Does Cimetidine Interact with Venlafaxine?
CDI records a moderate classification for Cimetidine and Venlafaxine. The stored summary is: Cimetidine inhibits first-pass metabolism of venlafaxine, reducing oral clearance by 43% and increasing AUC and Cmax by 60%. Caution advised for patients with hypertension, elderly patients, or those with hepatic dysfunction. The mechanism involves inhibition of first-pass 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
- Moderate
- Cimetidine Class
- Histamine-2 Receptor Antagonist
- Management
- Monitor for effects
- Data Source
- U.S. FDA via OpenFDA
Recorded Mechanism
Inhibition of first-pass metabolism
What To Tell Your Doctor or Pharmacist
If you are taking Cimetidine and your doctor is considering prescribing Venlafaxine (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