Aspirin

What it is used for

• For analgesia
• As an antiinflammatory/antirheumatic
• For antipyrexia
• Post-Adulticide therapy for heartworm disease
• For adjunctive therapy in IMHA (antithrombotic)
• For adjunctive therapy of glomerular disease (antithrombotic)
• For adjunctive therapy with azathioprine and glucocorticoids for immune-mediated hemolytic anemia
• As an analgesic/antiinflammatory prior to elective intraocular surgery
• Reduction of platelet aggregation (e.g. IMHA)
• Analgesia, pyrexia, inflammation
• General use
• General use
• For analgesia/antipyrexia/antiinflammatory
• For analgesia/antipyrexia/antiinflammatory
• For analgesia/antipyrexia/antiinflammatory
• For prophylaxis of arterial thromboembolism (ATE)
• For prophylaxis of arterial thromboembolism
• For prevention of thromboembolism (High dose)
• For prevention of thromboembolism (Low dose)
• Reduction of platelet aggregation (low dose)
• Reduction of platelet aggregation (high dose)
• Reduction of platelet aggregation (very low dose)
• For analgesia/antipyrexia
• For analgesia/antipyrexia (Mature Cattle)
• For analgesia/antipyrexia (Calves)
• For analgesia
• For analgesia
• For analgesia (Mature Horses)
• For analgesia (Foals)
• For analgesia
• For analgesia
• For anti-platelet activity as an adjunctive treatment of laminitis
• For low grade analgesia (Rabbits)
• General use (Mice, Rats, Gerbils, Hamsters)
• General use (Guinea pigs)

How it is given

Possible side effects

• Gastric irritation (nausea, anorexia, vomiting)
• Gastrointestinal ulceration and occult blood loss
• Secondary anemia or hypoproteinemia (due to chronic GI blood loss)
• Metabolic acidosis (especially in cats)
• Hypersensitivity reactions (rare in dogs)

Cautions & contraindications

• Known hypersensitivity to salicylates
• Active gastrointestinal bleeding or ulcers
• Bleeding disorders (relative contraindication)
• Asthma (relative contraindication)
• Renal insufficiency (relative contraindication)
• Pregnancy (especially later stages; low-grade teratogen and may delay labor)
• **Hepatic and Renal Function:** Use with extreme caution and enhanced monitoring in patients with severe hepatic failure or diminished renal function. **Hypoalbuminemia:** Because aspirin is highly protein-bound, patients with low albumin may require lower dosages to prevent toxicity from increased free drug levels. **Surgical Procedures:** Due to irreversible platelet inhibition, aspirin therapy should ideally be halted one week prior to elective surgical procedures to prevent excessive bleeding. **Species Specifics:** Must be used with extreme caution in **cats** due to their inability to rapidly metabolize salicylates. Use cautiously in **neonatal animals**, as adult doses may lead to toxicity.

Drug interactions

• Alkalinizing drugs (e.g., sodium bicarbonate, acetazolamide): Significantly increases the renal excretion of salicylates; carbonic anhydrase inhibitors may cause systemic acidosis and increase CNS salicylate levels, leading to toxicity.
• Aminoglycosides: May increase the likelihood of nephrotoxicity.
• Corticosteroids: May increase salicylate clearance (decreasing serum levels) and significantly increase the risk of gastrointestinal ulceration and bleeding.
• Digoxin: Aspirin may increase plasma levels of digoxin by decreasing its clearance.
• Furosemide: May compete with renal excretion of aspirin, delaying its elimination and potentially causing toxicity at high doses.
• Heparin or Oral Anticoagulants: Increased risk of bleeding due to synergistic antiplatelet/anticoagulant effects.
• Methotrexate: Aspirin may displace methotrexate from plasma proteins, increasing the risk of methotrexate toxicity.
• Other NSAIDs: Increased risk of severe GI ulceration. A washout period of 3-10 days is recommended when switching from aspirin to a COX-2 selective NSAID.
• Phenobarbital: May increase the rate of aspirin metabolism by inducing hepatic enzymes.
• Probenecid, Sulfinpyrazone: Aspirin may antagonize the uricosuric effects of these drugs.
• Spironolactone: Aspirin may inhibit the diuretic activity of spironolactone.
• Tetracycline: Antacids in buffered aspirin may chelate tetracyclines; separate doses by at least one hour.
• Urinary Acidifying Drugs (methionine, ammonium chloride, ascorbic acid): Can decrease the urinary excretion of salicylates, potentially leading to accumulation.
• Glucocorticoids: Increased risk of GI ulceration. Do not administer concurrently (Exception: specific protocols for IMHA treatment).

Usein kysytyt kysymykset