Norepinephrine (Levarterenol)

A to Z Drug Facts

 Action Stimulates alpha-receptors in arterial and venous beds and beta₁ receptors of heart, resulting in peripheral vasoconstriction and stimulation of heart rate and contractility. Coronary vasodilation occurs secondary to enhanced myocardial contractility.

 Indications Restoration of blood pressure in certain acute hypotensive states; adjunct in treatment of cardiac arrest and profound hypotension.

 Contraindications Hypovolemic states, except temporarily until blood volume replacement is accomplished; mesenteric or peripheral vascular thrombosis, unless essential; generally contraindicated during cyclopropane and halothane anesthesia; profound hypoxia or hypercarbia.

 Route/Dosage

Acute Hypotensive States

ADULTS: IV 2 to 3 mL/min of 4 mcg base/mL solution (8 to 12 mcg/min); adjust to response. Higher concentration (up to 16 mcg/mL) may be used in fluid-restricted patients. Usual maintenance dose is 2 to 4 mcg/min, but higher doses and prolonged therapy may be needed.

 Interactions

Blood or plasma: Chemically incompatible with norepinephrine. Furazolidone, guanethidine, MAO inhibitors, methyldopa, rauwolfia alkaloids: May increase pressor response, resulting in severe hypertension. Normal saline: Norepinephrine may lose potency in normal saline solution. Oxytocic drugs: May cause severe, persistent hypertension. Phenothiazines (eg, chlorpromazine): May decrease pressor effect. Tricyclic antidepressants: May increase pressor response.

 Lab Test Interferences None well documented.

 Adverse Reactions

CV: Hypotension; increased peripheral vascular resistance; decreased carbon monoxide; precordial pain; ventricular arrhythmias; reflex bradycardia. RESP: Respiratory difficulties. CNS: Headache; dizziness; tremor; insomnia; anxiety. META: Metabolic acidosis; hyperglycemia. OTHER: Gangrene (when infused into small vein); thyroid enlargement; irritation from extravasation; decreased urinary output.

 Precautions

Pregnancy: Category D. Lactation: Undetermined. Children: Safety and efficacy not established. Extravasation: Avoid by infusion into large vein and monitoring carefully. Sulfite sensitivity: Use caution in sulfite-sensitive individuals; some preparations contain sodium bisulfite.

 Administration/Storage

• Administer in D5W or 5% dextrose in saline. Do not prepare infusion with normal saline alone because doing so may cause degradation.
• Use infusion pump and plastic catheter. Enter antecubital or other large vein.
• Do not discontinue therapy abruptly.
• Discard solution after 24 hr.
• Store undiluted solution at room temperature. Protect from light.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies.
• Obtain baseline vital signs, neurological assessment, urinary output, and ECG.
• Monitor vital signs, ECG, I&O, and neurological status regularly during therapy.
• Monitor for cyanosis: Bluish skin color and cold extremities.
• Assess for signs of extravasation (eg, blanching and coolness of skin over vein) at infusion site. If this occurs, notify physician immediately and change infusion site as soon as possible. Have phentolamine readily available for local infiltration in case extravasation occurs.

 Patient/Family Education

• Advise patient to notify nurse if IV site feels cool or painful.
• Instruct patient to report the following symptoms to physician: Dizziness, nausea, syncope, abdominal pain, chest pain or confusion.
• Caution patient to avoid sudden position changes to prevent orthostatic hypotension.

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Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts