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mefenamic acid vs warfarin

Side-by-side comparison of mefenamic acid and warfarin. Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.

moderate Known Drug Interaction

Table 3: Drugs that Can Increase the Risk of Bleeding Drug Class Specific Drugs Anticoagulants argatroban, dabigatran, bivalirudin, desirudin, heparin, lepirudin Antiplatelet Agents aspirin, cilostazol, clopidogrel, dipyridamole, prasugrel, ticlopidine Non-steroidal Anti-Inflammatory Agents celecoxib, diclofenac, diflunisal, fenoprofen, ibuprofen, indomethacin, ketoprofen, ketorolac, mefenamic acid, naproxen, oxaprozin, piroxicam, sulindac Serotonin Reuptake Inhibitors citalopram, desvenlafaxine, duloxetine, escitalopram, fluoxetine, fluvoxamine, milnacipran, paroxetine, sertraline,...

Recommendation: Use this combination with caution and under a doctor's supervision. Your healthcare provider may need to change your medication plan.

Drug Class
mefenamic acid Nonsteroidal Anti-Inflammatory Drug (NSAID)
warfarin Vitamin K Antagonist (Anticoagulant)
Type
mefenamic acid Prescription
warfarin Prescription
Summary
mefenamic acid

Mefenamic acid is a medicine used to treat mild to moderate pain and menstrual cramps. It is a type of nonsteroidal anti-inflammatory drug (NSAID).

warfarin

Warfarin is a medicine that helps prevent blood clots. It is used to treat and prevent dangerous clots from forming in your body.

What It Treats
mefenamic acid

Mefenamic acid is used to relieve mild to moderate pain in people 14 years and older. It should not be used for more than 7 days. It is also used to treat menstrual cramps.

warfarin

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.

How It Works
mefenamic acid

Mefenamic acid reduces pain and inflammation in the body. It does this by blocking substances in the body that cause pain and swelling. This medicine helps to reduce pain and discomfort.

warfarin

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.

Common Side Effects
mefenamic acid
  • Abdominal pain
  • Constipation
  • Diarrhea
  • Upset stomach
  • Gas
warfarin
  • Bleeding from any tissue or organ
FAERS Reports
mefenamic acid
  • Feeling sick to your stomach 296
  • Feeling tired 253
  • Head pain 227
  • General pain 202
  • Feeling lightheaded 177
warfarin
  • INR increased 10,275
  • Shortness of breath 8,408
  • Interaction with another medicine 6,289
  • Tiredness 6,141
  • Feeling sick to your stomach 5,921
Serious Warnings
mefenamic acid

Mefenamic acid may increase the risk of serious heart problems, including heart attack and stroke, which can be fatal. This risk may occur early in treatment and may increase with longer use. You should not take this medicine if you are having heart bypass surgery. Mefenamic acid can also increase the risk of serious stomach and intestinal problems, including bleeding, ulcers, and holes, which can be fatal. These problems can occur without warning. The elderly and those with a history of stomach ulcers or bleeding are at higher risk.

warfarin

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.

Pregnancy
mefenamic acid

Tell your doctor if you are pregnant or plan to become pregnant. Mefenamic acid may harm your unborn baby. It is not known if mefenamic acid passes into breast milk. Talk to your doctor before breastfeeding.

warfarin

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.

Also Compare, Nearby Drugs

How to Read This mefenamic acid vs warfarin Comparison

mefenamic acid is classified in the Nonsteroidal Anti-Inflammatory Drug (NSAID) 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, mefenamic acid has 1,155 submissions while warfarin has 37,034. 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 moderate interaction flagged in FDA labeling, attributed to mefenamic acid can increase the risk of bleeding when used with warfarin. these drugs work together to slow down blood clotting more than usual.. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.

A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between mefenamic acid and warfarin - always consult your physician or pharmacist first.

Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.