Piroxicam is a potent, long-acting, non-steroidal anti-inflammatory drug (NSAID) of the oxicam class. It is a non-selective cyclooxygenase (COX) inhibitor with significant anti-inflammatory, analgesic, and antipyretic properties. In the Indian market, the 20mg/ml concentration is primarily available as a solution for intramuscular injection, used for rapid relief in acute painful and inflammatory conditions. It is known for its long half-life, allowing for once-daily dosing.
Adult: Oral: 20 mg once daily, usually with food. For acute gout: 40 mg once daily on first day, then 20 mg once daily for 7-14 days. Intramuscular (20mg/ml): 20 mg (1 ml) as a single deep IM injection into a large muscle mass. May be repeated after 24 hours if necessary. Should not exceed 2-3 days of IM therapy. Switch to oral therapy as soon as possible.
Note: Oral: Take with food or a full glass of milk/water to minimize GI upset. Do not crush or chew capsules. IM Injection: Administer as a deep intramuscular injection into the gluteal or deltoid muscle. Aspirate before injection to avoid intravascular administration. Do not inject intravenously, subcutaneously, or intra-articularly (for this 20mg/ml formulation). Rotate injection sites. The vial/ampoule is for single use only.
Piroxicam exerts its therapeutic effects by non-selectively inhibiting the enzyme cyclooxygenase (COX), both COX-1 and COX-2 isoforms. This inhibition blocks the conversion of arachidonic acid to prostaglandin G2 (PGG2) and subsequently to prostaglandin H2 (PGH2), the precursors of prostanoids including prostaglandins (PGs), prostacyclin, and thromboxanes. The reduction in prostaglandin synthesis, particularly PGE2, at the site of inflammation mediates its anti-inflammatory, analgesic, and antipyretic actions.
Pregnancy: Category C (first and second trimester): Use only if potential benefit justifies potential risk to fetus. Avoid in third trimester (Category D) due to risk of premature closure of ductus arteriosus, oligohydramnios, and inhibition of labor.
Driving: May cause dizziness, drowsiness, vertigo, or blurred vision. Patients should be cautioned about operating machinery or driving until they know how the drug affects them.
| Anticoagulants (Warfarin, Acenocoumarol) | Increased risk of bleeding due to antiplatelet effect and displacement from protein binding. | Major |
| Anti-platelets (Aspirin, Clopidogrel) | Additive risk of GI bleeding. | Major |
| Other NSAIDs or Corticosteroids (e.g., Prednisolone) | Greatly increased risk of GI ulceration and bleeding. | Major |
| ACE Inhibitors (e.g., Ramipril, Enalapril) / ARBs (e.g., Telmisartan) | Reduced antihypertensive effect; increased risk of renal impairment. | Moderate |
| Diuretics (Furosemide, Hydrochlorothiazide) | Reduced diuretic and antihypertensive efficacy; risk of renal failure. | Moderate |
| Lithium | Decreased renal clearance of lithium, leading to toxicity. | Major |
| Methotrexate | Reduced renal clearance of methotrexate, increasing risk of bone marrow toxicity and GI toxicity. | Major |
| Cyclosporine, Tacrolimus | Increased risk of nephrotoxicity. | Major |
| SSRIs (e.g., Sertraline, Escitalopram) | Increased risk of upper GI bleeding. | Moderate |
| Sulfonylureas (e.g., Glimepiride) | Enhanced hypoglycemic effect (displacement from protein binding). | Moderate |
| Phenytoin | Displacement from protein binding may increase phenytoin levels. | Moderate |
Same composition (Piroxicam (20mg/ml)), different brands: