Because they increase the force of the heartbeat, all three catecholamines may produce an excessively rapid heart rate. Palpitations produced by epinephrine and isoproterenol are accompanied by tachycardia, whereas those produced by norepinephrine usually are accompanied by bradycardia owing to reflex slowing of the heart. Headache and tremor are also common. Epinephrine is especially likely to produce anxiety, fear, and nervousness.
The greatest hazards of accidental overdosage with epinephrine and norepinephrine are cardiac arrhythmias, excessive hypertension, and acute pulmonary edema. Large doses of isoproterenol can produce such excessive cardiac stimulation, combined with a decrease in diastolic blood pressure, that coronary insufficiency may result. It also may cause arrhythmias and ventricular fibrillation. Tissue sloughing and necrosis due to severe local ischemia may follow extravasation of norepi-nephrine at its injection site.
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Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...