indication

For use as a pain reliever in the treatment of joint pain and post-surgical pain.

pharmacology

Carprofen is a non-steroidal anti-inflammatory drug (NSAID) of the propionic acid class that includes ibuprofen, naproxen, and ketoprofen. It is no longer used in the clinical setting, but is approved for use in dogs. Carprofen is non-narcotic and has characteristic analgesic and antipyretic activity approximately equipotent to indomethacin in animal models.

mechanism of action

The mechanism of action of carprofen, like that of other NSAIDs, is believed to be associated with the inhibition of cyclooxygenase activity. Two unique cyclooxygenases have been described in mammals. The constitutive cyclooxygenase, COX-1, synthesizes prostaglandins necessary for normal gastrointestinal and renal function. The inducible cyclooxygenase, COX-2, generates prostaglandins involved in inflammation. Inhibition of COX-1 is thought to be associated with gastrointestinal and renal toxicity while inhibition of COX-2 provides anti-inflammatory activity. In an in vitro study using canine cell cultures, carprofen demonstrated selective inhibition of COX-2 versus COX-1.

toxicity

Symptoms of NSAID overdose include dizziness and nystagmus. Oral LD₅₀ in mouse and rat is 282 mg/kg and 149 mg/kg, respectively.

biotransformation

Hepatic.

absorption

Rapidly and nearly completely absorbed (more than 90% bioavailable) when administered orally.

half life

Approximately 8 hours (range 4.5–9.8 hours) in dogs.