Does Metronidazole Interact with Tinidazole?
Metronidazole and Tinidazole have a major drug interaction according to U.S. FDA drug labeling data. 7 DRUG INTERACTIONS The following drug interactions were reported for metronidazole, a chemically-related nitroimidazole and may therefore occur with tinidazole: Warfarin and other oral coumarin anticoagulants: Anticoagulant dosage may need adjustment during and up to 8 days after tinidazole therapy ( 7.1 ) Alcohol-containing beverages/preparations: Avoid during and up to 3 days after tinidazole therapy ( 7.1 ) Lithium: Monitor serum lithium concentrations ( 7.1 ) Cyclosporine, tacrolimus: Monitor for toxicities of these immunosuppressive drugs ( 7.1 ) Fluorouracil: Monitor for fluorouracil-associated toxicities ( 7.1 ) Phenytoin, fosphenytoin: Adjustment of anticonvulsant and/or tinidazole dose(s) may be needed ( 7.1 , 7.2 ) CYP3A4 inducers/inhibitors: Monitor for decreased tinidazole effect or increased adverse reactions ( 7.2 ) Although not specifically identified in studies with tinidazole, the following drug interactions were reported for metronidazole, a chemically-related nitroimidazole. 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
- Metronidazole Class
- Nitroimidazole Antimicrobial
- Tinidazole Class
- Nitroimidazole Antimicrobial
- Management
- Close medical supervision required
- Data Source
- U.S. FDA via OpenFDA
What To Tell Your Doctor or Pharmacist
If you are taking Metronidazole and your doctor is considering prescribing Tinidazole (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