Flunixin Meglumine

NSAID for visceral pain (colic), fever, musculoskeletal inflammation, and endotoxemia in horses; FDA-approved for equine use. Non-selective COX inhibitor NSAID (flunixin meglumine). Mechanism: inhibits cyclooxygenase-1 and -2 → reduces prostaglandin synthesis. Particularly effective for visceral pain (high plasma protein binding concentrates drug at inflamed viscera). Also reduces endotoxin-mediated hemodynamic changes. Aminonicotinic acid derivative. Time-dependent elimination in horses (~1.6 hr half-life). Key information NSAID. Do NOT administer intra-arterially — fatal. IV or IM use in horses; IV strongly preferred (IM causes severe muscle necrosis). Do not use in horses with GI disease — masks colic signs. Withdrawal: 4 days. Potential for right dorsal colitis with prolonged use.

Horses — IV only: administer slowly into jugular vein (do NOT give IM or SQ — tissue necrosis). Oral granules: mix into small amount of grain; ensure complete consumption. Oral paste: administer via dose syringe into back of mouth. Small animals: oral tablets — Administer with food to reduce GI adverse effects. Store at room temperature; protect from light. If a dose is missed Flunixin is typically given as a single dose or short course. Contact your veterinarian before giving an additional dose if one was missed.

GI: gastric/right dorsal colonic ulceration (horses — particularly right dorsal colitis with overdose). Renal: acute tubular necrosis (dehydration). Perivascular injection necrosis (horses — IV route only recommended). Hepatotoxicity. Hematologic: platelet dysfunction. Do not combine with corticosteroids or other NSAIDs.

For animals Horses: IV route only (IM/SQ causes severe tissue necrosis). Monitor for GI ulceration; use with caution in animals with GI disease. — right dorsal colitis risk with overdose or prolonged use in horses. Monitor renal function, hydration status, and urine output. Do not use concurrently with other NSAIDs or corticosteroids. Foals: use with caution. Use with caution in pregnant animals. For people handling this medication Wear gloves when handling. Wash hands thoroughly with soap and water after handling. NSAID injectable — avoid skin contact. If using oral paste, wear gloves. Avoid contact with eyes; if contact occurs, flush with water for 15 minutes and seek medical attention. Keep out of reach of children. Contact Poison Control if ingested.

Contact your veterinarian or emergency clinic immediately. Overdose causes GI ulceration, kidney failure, and GI bleeding. IV fluid support and GI protectants are required.