Grapiprant

Grapiprant is a piprant-class nonsteroidal anti-inflammatory drug used for pain and inflammation associated with canine osteoarthritis. It targets a prostaglandin receptor downstream of prostaglandin synthesis. This receptor-based action gives it a different pharmacologic mechanism from the cyclooxygenase inhibitors commonly used for osteoarthritis in veterinary practice.

Group

EP4 prostaglandin-receptor antagonist

Mechanism of Action

Grapiprant selectively antagonizes the EP4 receptor for prostaglandin E2. Activation of this receptor contributes to sensory-neuron sensitization and inflammatory signaling in osteoarthritis. Blocking EP4 reduces the pain and inflammatory responses mediated through that receptor while leaving cyclooxygenase-dependent prostaglandin synthesis intact. Its therapeutic effect therefore depends on receptor antagonism rather than inhibition of prostaglandin production.

Dose Rates

Dog

Indications

• Control of pain and inflammation associated with osteoarthritis in dogs.

Contraindications

• Use cautiously with GI disease.
• Safe effective feline and equine regimens are not established.

Adverse effects

• Vomiting, diarrhea and reduced appetite

Preparations

Monitoring and Administration

Assess pain response and monitor renal/hepatic parameters during follow-up. The equine 2 mg/kg research exposure did not establish efficacy.