aspirin poisoning

Last reviewed 03/2023

Aspirin is the most common salicylate in regular use and poisoning is common. In adults, moderate to severe toxicity may occur after taking 50 x 300 mg tablets.

Salicylates may also be found in:

  • oil of wintergreen - contains methylsalicylate; this is particularly toxic by mouth as it is rapidly absorbed; 1 teaspoonful is equivalent to 12 x 300 mg tablets of aspirin
  • various keratolytic agents eg. salicylic acid

Normally aspirin is rapidly absorbed from the stomach and the small intestine but in large doses, clearance and absorption may be slowed as the tablets adhere to form a large bolus. Blood salicylate levels may continue to rise for up to 24 hours after a massive overdose.

Toxicity occurs above 250 mg per litre.