<p>Poisoning due to an overdose of metoprolol may lead to severe hypotension, sinus&nbsp;bradycardia, atrioventricular block, heart failure, cardiogenic shock, cardiac arrest,&nbsp;bronchospasm, impairment of consciousness, coma, nausea, vomiting, cyanosis, hypoglycaemia and, occasionally, hyperkalaemia. The first manifestations usually appear 20 minutes to 2 hours&nbsp;after drug ingestion. Treatment: Treatment should include close monitoring of cardiovascular,&nbsp;respiratory and renal function, and blood glucose and electrolytes. Further absorption may be&nbsp;prevented by induction of vomiting, gastric lavage or administration of activated-charcoal if&nbsp;ingestion is recent. Cardiovascular complications should be treated symptomatically, which may&nbsp;require the use of sympathomimetic agents (e.g. noradrenaline, metaramionl), atropine or&nbsp;inotropic agents (e.g. dopamine, dobutamine). Temporary pacing may be required for AV block.&nbsp;Glucagon can reverse the effects of excessive B-blockade, given in a dose of 1-10 mg&nbsp;intravenously. Intravenous B2-stimulants e.g. terbutaline may be required to relieve&nbsp;bronchospasm. Metoprolol cannot be effectively removed by haemodialysis.</p>