norepinephrine bitartrate

norepinephrine bitartrate,

a commercial preparation of an endogenous agonist of alpha-1, alpha-2, and beta-1 adrenergic.

indication It is prescribed in the treatment of shock that persists after hypovolemia has been corrected.

contraindications Known hypersensitivity to this drug or bisulfite preservatives prohibits its use. Hypovolemia and vascular thrombosis are contraindications unless it is used as a short-term lifesaving procedure to maintain perfusion of vital organs. It is not used in conjunction with cyclopropane or halothane anesthesia because of the increased risk of arrhythmia.

adverse effects Among the more serious adverse effects are local tissue necrosis at the site of injection, bradycardia, and headache. Overdosage can cause hypertension, peripheral or cardiac ischemia or infarctions, hemorrhagic strokes, and convulsions.

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norepinephrine bitartrate Warning - High-alert drug!

Levophed

Pharmacologic class: Sympathomimetic

Therapeutic class: Alpha- and beta-adrenergic agonist, cardiac stimulant, vasopressor

Pregnancy risk category C

FDA Boxed Warning

• If extravasation occurs, infiltrate area promptly with 10 to 15 ml of saline solution containing 5 to 10 mg phentolamine to prevent sloughing and necrosis. Use syringe with fine hypodermic needle, and infiltrate solution liberally throughout area. Give phentolamine as soon as possible; its sympathetic blockade causes immediate local hyperemic changes if area is infiltrated within 12 hours.

Action

Stimulates beta₁ and alpha₁ receptors in sympathetic nervous system, causing vasoconstriction, increased blood pressure, enhanced contractility, and decreased heart rate

Availability

Injection: 1 mg/ml

⊘Indications and dosages

➣ Severe hypotension

Adults: 8 to 12 mcg/minute I.V.; then titrate based on blood pressure response. For maintenance, 2 to 4 mcg/minute.

Contraindications

• Concurrent cyclopropane or halothane anesthesia
• Hypotension caused by blood volume deficit (except in emergencies until blood volume replacement is completed), profound hypoxia or hypercarbia
• Mesenteric or peripheral vascular thrombosis

Precautions

Use cautiously in:
• sulfite sensitivity (some products), especially in asthmatic patients
• arterial embolism, cardiac disease, peripheral vascular disease, hypertension, hyperthyroidism
• patients receiving MAO inhibitors or tricyclic antidepressants concurrently
• elderly patients
• pregnant or breastfeeding patients
• children (safety and efficacy not established).

Administration

• Mix with dextrose 5% in water or dextrose 5% in normal saline solution.
• Inspect solution to make sure it's clear and colorless. Don't infuse if it's brown or pink.
• Administer through infusion pump. Titrate infusion rate to achieve and maintain low-normal systolic blood pressure (80 to 100 mm Hg).
• Continue infusion until adequate blood pressure and tissue perfusion persist without drug therapy.
• Gradually titrate dosage downward.
• To avoid extravasation, administer only into large vein (antecubital) or through central line. Don't use femoral vein in patients who are elderly or have occlusive vascular disorders.
☞ To prevent delivery of large drug concentrations, avoid line stasis and flushing.

Route	Onset	Peak	Duration
I.V.	Immediate	Immediate	1-2 min after infusion ends

Adverse reactions

CNS: headache, anxiety

CV: bradycardia, severe hypertension, arrhythmias

Respiratory: respiratory difficulty

Skin: irritation with extravasation, necrosis

Other: ischemic injury

Interactions

Drug-drug. Alpha-adrenergic blockers: antagonism of norepinephrine effects

Antihistamines, ergot alkaloids, guanethidine, MAO inhibitors, oxytocin, tricyclic antidepressants: severe hypertension

Bretylium, inhalation anesthetics: increased risk of arrhythmias

Patient monitoring

☞ Check blood pressure every 2 minutes until desired pressure is achieved. Recheck every 5 minutes for duration of infusion.
• Maintain continuous ECG monitoring and blood pressure monitoring.
☞ Be aware that headache may signal extreme hypertension and overdose.
• Monitor infusion site for extravasation.
☞ Watch for signs and symptoms of peripheral vascular insufficiency (decreased capillary refill, pale to cyanotic to black skin color).
☞ Never leave patient unattended during infusion.

Patient teaching

• When patient is alert, explain why he's receiving drug.
• Reassure patient he'll be monitored continuously until he's stable.