VCP 511: Medicine Section

ACETAMINOPHEN

1. How does the pet get them?
• Acetaminophen is presented as tablets/ capsules/ liquids either single or combined
2. What happens if ingested?
• Hepatotoxicosis occurs with doses of 50 to 100 mg/kg
• Methemoglobinemia occurs with dose200 mg/kg.
• Facial and paw edema
• Transient keratoconjunctivitis sicca
3. How to treat?
1. Initiate gastric decontamination procedures followed with 5% N-acetylcysteine (NAC) * solution administered 140 mg/kg NAC orally as a loading dose, followed by 70 mg/kg every six hours for at least seven doses.
2. Fluids to maintain hydration
3. Adjunctive therapies
4. Ascorbic acid, which helps reduce methemoglobin to hemoglobin
5. Cimetidine, which inhibits cytochrome P-450 oxidation in the liver and may help reduce acetaminophen metabolism;
   S-adenosylmethionine (SAM-e) in patients in which long-term treatment of hepatic injury is needed.
6. Monitor serum chemistry profile parameters
7. Monitor tear production - administer artificial tears and cyclosporine if needed.
8. The facial and paw edema will resolve on its own
9. *NAC is not labeled for intravenous administration, it can be given intravenously in life-threatening situations by using a bacteriostatic filter (0.2 µm).