Does Dextromethorphan Hydrobromide And Quinidine Sulfate Interact with Codeine?
Dextromethorphan Hydrobromide And Quinidine Sulfate and Codeine have a major drug interaction according to U.S. FDA drug labeling data. Quinidine-mediated inhibition of CYP2D6 may prevent conversion to active metabolite morphine, reducing analgesic/antitussive effects. The mechanism involves cyp2d6 inhibition prevents prodrug activation. 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
- Major
- Management
- Close medical supervision required
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Dextromethorphan Hydrobromide And Quinidine Sulfate and Codeine occurs because cyp2d6 inhibition prevents prodrug activation. Clinically, this means quinidine-mediated inhibition of cyp2d6 may prevent conversion to active metabolite morphine, reducing analgesic/antitussive effects. This is classified as a major interaction, meaning it could cause serious harm if not properly managed. Your healthcare provider may need to adjust dosages, substitute one medication, or increase monitoring frequency.
What To Tell Your Doctor or Pharmacist
If you are taking Dextromethorphan Hydrobromide And Quinidine Sulfate and your doctor is considering prescribing Codeine (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 how frequently you should be monitored while these are co-prescribed
- Ask whether any dosage adjustments are needed
- Never stop or change either medication without first consulting your healthcare provider