epinephrine /ep′ənef″rin/ [Gk, epi + nephros, kidney] , an endogenous adrenal hormone and synthetic adrenergic agent. It acts as an agonist at alpha-1, alpha-2, beta-1, and beta-2 receptors. Also called adrenaline. ▪ INDICATIONS: It is prescribed to treat anaphylaxis, acute bronchial spasm, and nasal congestion and to increase the effectiveness of a local anesthetic. ▪ CONTRAINDICATIONS: Known hypersensitivity to this drug prohibits its use. It must be used with extreme caution with patients who have cardiac disease or conditions. ▪ ADVERSE EFFECTS: Among the most serious adverse effects are arrhythmias, increases in blood pressure, rebound congestion (when it is used as a decongestant), tachycardia, and nervousness.