piroxicam

Piroxicam is a nonsteroidal anti-inflammatory drug (NSAID) in the enolic acid class used to relieve signs and symptoms of inflammatory joint diseases and other rheumatic conditions. It is typically prescribed for rheumatoid arthritis, osteoarthritis, and related musculoskeletal pain, with consideration given to its long duration of action.

Mechanism of action: Piroxicam inhibits cyclooxygenase enzymes COX-1 and COX-2, reducing synthesis of prostaglandins involved in inflammation, pain, and fever. This non-selective COX inhibition accounts for anti-inflammatory, analgesic, and antipyretic effects, but also contributes to gastrointestinal and renal adverse effects.

Pharmacokinetics: Administered orally; piroxicam has a relatively long half-life, typically around 45 to 50 hours, allowing once-daily dosing in many regimens. It is highly bound to plasma proteins and undergoes hepatic metabolism, with metabolites excreted in urine and feces.

Dosing and administration: Typical adult dosing starts at 20 mg once daily, with adjustments up to 20 mg twice daily depending on response and tolerability. Treatment should be used at the lowest effective dose for the shortest duration. Caution is advised in elderly patients due to increased GI and cardiovascular risks. Contraindicated in active GI ulcers or bleeding, severe hepatic or renal impairment, hypersensitivity to NSAIDs, and in the third trimester of pregnancy.

Adverse effects and interactions: Common adverse effects include dyspepsia, nausea, abdominal pain, and gastroesophageal ulcers; more serious risks include GI bleeding, renal impairment, hypertension, and heart failure exacerbation. Piroxicam can interact with anticoagulants, other NSAIDs, corticosteroids, diuretics, and ACE inhibitors, potentially increasing bleeding risk and reducing antihypertensive efficacy. Patients should be monitored for signs of GI intolerance and renal function.