Carprofen
**Carprofen** is a non-steroidal anti-inflammatory drug (NSAID) of the propionic acid class, widely used in veterinary medicine. * **Primary Use:** Management of pain and inflammation associated with osteoarthritis and control of postoperative pain associated with soft tissue and orthopedic surgeries in dogs. * **Clinical Pearl:** While highly effective, it requires careful patient selection to avoid gastrointestinal, renal, or hepatic adverse events. > **Note:** Carprofen is generally considered to be a COX-2 preferential NSAID, meaning it targets the inflammatory pathways while largely sparing the protective homeostatic functions of COX-1.
Mechanism: Carprofen produces its analgesic and anti-inflammatory effects via the inhibition of cyclooxygenase (COX) enzymes. **Arachidonic Acid** โ **Cyclooxygenase (COX)** โ **Prostaglandins & Thromboxanes** * **COX-1 Sparing:** It preferentially inhibits **COX-2** (induced during inflammation) over **COX-1** (constitutively expressed for GI and renal protection). * **Additional Mechanisms:** May also inhibit the release of several prostaglandins and modulate cellular and humoral immune responses.
Dosing by species
- Post-operative pain ยท 4 mg/kg ยท SC/IV ยท Single dose ยท One time only ยท Use with extreme caution in cats due to limited glucuronidation capacity; single dose only. Not approved for multi-day use in cats in many countries.
- Analgesia ยท 1-2 mg/kg ยท PO/SC ยท q12-24h ยท As needed
- Adjunct therapy for acute mastitis or respiratory disease ยท 1.4 mg/kg ยท SC/IV ยท Single dose ยท One time ยท Approved in some regions outside the US.
- Pain and Inflammation ยท 0.7 mg/kg ยท IV ยท q24h ยท As needed ยท Used primarily outside the US.
- Analgesia ยท 1-2 mg/kg ยท PO/IM/SC ยท q12-24h ยท As needed ยท Dosing varies significantly by species.
- Analgesia ยท 2-5 mg/kg ยท PO/SC ยท q12-24h ยท As needed ยท Commonly used in rabbits, guinea pigs, and rodents.
- Osteoarthritis and Pain Management ยท 4.4 mg/kg ยท PO/SC/IV ยท q24h or divided q12h ยท As needed ยท Can be given as a single daily dose or divided into 2.2 mg/kg twice daily.
Routes of administration
Contraindications
- Bleeding disorders (e.g., Von Willebrand disease)
- Active gastrointestinal ulceration
- Hypersensitivity to carprofen or other NSAIDs
- Concurrent use with other NSAIDs or corticosteroids
Adverse effects
- Vomiting
- Diarrhea
- Anorexia
- Lethargy
- Gastrointestinal ulceration or bleeding
- Hepatopathy (rare, idiosyncratic)
- Renal toxicity
Drug interactions
- Corticosteroids ยท Significantly increased risk of gastrointestinal ulceration and perforation. ยท major
- Other NSAIDs ยท Increased risk of GI, renal, and hepatic toxicity. ยท major
- ACE Inhibitors ยท Potential for increased risk of renal toxicity and decreased hypotensive efficacy. ยท moderate
- Phenobarbital ยท Potential for altered metabolism and increased risk of hepatotoxicity.
- Furosemide ยท Decreased diuretic efficacy. ยท moderate
Monitoring
- Baseline blood work (CBC/Chemistry panel)
- Liver enzymes (ALT, AST, ALP, Bilirubin)
- Renal parameters (BUN, Creatinine, SDMA, USG)
- Clinical signs of GI upset (vomiting, diarrhea, melena)
Overdose
**Signs of Toxicity:** * **GI:** Vomiting, diarrhea, hematemesis, melena, GI ulceration/perforation. * **Renal:** Acute kidney injury (AKI), polyuria, polydipsia. * **Hepatic:** Elevated liver enzymes, icterus. * **Neurologic:** Seizures or coma in massive overdoses. **Treatment:** 1. **Decontamination:** Emesis induction (if recent and asymptomatic), followed by activated charcoal. 2. **GI Protectants:** Omeprazole, misoprostol, sucralfate. 3. **Fluid Therapy:** IV crystalloids to support renal perfusion and promote diuresis. 4. **Monitoring:** Serial monitoring of renal and hepatic values for at least 48-72 hours.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturerโs current label.