Diclofenac Sodium
Phenyl-acetic acid derivative
Also known as: Surpass · Cataflam · Voltaren-XR · Solaraze · Arthrotec · Voltarol Ophtha Multidose · GP-45840 · diclofenacum · diclophenac · Diclofenac sodium
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Ocular inflammation / Uveitis | 1 drop per affected eye | topical | bid to qid | As directed by veterinarian | 🌍 EU |
- Ocular inflammation / Uveitis: Standard veterinary ophthalmic dosing; not explicitly stated in the provided monograph.
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Ocular inflammation / Uveitis | 1 drop per affected eye | topical | bid to qid | As directed by veterinarian | 🌍 EU |
- Ocular inflammation / Uveitis: Standard veterinary ophthalmic dosing; not explicitly stated in the provided monograph.
Horses
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Control of pain and inflammation associated with osteoarthritis in tarsal, carpal, metacarpophalangeal, metarsophalangeal, and proximal interphalangeal (hock, knee, fetlock, pastern) joints | Apply a five inch ribbon | topical | twice daily | up to 10 days | 🌎 NA |
- Control of pain and inflammation associated with osteoarthritis in tarsal, carpal, metacarpophalangeal, metarsophalangeal, and proximal interphalangeal (hock, knee, fetlock, pastern) joints: Wear rubber gloves and rub cream thoroughly into the hair covering the joint until cream disappears.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Diclofenac sodium is a non-steroidal antiinflammatory drug (NSAID).
- Veterinary Use: FDA-approved as a topical liposomal cream (Surpass®) for horses to control local joint pain and inflammation associated with osteoarthritis.
- Systemic Use: While theoretically usable systemically in other species, safer FDA-approved alternatives exist for dogs and cats.
Important Toxicity Note: Diclofenac is highly toxic to birds (especially vultures), causing fatal renal failure. It should never be used in avian species.
Mechanism of action
Diclofenac is a non-specific inhibitor of cyclooxygenase (COX-1 and COX-2) enzymes.
- Arachidonic Acid Cascade: Inhibits the conversion of arachidonic acid → prostaglandins and thromboxanes.
- Lipooxygenase: May also have some inhibitory effects on the lipooxygenase pathway, reducing leukotriene production.
- Result: Decreased production of inflammatory mediators leads to reduced pain, hyperpyrexia, and inflammation.
Safety & warnings
Contraindications
- Hypersensitivity to diclofenac or any component of the cream
- Horses less than one year old
- Birds (implicated in causing death in vultures)
Adverse effects
- Colic (horses)
- Weight loss
- Gastric ulcers
- Uterine discharge
- Local inflammation
- Swelling
- Alopecia
- Vomiting (dogs/cats)
- Bloody diarrhea/melena (dogs/cats)
- Polydipsia (dogs/cats)
Precautions
Exceeding the recommended dosage or treating multiple joints may cause adverse effects. Reproductive safety for topical diclofenac has not been investigated in breeding, pregnant, or lactating horses. Do not use in birds.
Drug interactions
Increased risk of delayed corneal healing and severe corneal complications (corneal melting) when used concurrently.
NSAIDs may theoretically blunt the intraocular pressure-lowering effect of prostaglandin analogues.
Monitoring
- Efficacy (reduction in pain/inflammation)
- Adverse effects (GI signs, local skin reactions)
Pharmacokinetics
Absorption
Absorbed locally when applied topically to horses via 1% liposomal cream. Peak levels in transudate ~80 ng/mL; levels stay increased from 6 to at least 18 hours.
Distribution
Most drug remains in local tissues near administration point, but detectable systemic levels may occur. >99% bound to plasma proteins in humans.
Metabolism
Metabolized in the liver.
Elimination
Metabolites are excreted primarily into the urine.
Overdose
As an NSAID, overdosage primarily affects the gastrointestinal and renal systems.
- Horses (Topical Overdose): Weight loss, gastric ulcers, colic, diarrhea, and uterine discharge.
- Dogs/Cats (Ingestion): Vomiting, diarrhea (often bloody/melena), and polydipsia.
- Treatment:
- Decontamination: Emetics and/or activated charcoal for recent ingestions.
- GI Protection: Use of gastrointestinal protectants (e.g., sucralfate, omeprazole) is warranted if GI effects are expected.
- Renal Protection: Fluid diuresis is warranted if renal effects are anticipated.
- Supportive Care: Symptomatic treatment as needed.
Available products
Formulations
- 1% topical liposomal cream
- Delayed-release tablets
- 3% topical gel
- Tablets with misoprostol
- Topical ophthalmic drops
Veterinary
- Diclofenac sodium (liposomal) 1% topical cream in 124 g tubes (Surpass)
Human-labeled
- Diclofenac Tablets: 50 mg (Cataflam)
- Diclofenac Delayed-release Tablets: 25 mg, 50 mg, 75 mg & 100 mg (Voltaren-XR)
- Diclofenac Sodium Gel: 3% (Solaraze)
- Diclofenac Sodium/Misoprostol Tablets: 50 mg/200 mcg & 75 mg/200 mcg (Arthrotec)
Regulatory status
Human-approved ophthalmic products used off-label under the cascade.
Human-approved ophthalmic products (POM) used off-label under the cascade.
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store in airtight containers and protect from light. The commercially available 1% cream (Surpass) should be stored at temperatures up to 25°C (77°F); protect from freezing.
Client information
- Strict Adherence: Use exactly as directed. Do not increase the dose (area applied) or duration (do not exceed 10 days) to prevent adverse effects.
- Safety Precautions: Always wear non-permeable protective gloves when applying the cream to avoid absorbing the medication yourself.
- Monitoring: Watch for signs of gastrointestinal upset (e.g., loss of appetite, diarrhea, or colic in horses) and contact your veterinarian if they occur.
- Information Sheet: Read the client information sheet supplied with the medication.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.