Toxic dose

Aspirin and other salicylate poisonings cause dose-dependent toxicity—see Dose-dependent toxic effects of acute aspirin ingestion for dose-dependent toxic effects of acute aspirin ingestion.

Doses of other salicylates can be converted to aspirin equivalents using conversion factors. Notably, methyl salicylate has an aspirin-dose-conversion factor of 1.4, which means as little as 4 mL of oil of wintergreen (98% methyl salicylate) can be lethal to a small child.

Chronic ingestion of more than 100 mg/kg/day of aspirin is associated with toxicity that is more likely in older patients, or patients with chronic kidney disease or chronic liver disease.

Table 1. Dose-dependent toxic effects of acute aspirin ingestion
Acute dose of aspirin	Toxic effects and severity
less than 150 mg/kg	mild toxicity
150 to 300 mg/kg	early or mild to moderate toxicity—salicylism, primary respiratory alkalosis evolving or moderate to severe toxicity—mixed respiratory alkalosis and metabolic acidosis
300 to 500 mg/kg	severe toxicity—confusion, altered conscious state, coma, seizures, mixed respiratory acidosis and metabolic acidosis (when hyperventilation can no longer compensate)
more than 500 mg/kg	potentially fatal