A 35-year-old man complains of chest pain, which began following the use of cocaine 30 minutes prior to arrival. The patient describes severe substernal chest pressure, radiating to the left arm and jaw. It is associated with shortness of breath. Initial vital signs: temperature 100.4°F, heart rate 120/min, respiratory rate 20/min, blood pressure 185/100 mm Hg, pulse oximetry 98% on room air. An ECG is consistent with acute myocardial infarction. A drug which is contraindicated is:
Cocaine-associated chest pain and cocaine-induced myocardial infarction are treated identically to non–cocaine-associated acute coronary syndromes with one important exception: beta-blockers are contraindicated in patients who have taken cocaine. The use of cocaine leads to increased neurotransmitter release into the neuronal synapse. It also inhibits the reuptake of both norepinephrine and epinephrine. This leads to increased adrenergic tone causing tachycardia, hypertension, and hyperthermia. Cocaine has been shown to both accelerate atherosclerosis and cause vasoconstriction of the coronary arteries. Use of beta-blockers in the setting of cocaine use can lead to unopposed alpha-agonism, which can increase the toxic effects by worsening tachycardia, hypertension, and vasoconstriction.