Myocardial injury after phenylpropanolamine ingestion

Three patients developed clinical evidence of myocardial injury after acute ingestion of phenylpropanolamine, a sympathomimetic amine found in a large number of decongestant and appetite suppressant formulations. Increases in the serum creatine kinase and MB isoenzyme levels, ventricular arrhythmias, and electrocardiographic repolarisation abnormalities were seen. Excessive catecholamine stimulation has been shown to produce acute myocardial necrosis experimentally, and a similar mechanism may be present in these patients.

Incidence of late arrhythmias following tricyclic antidepressant overdose

The case records of 129 patients hospitalized because of tricyclic antidepressant (TCA) poisoning were analyzed to determine the incidence of late arrhythmias. All patients who developed cardiovascular or central nervous system complications of TCA overdose did so within 1 h of admission. No patients developed arrhythmias once they became alert and had a normal cardiogram for 1 h; a 24-h period of inpatient monitoring is suggested as sufficient follow-up for such patients provided they have no underlying cardiac disease.

Asystole complicating physostigmine treatment of tricyclic antidepressant overdose

Physostigmine is a commonly used therapy for the anticholinergic manifestations of tricyclic antidepressant (TCA) overdose. We describe two patients with TCA toxicity who developed asystole following the administration of physostigmine to treat seizures.

Potentiation of warfarin anticoagulation by sulfisoxazole

The prothrombin time (PT) of a patient undergoing warfarin sodium anticoagulation became elevated when sulfisoxazole was given concurrently. The warfarin dose index is used to demonstrate that this PT prolongation was the result of a warfarin-sulfisoxazole interaction. The mechanism of this interaction may involve displacement of warfarin from serum albumin. Sulfisoxazole should be used cautiously, if at all, in patients taking warfarin.