vi medicine informatics
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Appropriate drug treatment of a non–ST-segment elevation MI (NSTEMI) in the emergency department includes aspirin, anticoagulants, ADP receptor inhibitors, β-blockers, angiotensin-converting enzyme (ACE) inhibitors, and analgesia (eg, morphine, nitroglycerin). Patients with an ST-segment elevation MI (STEMI) should also undergo reperfusion therapy with either fibrinolytics or (preferred) percutaneous coronary intervention. β-Blockers are part of the gold standard treatment for MI, but they, especially the nonselective ones, are absolutely contraindicated for this patient because administration in the context of recent cocaine use would result in unopposed alpha effects. By blocking presynaptic reuptake of norepinephrine and increasing release of catecholamines from the adrenal glands, cocaine results in a high degree of adrenergic activity. β-blockers block the β2 receptors which normally vasodilate the arteries. Without this effect, the adrenergic activity isolate the effects of α-receptors, in particular serving as an α1-agonist that increases vascular smooth muscle contraction. An increase in vascular constriction would cause an increase in hypertension and further ischemia in the coronary arteries. Therefore treatment with a β-blocker should be avoided as this would result in unopposed α-adrenergic effects.
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