common adverse reactions, reported in at least 5% of overdose cases, included vomiting, somnolence, and tremor. other clinically important signs and symptoms of overdoses include acidosis, aggression, atrial fibrillation, bradycardia, coma, confusion, convulsion, depressed level of consciousness, hypertension, hypokalemia, hypotension, lethargy, loss of consciousness, pneumonia aspiration, respiratory arrest, status epilepticus, and tachycardia.