atovaquone/proguanil vs warfarin
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Side-by-side comparison of atovaquone/proguanil 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 ) • Proguanil may potentiate anticoagulant effect of warfarin and other coumarin-based anticoagulants. 7.2 Anticoagulants Proguanil may potentiate the anticoagulant effect of warfarin and other coumarin-based anticoagulants.
Malarone
Coumadin, Jantoven
Malarone is a drug used to prevent and treat malaria. It contains two medicines, atovaquone and proguanil, that work together to kill the malaria parasite.
Warfarin is a medicine that helps prevent blood clots. It is used to treat and prevent dangerous clots from forming in your body.
Malarone is used to prevent malaria, especially in areas where the malaria parasite is resistant to chloroquine. It is also used to treat malaria infections that are not severe. Malarone can be effective even when other malaria drugs don't work well.
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.
Malarone contains two active ingredients: atovaquone and proguanil. Atovaquone stops the malaria parasite's energy production. Proguanil disrupts the parasite's ability to multiply. Together, they kill the parasite and treat or prevent malaria.
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.
- • Abdominal pain
- • Headache
- • Cough
- • Vomiting
- • Diarrhea
- • Bleeding from any tissue or organ
- Fever 429
- Diarrhea 408
- Feeling sick to your stomach 370
- Lung infection 355
- Death 294
- International Normalised Ratio Increased 10,276
- Dyspnoea 8,408
- Drug Interaction 6,288
- Fatigue 6,143
- Nausea 5,921
Elevated liver tests, hepatitis, and liver failure have been reported with Malarone. If you have severe kidney problems, do not use Malarone to prevent malaria. Malarone has not been tested for treating severe malaria affecting the brain, lungs, or kidneys.
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.
It is not known if Malarone can harm an unborn baby. Pregnant women should continue taking folate supplements. Talk to your doctor if you are pregnant or plan to become pregnant 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.
How to Read This atovaquone/proguanil vs warfarin Comparison
atovaquone/proguanil is classified in the Antimalarial Combination 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, atovaquone/proguanil has 1,856 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 proguanil can increase the blood-thinning effects of warfarin, which may make you bleed more easily.. 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 atovaquone/proguanil or warfarin.
Registry boundary: This comparison displays source-record fields and does not provide individualized medical direction.