Piroxicam:

  • It is a novel oxicam derivative NSAID with anti-inflammatory, analgesic and antipyretic action.
  • It occurs as white crystalline solid that is sparingly soluble in water.

MOA:

  • Like other NSAIDs, it inhibits cyclooxygenase enzyme
  • It reversible binds cyclooxygenase enzyme inhibiting prostaglandin (PG) synthesis
  • It inhibits platelet aggregation

Pharmacological Effects:

  • It possess prominent anti-inflammatory and analgesic-antipyretic activity.
  • It inhibits platelet aggregation, increases bleeding time, causes GI mucosal damage and can affect renal function.

Pharmacokinetics:

  • It is well-absorbed after oral administration.
  • Though presence of food in stomach may decrease the rate of absorption, the total amount of piroxicam absorbed remains same.
  • It is highly bound to plasma protein, largely metabolized in liver by hydroxylation and glucuronide conjugation.
  • It is excreted in urine, bile and also in milk in very low concentration (about 1%).

Side effects/Adverse effects:

  • Adverse GI reactions are most common form of piroxicam effects.
  • GI bleeding, peptic ulceration, and perforation in dogs
  • Renal papillary necrosis, peritonitis, CNS effect
  • Tinnitus, edema, pruritus, and rash

Drug Interaction:

  • Concurrent use with aspirin or other NSAID increases the potential of adverse effects.
  • It can displace or get displaced by warfarin and phenylbutazone.

Contraindications and precautions:

  • It shouldnot be used in patients with history of or pre-existing GI ulcers or bleeding disorders.
  • It is contraindicated in patients with hypersensitivity to it.
  • It should be used cautiously in patients with CHF.

Indications:

  • It is used mainly in dogs in pain and inflammation associated with degenerative joint disease; eg; osteoarthritis
  • In some anticancer protocols to treat or suppress certain neoplasia such as transitional cell carcinoma of bladder, squamous cell carcinoma and mammary adenocarcinoma.
  • In human, it is used in rheumatoid arthritis, osteoarthritis, post-operative pain and acute gout.

Dose:

  • Dogs: 0.3 mg/kg, PO, on alternate days