Acetaminophen – Aspirin – Ibuprofen – Naproxen – Carprofen – Deracoxib – Meloxicam – Firocoxib
ACETAMINOPHEN (Tylenol)
Dogs:
>50 mg/kg: be concerned
>100 mg/kg: signs common
>200 mg/kg: methemoglobinemia
Cats:
As low as 10 mg/kg
50-100 mg/kg: signs common
Mechanism of toxicity:
NAPQI = toxic metabolite (binds to proteins, damages cell membranes via lipid peroxidation)
PAP is another free radical leading to methemoglobinemia
Dogs: hepatocellular injury and necrosis more common
Cats: methemoglobinemia more common. Cat hemoglobin has 8 sulfhydryl groups vs. only 4 in dogs, which predisposes them to oxidative injury.
Treatment:
Emesis +/- gastric lavage
Activated charcoal (within 4-6 h)
N-acetylcysteine (NAC) considered the antidote; consider SAMe if NAC unavailable
For methemoglobinemia: methylene blue or ascorbic acid
Transfusions if clinical
ASPIRIN
Dogs:
25 mg/kg: gastric bleeding
>150 mg/kg: decontamination and gastrointestinal protectionI
>400 mg/kg: liver necrosis, acidosis, seizures
Treatment:
Emesis if appropriate
Activated charcoal
GI protectants +/- misoprostol
Consider baseline chem, PCV/TP, lytes. AKI uncommon.
IBUPROFEN (Advil)
Dogs:
8-16 mg/kg: mild gastritis
50-100 mg/kg: mild to severe GI ulcer, vomiting, abdominal pain
> 100 – 250 mg/kg: AKI
> 300 mg/kg: Fatalities. CNS effects such as seizure, ataxia, and coma can occur.
Cats:
> 87 mg/kg AKI
Treatment:
Induce vomiting
Activated charcoal: repeat doses due to enterohepatic recirculation
IV fluids: maintain hydration & perfusion for 48h
GI protectants: 5-7 days
+/- Misoprostol for 3-5 days
Chemistry panel: Baseline, 36, 48, and 72 h recommended
NAPROXEN (Aleve)
Dogs:
>5 mg/kg
22 mg/kg PO x 3 days = duodenal ulcers, perforations, peritonitis
>10-25mg/kg: AKI
Treatment:
Induce vomiting
Activated charcoal: repeat doses due to extensive enterohepatic recirculation
Remember: half-life is ~70 hours!
IV fluids: maintain hydration & perfusion for at least 72 hours (b/c of long half-life)
GI protectants for 10-14 days.
CARPROFEN (Rimadyl, Vetprofen)
Dog:
>20 mg/kg: vomiting, GI ulcers
>40 mg/kg: AKI
Cat:
4 mg/kg: GI
8 mg/kg: AKI
Treatment:
Induce vomiting
Activated charcoal, consider repeating
GI protectants for 14 days; consider misoprostol
IV fluids: maintain hydration & perfusion for 48-72h
Chemistry panel: Baseline, 48h, and 72h
DERACOXIB (Deramaxx)
Dogs:
>15mg/kg: GI
> 30mg/kg: AKI
Treatment:
Activated charcoal x1
IV fluids: maintain hydration & perfusion
GI protectants: 7 days
Kidney values: Baseline and 48h
MELOXICAM (Metacam)
Dogs:
1mg/kg: GI ulcers
2mg/kg: GI ulcers and AKI
Cats: Any overdose; consider possible AKI
Treatment:
Induce vomiting
Activated charcoal
IV fluids: maintain hydration & perfusion for at least 48h
Renal values: baseline, then q 24 hours for 2-3 days
GI protectants for 5-7 days
SAM-e
Recheck kidney and liver values and U/A in 7 days
FIROCOXIB (Previcox)
Dogs:
25mg/kg: GI ulcers, vomiting
>40mg/kg: AKI
Treatment:
May not need to induce vomiting, unless it JUST happened b/c tablets rapidly dissolve
Activated charcoal x1
IV fluids: maintain hydration & perfusion for 48h
GI protectants 7-10 days
Chemistry panel: Baseline & 48h
TREATMENT CONSIDERATIONS:
Recall that many NSAIDs are highly protein-bound, which limits glomerular filtration & urinary loss.
Attempts to “flush” or “diuresis” NSAIDs with high rates of IV fluid is ineffective and may lead to fluid overload and AKI.
Activated charcoal is not benign and can lead to severe hypernatremia even without sorbitol. Multiple doses of activated charcoal may not be necessary (ref) although further studies are needed.
Massive exposures can benefit from extracorporeal therapies such as TPE, IHD, and CRRT. Consult with your closest renal replacement unit.
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