Does Methotrexate Interact with Furosemide Benzalkonium Chloride?
Methotrexate and Furosemide Benzalkonium Chloride have a moderate drug interaction according to U.S. FDA drug labeling data. Methotrexate and other drugs undergoing significant renal tubular secretion may reduce the effect of furosemide and furosemide may decrease renal elimination of these drugs, potentially causing toxicity. The mechanism involves competition for renal tubular secretion. 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
- Methotrexate Class
- Folate Analog Metabolic Inhibitor
- Management
- Monitor for effects
- Data Source
- U.S. FDA via OpenFDA
How This Interaction Works
The interaction between Methotrexate and Furosemide Benzalkonium Chloride occurs because competition for renal tubular secretion. Clinically, this means methotrexate and other drugs undergoing significant renal tubular secretion may reduce the effect of furosemide and furosemide may decrease renal elimination of these drugs, potentially causing toxicity. 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 Methotrexate and your doctor is considering prescribing Furosemide Benzalkonium Chloride (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