Fexofenadine vs Diclofenac: side-by-side comparison
Fexofenadine (Second-generation H1 antihistamine) and Diclofenac (NSAID (phenylacetic acid)) belong to different therapeutic classes and are rarely substitutes for each other. The comparison is useful when a single patient is weighing both options for adjacent or overlapping needs.
| Property | Fexofenadine | Diclofenac |
|---|---|---|
| Therapeutic class | Second-generation H1 antihistamine | NSAID (phenylacetic acid) |
| CAS | 83799-24-0 | 15307-86-5 |
| ATC | R06AX26 | M01AB05 |
| Molecular weight | 501.66 g/mol | 296.15 g/mol |
| Brands with this active ingredient | 1 | 1 |
What they share
Fexofenadine and Diclofenac share the common regulatory framework for prescription active ingredients, bioequivalence standards for generics, and pharmacist oversight. Beyond that, points in common are limited.
Key differences
Fexofenadine acts by a different mechanism than Diclofenac, with indications that barely overlap. Comparing the two is useful when a clinician has mentioned both in the same context or the patient wants to understand why one was prescribed instead of the other.
Mechanisms compared
Fexofenadine: Fexofenadine selectively blocks peripheral H1 histamine receptors, antagonising the effects of histamine on vasodilation, capillary permeability, sensory nerve endings and smooth muscle. Diclofenac: Diclofenac reversibly inhibits cyclooxygenase enzymes COX-1 and COX-2, with somewhat greater selectivity for COX-2 than ibuprofen and naproxen.
Indications compared
Fexofenadine: Fexofenadine is approved in adults and children for the treatment of seasonal allergic rhinitis and chronic idiopathic urticaria. Diclofenac: Diclofenac is approved in adults for the treatment of osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, acute musculoskeletal pain, post-surgical pain, primary dysmenorrhoea, acute migraine and ureteric colic…
Safety profile
Fexofenadine: Fexofenadine is very well tolerated. Diclofenac: Common adverse effects include gastrointestinal symptoms, headache, dizziness and elevated liver enzymes.
Frequently asked questions
Is Fexofenadine better than Diclofenac? ▾
Fexofenadine and Diclofenac are not "better or worse" — they treat different things. The sensible question is which fits your specific need.
Can Fexofenadine and Diclofenac be combined? ▾
Whether they can be combined depends on the indications and the interaction profile of each. If both are in a single prescription, the prescriber has weighed it; in self-medication they should never be combined.
Do they have the same side-effect profile? ▾
No — they belong to different classes and have distinct side-effect profiles. Each has its own prescribing information.
Products with Fexofenadine
Products with Diclofenac
The information on this website is provided for reference and educational purposes only. It does not replace consultation with a qualified healthcare professional.