Death temporally related to the use of a Beta adrenergic receptor antagonist in cocaine associated myocardial infarction.

INTRODUCTION: Although it is commonly stated that the use of beta adrenergic receptor antagonists is contraindicated in patients with cocaine toxicity, actual clinical evidence of harm is lacking. This case helps to highlight the risks of beta adrenergic receptor antagonists in patients with chest pain associated with cocaine use.

CASE REPORT: A 54-year-old man was brought to the emergency department (ED) complaining of chest pain after using approximately 1 gram of intranasal cocaine. Aspirin and nitroglycerin spray relieved his pain. Although he remained pain free, tachycardia persisted despite 15 mg of diazepam intravenously. Nearly two hours after presentation, a total of 5 mg of metoprolol was given for persistent tachycardia (115/minute) and an elevated troponin. Shortly thereafter, the patient complained of crushing substernal chest pain, developed pulseless electrical activity, and could not be resuscitated.

DISCUSSION: The administration of beta adrenergic receptor antagonists exacerbates cocaine-induced lethality in animals. In humans given smaller doses of cocaine, beta adrenergic receptor antagonists exacerbate coronary vasoconstriction. Both effects are presumed to occur through unopposed alpha adrenergic receptor agonism. Despite these data, actual cases describing adverse effects in cocaine users given beta adrenergic receptor antagonists are uncommon. This case supports the potential lethality of a cocaine-beta adrenergic receptor antagonist interaction.