azithromycin vs warfarin
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Side-by-side comparison of azithromycin and warfarin. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
minor Known Drug Interaction
( 7.1 ) • Warfarin: Use with azithromycin may increase coagulation times; monitor prothrombin time. [see Adverse Reactions (6) ] 7.2 Warfarin Spontaneous postmarketing reports suggest that concomitant administration of azithromycin may potentiate the effects of oral anticoagulants such as warfarin, although the prothrombin time was not affected in the dedicated drug interaction study with azithromycin and warfarin.
Zithromax, Z-Pack
Coumadin, Jantoven
Azithromycin is an antibiotic that fights bacteria. It is used to treat many different types of infections.
Warfarin is a medicine that helps prevent blood clots. It is used to treat and prevent dangerous clots from forming in your body.
Azithromycin treats mild to moderate infections caused by certain bacteria. In adults, it can treat bronchitis, sinus infections, skin infections, urethritis, cervicitis, and genital ulcers. In children over 6 months old, it can treat ear infections and pneumonia. It can also treat pharyngitis/tonsillitis in children 2 years and older.
Warfarin is used to prevent and treat blood clots in your veins and lungs. It can also prevent clots if you have atrial fibrillation (irregular heartbeat) or a replacement heart valve. After a heart attack, it can lower the risk of death, another heart attack, or a stroke.
Azithromycin belongs to a class of drugs called macrolide antibiotics. It works by stopping the growth of bacteria. This helps your body fight off the infection.
Warfarin works by blocking your body's use of vitamin K. Vitamin K is needed to make blood clotting factors. By blocking vitamin K, warfarin makes your blood less likely to clot.
- • Diarrhea (5-14%)
- • Nausea (3-18%)
- • Abdominal pain (3-7%)
- • Vomiting (2-7%)
- • Bleeding from any tissue or organ
- Dyspnoea 3,059
- Nausea 2,232
- Pain 2,205
- Pneumonia 2,085
- Cough 2,031
- International Normalised Ratio Increased 10,276
- Dyspnoea 8,408
- Drug Interaction 6,288
- Fatigue 6,143
- Nausea 5,921
This drug can cause serious allergic reactions, liver problems, and heart rhythm changes. Tell your doctor right away if you have signs of an allergic reaction, like rash or swelling. Also, tell your doctor if you have liver problems, heart problems, or muscle weakness.
Warfarin can cause major or fatal bleeding. You must have your blood tested regularly (INR) while taking warfarin. Many things, like other medicines and diet changes, can affect your INR. Tell your doctor about any bleeding and follow their instructions to prevent bleeding.
Studies haven't shown major risks to the baby during pregnancy. Talk to your doctor if you are pregnant or breastfeeding before taking this medicine.
Warfarin can harm your unborn baby, especially during the first three months of pregnancy. Do not take warfarin if you are pregnant, unless you have a mechanical heart valve and your doctor says the benefits outweigh the risks. Talk to your doctor if you are breastfeeding, and watch your baby for bruising or bleeding.
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How to Read This azithromycin vs warfarin Comparison
azithromycin is classified in the Macrolide Antibiotic drug class, while warfarin sits within the Vitamin K Antagonist (Anticoagulant) class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are prescription-only, so a licensed provider must authorize use.
Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, azithromycin has 11,612 submissions while warfarin has 37,036. Those figures reflect cumulative reporting volume, not per-patient risk, so older, widely dispensed drugs typically look worse on count alone. These two drugs have a known minor interaction flagged in FDA labeling, attributed to azithromycin may increase the effects of warfarin, which can make your blood take longer to clot.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.
A table cannot represent individual circumstances. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This registry does not provide medical, treatment, substitution, or medication-change directions for azithromycin or warfarin.
Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.