diclofenac vs mefenamic acid
Side-by-side comparison of diclofenac 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.
minor Known Drug Interaction
NSAIDs with short elimination half-lives (e.g., diclofenac, indomethacin) should be avoided for a period of two days before, the day of, and two days following administration of pemetrexed.
Recommendation: You should avoid taking these two medications at the same time.
Voltaren, Cataflam
Ponstel
Diclofenac is a gel that helps with arthritis pain in your hands, wrists, elbows, feet, ankles, or knees. 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).
This medicine temporarily relieves arthritis pain. It is only for pain in your hands, wrists, elbows, feet, ankles, or knees. It may take up to 7 days to start working. If you still have pain after 7 days, stop using it.
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.
Diclofenac is an NSAID. It reduces pain and swelling by blocking substances in the body that cause inflammation.
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.
- • Pain
- • Headache
- • Abdominal pain
- • Constipation
- • Diarrhea
- • Upset stomach
- • Gas
- Medicine not working 13,689
- Pain 12,281
- Tiredness 11,317
- Rheumatoid arthritis 9,240
- Rash 8,747
- The medicine did not work 352
- Feeling sick to your stomach 296
- Feeling tired 253
- Head pain 227
- General pain 202
There are no boxed warnings in the provided data.
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.
There is no information about pregnancy or breastfeeding in the provided data.
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.
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How to Read This diclofenac vs mefenamic acid Comparison
diclofenac 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 split between OTC and prescription status, which affects access and supervision.
Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, diclofenac has 55,274 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 minor interaction flagged in FDA labeling, attributed to taking two different nsaid pain relievers together increases the risk of serious side effects like stomach bleeding and kidney problems.. 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 diclofenac 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.