Cardiovascular collapse and propranolol overdose.

We report three cases of propranolol overdose in two patients, both of whom suffered cardiovascular collapse after receiving an emetic compound in a hospital's casualty department. Such a collapse may be caused by vagal activity in the presence of sympathetic beta-blockade. We recommend the administration of atropine, which may increase vagal tone, before a patient receives an emetic compound, or undergoes gastric lavage or endotracheal intubation.