Difene is Diclofenac Sodium
Difene is a trade name for diclofenac sodium, a nonsteroidal anti-inflammatory drug (NSAID) used to treat pain and inflammation, particularly in conditions like osteoarthritis. 1
Drug Classification and Mechanism
Diclofenac sodium belongs to the phenylacetic acid class of NSAIDs and works primarily through:
- COX-2 selective inhibition: Unlike many traditional NSAIDs, diclofenac inhibits cyclooxygenase-2 (COX-2) with greater potency than COX-1 1
- Anti-inflammatory, analgesic, and antipyretic properties through prostaglandin synthesis inhibition 2
- Multiple additional mechanisms including effects on arachidonic acid pathways, lipoxygenase inhibition, and nitric oxide-cGMP pathway activation 2
Available Formulations
Difene and other diclofenac products come in various formulations 1:
- Enteric-coated tablets (25 mg, 50 mg, 75 mg) - delayed release to reduce GI effects 3
- Immediate-release tablets (diclofenac potassium) - faster absorption for rapid pain relief 1
- Extended-release formulations - once-daily dosing 1
- Topical solutions (1.5%, 2%) - for localized treatment with reduced systemic absorption 4, 5
Critical Safety Warnings
Diclofenac carries FDA black box warnings for serious cardiovascular and gastrointestinal risks 3:
Cardiovascular Risk
- Significantly increased risk of MI, stroke, and cardiovascular death
- Registry data shows mortality RR of 2.40 (2.09-2.80) - the highest among commonly used NSAIDs 3
- Recurrent MI risk RR 1.54 (1.23-1.93) 3
- Contraindicated for perioperative pain in CABG surgery 3
Gastrointestinal Risk
- Increased risk of bleeding, ulceration, and perforation
- Can occur at any time without warning symptoms
- Elderly patients at greater risk 3
Clinical Positioning
For osteoarthritis pain management, evidence-based guidelines recommend 6:
- First-line: Paracetamol (most cost-effective)
- Second-line: Ibuprofen (if paracetamol inadequate)
- Consider diclofenac only after other options, given its higher cardiovascular risk profile
The cardiovascular risk profile of diclofenac is comparable to selective COX-2 inhibitors and significantly worse than naproxen or ibuprofen 3. This makes it a less favorable choice for patients with cardiovascular disease or risk factors.
Key Clinical Caveat
While diclofenac demonstrates efficacy for pain relief (NNT 2.3 for 50 mg dose) 7, its elevated cardiovascular mortality risk (RR 2.40) should make clinicians strongly consider alternative NSAIDs like naproxen (mortality RR not significantly elevated) or ibuprofen (mortality RR 1.50) for most patients 3.