Symptoms: Symptoms of overdosage include marked and prolonged hypotension and bradycardia, both of which may result in decreased cardiac output.
Treatment: If the patient is seen shortly after oral ingestion, employ lavage, activated charcoal, and cathartics. Treatment is supportive. Treat cardiac failure with inotropic agents (isoproterenol, dopamine, or dobutamine) and diuretics. In patients with hypertrophic cardiomyophathy, use alpha-adenergic agents (phenylephrine HCl or metaraminol bitartrate) to maintain blood pressure; avoid isoproterenol and norepinephine. Monitor cadiac and respiratory function; elevate the extremities. Because these agents are highly protein bound, dialysis is not likely to help.