
- Monitor for effects
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Famciclovir and Probenecid occurs because probenecid is significantly eliminated by active renal tubular secretion and may reduce penciclovir clearance. Clinically, this means may increase penciclovir levels. monitor for evidence of penciclovir toxicity. This is classified as a moderate interaction. While it may not require stopping either medication, your healthcare provider should be aware you are taking both so they can monitor for potential effects and adjust treatment if necessary.
What To Tell Your Doctor or Pharmacist
If you are taking Famciclovir and your doctor is considering prescribing Probenecid (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
- Ask whether any dosage adjustments are needed
- Never stop or change either medication without first consulting your healthcare provider