Does Promethazine Interact with Zaleplon?
Promethazine and Zaleplon have a moderate drug interaction according to U.S. FDA drug labeling data. Co-administration resulted in 15% decrease in maximal zaleplon plasma concentrations with no change in AUC. Pharmacodynamics not evaluated; caution advised. The mechanism involves potential pharmacodynamic interaction; pharmacokinetic changes of minor significance. 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
- Zaleplon Class
- gamma-Aminobutyric Acid A Receptor Agonist
- Management
- Monitor for effects
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Promethazine and Zaleplon occurs because potential pharmacodynamic interaction; pharmacokinetic changes of minor significance. Clinically, this means co-administration resulted in 15% decrease in maximal zaleplon plasma concentrations with no change in auc. pharmacodynamics not evaluated; caution advised. 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 Promethazine and your doctor is considering prescribing Zaleplon (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