What the FDA labels say about taking them together
Diclofenac and mefenamic acid
Mefenamic acid's FDA label of April 20, 2026 names diclofenac in its drug interactions section; diclofenac's label does not name mefenamic acid itself but warns about its class (NSAIDs (nonsteroidal anti-inflammatory drugs)).
Check it at the source: the diclofenac FDA label on DailyMed (effective February 11, 2025, Haleon US Holdings LLC); the mefenamic acid FDA label on DailyMed (effective April 20, 2026, Lupin Pharmaceuticals, Inc.).
What does the diclofenac label say about mefenamic acid?
Diclofenac's label does not name mefenamic acid itself; it warns about its class (NSAIDs (nonsteroidal anti-inflammatory drugs)):
Diclofenac label, boxed warningThis risk may occur early in the treatment and may increase with duration of use ( 5.1 ) LICART is contraindicated in the setting of coronary artery bypass graft (CABG) surgery. ( 4 , 5.1 ) NSAIDs cause an increased risk of serious gastrointestinal (GI) adverse events including bleeding, ulceration, and perforation of the stomach or intestines, which can be fatal.
Diclofenac label, boxed warningGastrointestinal Bleeding, Ulceration, and Perforation NSAIDs cause an increased risk of serious gastrointestinal (GI) adverse events including bleeding, ulceration, and perforation of the stomach or intestines, which can be fatal.
Source: FDA drug label (Voltaren Arthritis Pain), Haleon US Holdings LLC, effective February 11, 2025 (SPL set 30a94282-0892-442a-aa10-6525cbd4fe88), via openFDA; the full label on DailyMed
What does the mefenamic acid label say about diclofenac?
Mefenamic acid label, drug interactionsNSAIDs 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.
Source: FDA drug label (Mefenamic Acid), Lupin Pharmaceuticals, Inc., effective April 20, 2026 (SPL set d15733a9-d5fd-4d5f-86ce-e7ed8c706c7f), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Diclofenac | Mefenamic acid | |
|---|---|---|
| Labeled for | Pain, Osteoarthritis, Rheumatoid arthritis, Migraine | Pain |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.0619 per tablet 75 mg tablet | $0.948 per capsule 250 mg capsule |
| Shortage now | A presentation being discontinued | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once