Which of the following symptoms is NOT associated with aspirin overdose?

Aspirin overdose is characterized by a variety of symptoms due to its pharmacologic effects and metabolic disturbances. Among the notable symptoms associated with aspirin toxicity are hyperventilation, seizures, and lactic acidosis.

Hyperventilation occurs because aspirin stimulates the respiratory center, leading to respiratory alkalosis initially, which can subsequently cause compensatory metabolic acidosis as the overdose progresses. Seizures are a central nervous system manifestation that can result from the direct effects of salicylates on the brain, especially in severe cases. Lactic acidosis can develop due to tissue hypoxia and increased anaerobic metabolism, which is often seen in cases of aspirin toxicity as well, especially where there is significant metabolic derangement.

In stark contrast, bradycardia is not typically associated with aspirin overdose. Instead, aspirin may lead to a variety of cardiovascular effects, but it does not usually cause a decrease in heart rate; rather, tachycardia can occur in response to metabolic disturbances. Therefore, among the options presented, bradycardia stands out as the symptom that does not align with the common manifestations of aspirin overdose.