Canidryl Tablets

Indications

• Pain management in dogs
• Inflammation associated with osteoarthritis
• Post-operative pain relief

Dosage

Children: Carprofen is not indicated for use in pediatric populations; refer to the BNF for Children for appropriate veterinary dosing information.

Adults: Carprofen is not typically used in adults; refer to the BNF for specific veterinary dosing guidelines.

Mechanism of action

The mechanism of action of carprofen involves the inhibition of cyclooxygenase (COX) activity, specifically demonstrating selective inhibition of COX-2 over COX-1. COX-1 is responsible for producing prostaglandins that maintain normal gastrointestinal and renal function, while COX-2 is involved in the inflammatory response. By inhibiting COX-2, carprofen reduces the production of inflammatory prostaglandins, thereby alleviating pain and inflammation associated with various conditions.

Pharmacodynamics

Carprofen exhibits analgesic and antipyretic properties, similar in potency to indomethacin in animal models. It is classified as a non-narcotic NSAID, meaning it does not produce the sedation associated with narcotic analgesics. Its actions are primarily mediated through the inhibition of prostaglandin synthesis, leading to reduced inflammation and pain perception.

Pharmacokinetics

Carprofen is well-absorbed after oral administration and undergoes hepatic metabolism before being excreted primarily through the urine. Its pharmacokinetic profile has not been extensively detailed in humans, as its primary use is in veterinary medicine. However, in dogs, it demonstrates a half-life that allows for once or twice daily dosing, making it convenient for managing chronic pain.

Contra-indications

• Hypersensitivity to carprofen or any of its excipients
• History of gastrointestinal bleeding or ulceration
• Severe hepatic or renal impairment
• Concurrent use of other NSAIDs or corticosteroids

Adverse effects

• Gastrointestinal disturbances such as vomiting, diarrhea, and abdominal pain
• Renal toxicity, including acute kidney injury
• Hepatotoxicity
• Allergic reactions including rash and anaphylaxis
• Increased liver enzyme levels

Interactions

• Other NSAIDs may increase the risk of gastrointestinal side effects
• Anticoagulants may have enhanced effects leading to increased bleeding risk
• Diuretics may have reduced effectiveness due to renal impairment
• Corticosteroids may increase the risk of gastrointestinal toxicity

Precautions

• Use with caution in animals with pre-existing renal, hepatic, or gastrointestinal conditions
• Monitor liver and kidney function regularly during treatment
• Avoid use in pregnant or lactating animals unless deemed necessary by a veterinarian

Pregnancy

Carprofen should be used in pregnant animals only if the benefits outweigh the risks, as it may cause adverse effects on fetal development.

Breast-feeding

It is not recommended for use in lactating animals, as it may be excreted in milk and affect nursing offspring.

Storage

Store in a cool, dry place away from light. Keep out of reach of children.

Formulations

• Tablets
• Injectable solution
• Chewable tablets

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 <i>in vitro</i> study using canine cell cultures, carprofen demonstrated selective inhibition of COX-2 versus COX-1.

Pharmacodynamics

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.