Selected Anticoagulants (Vit K antagonists)/Metronidazole; Tinidazole Interactions
This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.
Serious. These medicines may interact and cause very harmful effects. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.
How the interaction occurs:
When these two medicines are taking together, your body may not process your blood-clot prevention medicine(e.g. warfarin) properly.
What might happen:
You may experience an increased chance for bleeding including bleeding from your gums, nosebleeds, unusual bruising, or dark stools.
What you should do about this interaction:
Make sure your healthcare professionals (e.g. doctor or pharmacist) know you are taking these two medicines together. They may already be aware of this interaction and may be monitoring you for it. If your doctor prescribes these medicines together, it may be necessary to check your blood test (e.g. INR) more often while you are taking both medicines and for a few days after you stop taking them together. The dose of your blood-clot prevention medicine may need adjusting.Do not start, stop, or change the dosage of any medicine before checking with them first.
- 1.This information is based on or an extract from the UW Metabolism and Transport Drug Interaction Database (DIDB) Platform, Copyright University of Washington 1999-2019..
- 2.Dean RP, Talbert RL. Bleeding associated with concurrent warfarin and metronidazole therapy. Drug Intell Clin Pharm 1980 Dec;14:864-6.
- 3.Kazmier FJ. A significant interaction between metronidazole and warfarin. Mayo Clin Proc 1976 Dec;51(12):782-4.
- 4.O'Reilly RA. The stereoselective interaction of warfarin and metronidazole in man. N Engl J Med 1976 Aug 12;295(7):354-7.
- 5.Yacobi A, Lai CM, Levy G. Pharmacokinetic and pharmacodynamic studies of acute interaction between warfarin enantiomers and metronidazole in rats. J Pharmacol Exp Ther 1984 Oct;231(1):72-9.
- 6.Tinidazole US prescribing information. Rising Pharmaceuticals, Inc.. October 12, 2017.
- 7.Johnson JA, Gong L, Whirl-Carrillo M, Gage BF, Scott SA, Stein CM, Anderson JL, Kimmel SE, Lee MT, Pirmohamed M, Wadelius M, Klein TE, Altman RB. Clinical Pharmacogenetics Implementation Consortium Guidelines for CYP2C9 and VKORC1 genotypes and warfarin dosing. Clin Pharmacol Ther 2011 Oct;90(4):625-9.
CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.