Duloxetine vs Diclofenac: side-by-side comparison
Duloxetine (Serotonin-norepinephrine reuptake inhibitor (SNRI)) 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 | Duloxetine | Diclofenac |
|---|---|---|
| Therapeutic class | Serotonin-norepinephrine reuptake inhibitor (SNRI) | NSAID (phenylacetic acid) |
| CAS | 116539-59-4 | 15307-86-5 |
| ATC | N06AX21 | M01AB05 |
| Molecular weight | 297.41 g/mol | 296.15 g/mol |
| Brands with this active ingredient | 1 | 1 |
What they share
Duloxetine 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
Duloxetine 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
Duloxetine: Duloxetine inhibits the reuptake of both serotonin and norepinephrine at the synapse, with weaker effect on dopamine. Diclofenac: Diclofenac reversibly inhibits cyclooxygenase enzymes COX-1 and COX-2, with somewhat greater selectivity for COX-2 than ibuprofen and naproxen.
Indications compared
Duloxetine: Duloxetine is approved for major depressive disorder, generalised anxiety disorder, diabetic peripheral neuropathic pain, fibromyalgia, chronic musculoskeletal pain (back pain, osteoarthritis) and stress urinary incontin… 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
Duloxetine: Common adverse effects include nausea (most prominent in the first 1–2 weeks), dry mouth, headache, fatigue, sleep disturbance and sexual dysfunction. Diclofenac: Common adverse effects include gastrointestinal symptoms, headache, dizziness and elevated liver enzymes.
Frequently asked questions
Is Duloxetine better than Diclofenac? ▾
Duloxetine and Diclofenac are not "better or worse" — they treat different things. The sensible question is which fits your specific need.
Can Duloxetine 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 Duloxetine
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.