Piroxicam
Oxicam derivative
Also known as: Feldene · Brexidol · CP-16171 · piroxicamum
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 |
|---|---|---|---|---|---|
| Adjunctive therapy of transitional cell carcinomas, squamous cell carcinomas, and palliative therapy for other neoplastic diseases | 0.3 mg/kg PO once a day | PO | q24h | — | 🌎 NA |
| Adjunctive therapy of neoplastic diseases (for dogs who tolerate NSAIDs poorly) | 0.3 mg/kg PO once a day. Give with food. Consider adding misoprostol at 3 micrograms/kg, PO q8h | PO | q24h | — | 🌎 NA |
| Adjuvant therapy for splenic hemangiosarcoma (stage II) | 0.3 mg/kg PO every day | PO | q24h | Until disease recurrence/progression | 🌎 NA |
| Transitional cell carcinoma after laser ablation of the primary tumor | 0.3 mg/kg PO once daily | PO | q24h | Remaining life of the dog | 🌎 NA |
| Inhibit local recurrence in dogs with incompletely resected soft tissue sarcomas | 0.3 mg/kg PO once daily | PO | q24h | — | 🌎 NA |
| Antiinflammatory/analgesic | 0.3 mg/kg PO every other day (q48h) | PO | q48h | — | 🌎 NA |
| Cancer pain | 0.3 mg/kg PO q24-48h | PO | q24-48h | — | 🌎 NA |
| Adjunctive treatment of Idiopathic lymphoplasmacytic rhinitis (LPR) | 0.3 mg/kg PO q24h | PO | q24h | Minimum of 6 months, if not indefinitely | 🌎 NA |
| All uses (e.g., transitional cell carcinoma, prostatic carcinoma) | 0.3 mg/kg | PO | q24-72h | Long-term | 🌍 EU |
| Colorectal polyps/neoplasia | 20 mg/dog | PR | q2-3days | Long-term | 🌍 EU |
- Adjunctive therapy of neoplastic diseases (for dogs who tolerate NSAIDs poorly): Discontinue if severe irritation or ulceration occurs.
- Adjuvant therapy for splenic hemangiosarcoma (stage II): Given with Etoposide and Cyclophosphamide protocols.
- Transitional cell carcinoma after laser ablation of the primary tumor: Given with Mitoxantrone.
- Inhibit local recurrence in dogs with incompletely resected soft tissue sarcomas: Given with cyclophosphamide at 10 mg/m2 PO once daily. Decrease to every other day if unacceptable adverse effects develop.
- Adjunctive treatment of Idiopathic lymphoplasmacytic rhinitis (LPR): Combined with doxycycline or azithromycin.
- All uses (e.g., transitional cell carcinoma, prostatic carcinoma): Start at least frequent administration and slowly increase if no side effects observed.
- Colorectal polyps/neoplasia: Dose equivalent to 0.24-0.4 mg/kg/day. Uses human suppositories.
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Adjunctive therapy of transitional cell carcinomas | 0.3 mg/kg PO q24-72h | PO | q24-72h | — | 🌎 NA |
| Adjunctive therapy of transitional cell carcinomas/neoplastic diseases | 0.3 mg/kg PO every 24-48 hours | PO | q24-48h | — | 🌎 NA |
| Cancer pain | 0.3 mg/kg PO q24-48h or 1 mg (total dose) per cat PO q24h | PO | q24-48h | Maximum of 7 days | 🌎 NA |
| Antiinflammatory/analgesic | 1 mg per cat (total dose) PO once daily | PO | q24h | Maximum of 7 days | 🌎 NA |
| Idiopathic chronic rhinosinusitis | 0.3 mg/kg PO once daily or every other day | PO | q24-48h | — | 🌎 NA |
| All uses (e.g., various neoplasms) | 0.3 mg/kg | PO | q24-96h | Long-term | 🌍 EU |
- Adjunctive therapy of transitional cell carcinomas: Gastric protectants may be useful. Use with caution in pre-existing renal disease.
- All uses (e.g., various neoplasms): Start at least frequent administration and slowly increase if no side effects observed.
Small Mammals
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Fracture associated limb swelling (Rabbits) | 0.1-0.2 mg/kg PO q8h | PO | q8h | 3 weeks | 🌎 NA |
Horses
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Mucocutaneous squamous cell carcinoma | 80 mg (total dose) PO once daily | PO | q24h | — | 🌎 NA |
| Squamous cell carcinoma of the third eyelid after surgical excision | 80 mg (total dose) PO once daily | PO | q24h | — | 🌎 NA |
- Mucocutaneous squamous cell carcinoma: Dose was eventually reduced to every other day or every third day due to colic signs.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Piroxicam is a non-steroidal anti-inflammatory drug (NSAID) of the oxicam class. While it possesses standard NSAID properties (anti-inflammatory, analgesic, and antipyretic), its primary use in veterinary medicine is as an adjunctive treatment for transitional cell carcinoma (TCC) of the bladder in dogs, as well as other neoplasms like squamous cell carcinomas and mammary adenocarcinomas.
Clinical Pearl: Piroxicam has a very narrow therapeutic index in dogs and cats compared to newer, COX-2 selective NSAIDs. It is rarely used solely for osteoarthritis pain today due to the high risk of gastrointestinal ulceration.
It is increasingly used in metronomic (low-dose, continuous) chemotherapy protocols alongside drugs like cyclophosphamide to prevent sarcoma recurrence by inhibiting angiogenesis and modulating the immune system.
Mechanism of action
Like other NSAIDs, piroxicam non-selectively inhibits cyclooxygenase (COX) enzymes, thereby blocking the conversion of arachidonic acid to prostaglandins and thromboxanes. This reduces inflammation and pain.
Its anti-tumor effects are not fully understood but are believed to be indirect. Mechanisms include:
- Inhibition of COX-2 expressed by tumor cells (especially TCC)
- Anti-angiogenesis (preventing new blood vessel formation to the tumor)
- Immune system modulation
- Inhibition of superoxide formation
Safety & warnings
Contraindications
- Hypersensitivity to piroxicam, aspirin, or other NSAIDs
- Active or history of gastrointestinal ulcer disease
- Bleeding disorders
- Gastric ulceration
- Renal disease
- Concurrent use of corticosteroids
- Concurrent use of other NSAIDs
- Dehydration (relative contraindication due to renal risk)
Adverse effects
- Gastrointestinal ulceration and bleeding (melena, hematemesis)
- Vomiting, anorexia, and diarrhea
- Renal papillary necrosis
- Peritonitis (secondary to GI perforation)
- Decreased hematocrit (anecdotal in cats)
- Peripheral edema
- Elevated liver enzymes
- Gastrointestinal toxicity
- Gastric ulceration
- Ulcerative skin lesions (reported in cats)
- Potential precipitation of cardiac failure (known in humans, unknown risk in animals)
Precautions
Extreme Caution: Use in cats is controversial and must be done with extreme caution due to lack of safety studies and potential for severe GI/renal toxicity. Caution: Use carefully in patients with severely compromised cardiac function due to potential for peripheral edema. The therapeutic window in dogs is very narrow; doses as low as 1 mg/kg daily have caused severe GI ulceration and peritonitis.
Drug interactions
Increased risk for nephrotoxicity
Increased risk for bleeding
Decreased piroxicam plasma levels and increased likelihood of GI adverse effects (blood loss); do not use concurrently
May increase risk for GI ulceration
May potentiate the renal toxicity of cisplatin
Significantly increased risk for GI adverse effects and ulceration
May reduce the saluretic and diuretic effects of furosemide
Piroxicam is 99% protein-bound and may displace other drugs, increasing their serum levels and duration of action
Serious toxicity has occurred when used concomitantly; use with extreme caution
Increased risk of severe gastric ulceration and GI toxicity
Increased risk of nephrotoxicity and renal papillary necrosis
Increased risk of nephrotoxicity
Piroxicam is highly protein-bound and may displace other drugs, potentially increasing their free plasma concentrations
Monitoring
- Adverse Effects (particularly GI bleeding: melena, hematemesis, pale mucous membranes)
- Liver function tests (occasionally with chronic use)
- Renal function tests (occasionally with chronic use)
- Renal function (BUN, Creatinine, SDMA, Urinalysis)
- Liver enzymes
- Clinical signs of GI ulceration (vomiting, melena, anorexia)
- Hydration status
- Skin integrity (especially in cats)
Pharmacokinetics
Half-life
Absorption
Well absorbed from the gut. Food decreases the rate of absorption but not the total amount absorbed. Oral bioavailability is 100% in dogs and ~80% in cats. Peak plasma levels occur around 3 hours post-dosing.
Distribution
Volume of distribution is ~0.3 L/kg in dogs. Highly bound to plasma proteins (99%). Synovial levels are ~40% of plasma levels. Maternal milk concentrations are ~1% of plasma levels.
Metabolism
Undergoes hepatic biotransformation.
Elimination
Principally excreted as metabolites in the urine. Total body clearance in dogs is 0.066 L/hour.
Overdose
Overdosage can lead to severe gastrointestinal (ulceration, perforation) and renal (papillary necrosis, failure) effects. Dogs may be more sensitive to the ulcerative effects than humans.
Treatment:
- Decontamination with emetics and/or activated charcoal if recent.
- Gastrointestinal protectants (e.g., misoprostol, omeprazole, sucralfate) are strongly warranted.
- Fluid diuresis should be considered to protect renal function.
- Monitor carefully and provide supportive care.
Available products
Formulations
- Oral capsules
- 10 mg capsule
- 20 mg capsule
- 20 mg dissolving tablet
- 20 mg/ml injectable solution
- 20 mg suppository
Human-labeled
- Piroxicam Oral Capsules: 10 mg & 20 mg; Feldene® (Pfizer); generic
- Brexidol
- Generic Piroxicam capsules, dissolving tablets, suppositories, and injectable solutions
Regulatory status
POM. Human authorized products used off-label under the cascade.
POM. Human authorized products used off-label under the cascade.
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Capsules should be stored at temperatures less than 30°C (86°F) in tight, light-resistant containers. Expiration is typically 36 months after manufacture when stored properly.
Client information
Piroxicam is a strong anti-inflammatory medication often used to help treat certain types of cancer in pets.
- Give with food: This can help reduce the chance of stomach upset.
- Watch for stomach ulcers: Stop the medication and contact your veterinarian immediately if your pet stops eating, vomits (especially if it looks like coffee grounds or has blood), or has dark, tarry stools.
- Do not mix medications: Never give your pet aspirin, other NSAIDs (like Rimadyl, Metacam), or steroids (like prednisone) while they are taking piroxicam unless explicitly directed by your veterinarian.
- Strict dosing: Do not exceed the prescribed dose, as the safety margin for this drug is very narrow in pets.
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.