Does Clarithromycin Interact with Terfenadine?
CDI records a contraindicated classification for Clarithromycin and Terfenadine. The stored summary is: Concomitant administration is contraindicated. Clarithromycin increases plasma concentrations of terfenadine's active acid metabolite threefold. The mechanism involves clarithromycin inhibits terfenadine metabolism. Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This record was extracted from drug labeling through openFDA. NIH/NLM RxNorm is used for drug identities. The summary and severity classification are CDI's processed information, not a verbatim source quotation. Product, route, and patient circumstances matter.
- Severity
- Contraindicated
- Clarithromycin Class
- Macrolide Antimicrobial
- Management
- Do not take together
- Data Source
- U.S. FDA via OpenFDA
Recorded Mechanism
Clarithromycin inhibits terfenadine metabolism
What To Tell Your Doctor or Pharmacist
If you are taking Clarithromycin and your doctor is considering prescribing Terfenadine (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 about alternative medications that do not interact with your current regimen
- Ask how frequently you should be monitored while these are co-prescribed
- Never stop or change either medication without first consulting your healthcare provider