Does Thiazides Interact with Mefenamic Acid?
Thiazides and Mefenamic Acid have a moderate drug interaction according to U.S. FDA drug labeling data. Mefenamic acid can reduce the natriuretic effect of thiazides. Patient should be observed for signs of renal failure and diuretic efficacy. The mechanism involves inhibition of renal prostaglandin synthesis. 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
- Mefenamic Acid Class
- Nonsteroidal Anti-inflammatory Drug
- Management
- Monitor for effects
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Thiazides and Mefenamic Acid occurs because inhibition of renal prostaglandin synthesis. Clinically, this means mefenamic acid can reduce the natriuretic effect of thiazides. patient should be observed for signs of renal failure and diuretic efficacy. 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 Thiazides and your doctor is considering prescribing Mefenamic Acid (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