Piroxicam exerts its therapeutic effects through its action on the cyclooxygenase (COX) enzymes. Its key mechanisms include:

1. Inhibition of Cyclooxygenase (COX) Enzymes:
   • Piroxicam inhibits both COX-1 and COX-2 enzymes, which are involved in the synthesis of prostaglandins and thromboxanes.
   • COX-1 is responsible for the production of prostaglandins that protect the gastric mucosa and regulate platelet function.
   • COX-2 is induced during inflammation and is responsible for the production of prostaglandins that mediate pain, inflammation, and fever.
2. Reduction of Prostaglandin Synthesis:
   • By inhibiting COX enzymes, piroxicam reduces the production of prostaglandins, leading to decreased inflammation, pain, and fever.
3. Antipyretic Effects:
   • Piroxicam reduces fever by inhibiting prostaglandin synthesis in the hypothalamus, which regulates body temperature.

Piroxicam is approved for a variety of clinical conditions, including:

1. Osteoarthritis:
   • Management of pain and inflammation associated with osteoarthritis.
2. Rheumatoid Arthritis:
   • Treatment of pain and inflammation in rheumatoid arthritis.
3. Ankylosing Spondylitis:
   • Management of pain and inflammation in ankylosing spondylitis.
4. Off-Label Uses:
   • Management of chronic pain conditions (e.g., low back pain).
   • Adjunctive therapy for dental pain.

The dosage of piroxicam varies depending on the indication, patient response, and tolerability. The following dosing guidelines are based on the British National Formulary (BNF) and clinical pharmacology references:

1. Adults:
   • Oral: 10–20 mg once daily, not exceeding 20 mg daily.
   • Topical: Apply 2–4 g of gel to the affected area 3–4 times daily.
2. Elderly Patients:
   • Lower doses (10 mg once daily) are recommended due to increased sensitivity to side effects.

Important Considerations:

• Piroxicam is available in oral capsules, tablets, and topical gel formulations.
• Dose adjustments may be necessary for patients with hepatic or renal impairment.
• Piroxicam should be taken with food or milk to minimize gastrointestinal side effects.

Piroxicam is generally well-tolerated, but it is associated with a range of side effects, some of which can be serious. Common side effects include:

1. Gastrointestinal:
   • Nausea, vomiting, dyspepsia, and abdominal pain.
   • Gastric ulcers and gastrointestinal bleeding (rare but serious).
2. Cardiovascular:
   • Increased risk of myocardial infarction and stroke, particularly with long-term use or high doses.
3. Renal:
   • Acute kidney injury and interstitial nephritis (rare).
4. Other:
   • Headache, dizziness, and rash.

Serious Side Effects:

• Gastrointestinal Bleeding: Particularly in elderly patients or those with a history of peptic ulcer disease.
• Hypersensitivity Reactions: Stevens-Johnson syndrome (SJS) and anaphylaxis (rare).

Hepatotoxicity: Elevated liver enzymes and, rarely, severe liver damage

Piroxicam requires careful monitoring and adherence to specific precautions to ensure patient safety:

1. Gastrointestinal Risk:
   • Use with caution in patients with a history of peptic ulcer disease or gastrointestinal bleeding. Consider concomitant use of a proton pump inhibitor (PPI) for gastroprotection.
2. Cardiovascular Risk:
   • Use with caution in patients with a history of cardiovascular disease. Regular monitoring of cardiovascular health is recommended.
3. Renal Impairment:
   • Use with caution in patients with impaired kidney function. Avoid use in severe renal impairment (CrCl <30 mL/min).
4. Pregnancy and Lactation:
   • Piroxicam should be avoided during the third trimester of pregnancy due to the risk of premature closure of the ductus arteriosus. It is excreted in breast milk, so breastfeeding is generally not recommended.
5. Elderly Patients:
   • Lower doses may be required due to increased sensitivity to side effects, particularly gastrointestinal and renal.

Piroxicam has a significant potential for drug interactions due to its effects on prostaglandin synthesis and metabolism. Key interactions include:

1. Anticoagulants:
   • Piroxicam may enhance the anticoagulant effects of warfarin, increasing the risk of bleeding.
2. Other NSAIDs:
   • Concurrent use with other NSAIDs increases the risk of gastrointestinal side effects.
3. Antihypertensives:
   • Piroxicam may reduce the efficacy of antihypertensive medications, such as ACE inhibitors and beta-blockers.
4. Diuretics:
   • Piroxicam may reduce the diuretic and antihypertensive effects of diuretics.
5. Lithium:
   • Piroxicam may increase lithium levels, increasing the risk of toxicity.

Piroxicam is the generic name for this medication. It is marketed under various brand names, depending on the country and manufacturer. Some examples include:

• Feldene (a well-known brand in the United States and other regions).
• Piroxicam Accord.
• Piroxicam Mylan.

Piroxicam Sandoz