diflunisal vs mefenamic acid
Side-by-side comparison of diflunisal and mefenamic acid 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
NSAIDs and Salicylates Clinical Impact: Concomitant use of mefenamic acid with other NSAIDs or salicylates (e.g., diflunisal, salsalate) increases the risk of GI toxicity, with little or no increase in efficacy (see Warnings ; Gastrointestinal Bleeding, Ulceration and Perforation ).
Recommendation: Avoid taking these two medications at the same time. Your doctor should help you choose just one of these drugs to manage your symptoms safely.
Dolobid
Ponstel
Diflunisal is a medicine that can help with pain and swelling. It belongs to a class of drugs called NSAIDs.
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).
Diflunisal can help with mild to moderate pain. It can also treat the symptoms of osteoarthritis and rheumatoid arthritis. You should use the lowest dose that works for you, for the shortest time needed.
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.
Diflunisal reduces pain and swelling by blocking the production of certain chemicals in your body. These chemicals cause inflammation and pain. By blocking them, diflunisal helps to relieve your symptoms.
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.
- • Nausea
- • Vomiting
- • Upset stomach
- • Stomach pain
- • Diarrhea
- • Abdominal pain
- • Constipation
- • Diarrhea
- • Upset stomach
- • Gas
- Feeling sick to your stomach 66
- Feeling very tired 57
- Discomfort or aching 50
- Allergic reaction to the medicine 47
- Pain in your head 45
- The medicine did not work 352
- Feeling sick to your stomach 296
- Feeling tired 253
- Head pain 227
- General pain 202
NSAIDs like diflunisal can increase your risk of heart problems like heart attack and stroke, which can be deadly. This risk is higher if you take it for a long time. You should not take diflunisal if you are having heart bypass surgery. NSAIDs also raise your risk of serious stomach problems like bleeding and ulcers, which can also be deadly. Older adults are at higher risk for these stomach problems.
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.
Tell your doctor if you are pregnant or plan to become pregnant. Taking diflunisal late in pregnancy may harm your baby. It is not known if diflunisal passes into breast milk, so talk to your doctor before breastfeeding.
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.
Also Compare — Nearby Drugs
Compare diflunisal with
Compare mefenamic acid with
How to Read This diflunisal vs mefenamic acid Comparison
diflunisal is classified in the Nonsteroidal Anti-Inflammatory Drug (NSAID) drug class, while mefenamic acid sits within the Nonsteroidal Anti-Inflammatory Drug (NSAID) class. Because both drugs share the same classification, they are often considered interchangeable in theory — but clinical outcomes rarely track that cleanly. 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, diflunisal has 265 submissions while mefenamic acid has 1,330. 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 taking these two drugs together increases the risk of stomach bleeding and ulcers without providing extra relief. both drugs are similar and can irritate the lining of your digestive system.. 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 diflunisal and mefenamic acid — 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.