Warfarin and Cefotetan Injection: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Warfarin
Cefotetan Injection
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
An increased risk of bleeding
Interaction Deep Dive
Marked hypoprothrombinemia and/or prolonged bleeding time is a complication with the concurrent use of warfarin and cefotetan, cefamandole, cefoperazone, or moxalactam1234.
Why it happens (mechanism)
Inhibition of platelet function, decreased clotting factor synthesis
Common questions
Can I take Warfarin and Cefotetan Injection together?
An increased risk of bleeding Always confirm with your pharmacist or prescriber before making any change.
How serious is the Warfarin and Cefotetan Injection interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "delayed". Effects tend to build up gradually over days to weeks.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
From our Q&A
Real reader questions about these medications, each personally answered by our pharmacist:
Questions for your pharmacist
- Does my dose of Warfarin or Cefotetan Injection need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (4)
- Custer GM, Briggs BR, & Smith RE: Effect of cefamandole nafate on blood coagulation and platelet function. Antimicrob Agents Chemother 1979; 16:869-872. PubMed
- Fainstein V, Bodey GP, MdCredie KB, et al: Coagulation abnormalities induced by beta-lactam antibiotics in cancer patients. J Infect Dis 1983; 148:745-750.
- Osborne JC: Hypoprothrombinemia and bleeding due to cefoperazone (letter). Ann Intern Med 1985; 102:721-722. PubMed
- Cristiano P: Hypoprothrombinemia associated with cefoperazone treatment. Drug Intell Clin Pharm 1984; 18:314-316. PubMed
Keep reading about Warfarin
Keep reading about Cefotetan Injection
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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