Common Early Symptoms
Immediate signs of aspirin overdose, often appearing within hours of ingestion, include tinnitus (ringing in the ears), nausea, vomiting, and rapid breathing (hyperventilation). These stem from aspirin's effects on the ears, stomach, and respiratory center in the brain.[1][2]
Why These Signs Occur
Aspirin (acetylsalicylic acid) irritates the gastrointestinal tract, causing nausea and vomiting. At high doses, it stimulates the respiratory center, leading to hyperpnea—deep, fast breathing that compensates for metabolic acidosis. Tinnitus results from salicylate toxicity affecting the cochlea.[1][3]
Progression to Severe Signs
If untreated, symptoms escalate quickly: vertigo, sweating, confusion, fever, dehydration from vomiting, and in children, rapid onset of lethargy or seizures. Blood salicylate levels above 30 mg/dL confirm toxicity, but symptoms can appear at lower levels in acute overdose.[2][4]
What to Do If Suspected
Seek emergency care immediately—do not induce vomiting. Activated charcoal may be given if ingestion was recent, followed by monitoring for acidosis, electrolytes, and possible hemodialysis in severe cases. Symptoms can worsen rapidly, especially in young children or those with liver issues.[1][4]
Risk Factors and Vulnerable Groups
Overdose risk rises with intentional ingestion, chronic high dosing in elderly patients, or combinations with alcohol/dehydrants. Children under 12 and adults over 65 show faster, more severe symptoms due to immature or reduced drug clearance.[3][2]
Sources
[1]: CDC - Aspirin Poisoning
[2]: MedlinePlus - Aspirin Overdose
[3]: StatPearls - Salicylate Toxicity
[4]: UpToDate - Salicylate Poisoning