Norepinephrine: Description, Uses, Dosage, Interactions, Warnings and Precautions

Norepinephrine is a neurotransmitter that is secreted in response to stress.

Description

Brand name: Levarterenol, Levophed

Generic name: Norepinephrine

Drug Class: Alpha / beta-adrenergic agonists

Have you ever wondered why your heart beats faster and your palms are sweaty when you’re scared?

Those are caused by the release of norepinephrine in your body.

Norepinephrine is a chemical released by the sympathetic nervous system in response to stress. It is classified as a neurotransmitter, a chemical released from neurons. Because the release of norepinephrine affects other organs in the body, it is also known as a stress hormone.

 

Effects of stress hormones

The sympathetic nervous system triggers a commonly known response as our “fight or flight response.” When faced with a potentially dangerous situation, we must decide to stay and face whatever is intimidating or scary to us or flee as quickly as possible.

Both options require our bodies to work faster and better. This is where norepinephrine comes in.

Function

For our body to function as efficiently as possible, norepinephrine causes various changes in the function of our body. These include the following:

  • An increase in the amount of oxygen reaching our brain: helps us think more precisely and faster.
  • An increase in our heart rate: This pumps more blood around our body, helping our muscles to work faster and more efficiently.
  • An increase in glucose (or sugar) release – This extra sugar gives our muscles something to ‘feed’ on, helping them work better and faster.
  • An increase in respiratory rate: When we breathe faster, we deliver more oxygen to the body and brain. This helps our entire body to function better.
  • A shutdown of metabolic processes: Shutting down procedures, such as digestion and growth, allows blood and energy usually used for these functions to be diverted to our muscles and brain.

What is norepinephrine used for?

Norepinephrine is indicated for controlling blood pressure in certain states of acute hypotension (e.g., pheochromocytomectomy, sympathectomy, polio, spinal anesthesia, myocardial infarction, sepsis, blood transfusion, and drug reactions).

Norepinephrine is also indicated as an adjunct in treating cardiac arrest and profound hypotension.

Norepinephrine dosage

Dosage forms for adults and pediatrics as appropriate.

Solution for injection: 1 mg / ml

Acute hypotension

  • Adult:
  1. Initial: 8-12 mcg / minute of intravenous infusion (IV); titrate to effect.
  2. Maintenance: 2-4 mcg/minute of intravenous infusion (IV).
  • Pediatric:
  1. Initial: 0.05-0.1 mcg / kg / minute of intravenous infusion (IV); titrate to effect.
  2. Maximum: 1-2 mcg / kg / minute intravenous infusion (IV).

Heart attack

  • Adult:
  1. Initial: 8-12 mcg / minute of intravenous infusion (IV); titrate to effect.
  2. Maintenance: 2-4 mcg / minute of intravenous infusion (IV).
  • Pediatric:
  1. Initial : 0.05-0.1 mcg / kg / minute of intravenous infusion (IV); titrate to effect.
  2. Maximum: 1-2 mcg / kg / minute intravenous infusion (IV).

What are the side effects associated with the use of norepinephrine?

Common side effects of norepinephrine include:

  • Slow heart rate
  • High blood pressure ( hypertension ).
  • Irregular heartbeats (arrhythmias).
  • Confusion.
  • Anxiety.
  • Shortness of breath, with or without respiratory distress.
  • Headache.
  • Nausea and vomiting
  • Perspiration.
  • Temblor.
  • Restlessness.
  • Urinary retention.
  • Intravenous (IV) fluid leak.
  • Gangrene.
  • Dizziness.
  • Soft spot.
  • Redness and swelling at the injection site.

Serious side effects of norepinephrine include:

  • Pain or burning where the injection is given.
  • Sudden numbness/weakness / cold feeling in your body.
  • Blue lips or nails.
  • Urinating less than usual or not at all.
  • Trouble breathing.
  • Dangerously high blood pressure (severe headache, blurred vision, ringing in the ears, anxiety, confusion, chest pain, shortness of breath, irregular heartbeat, seizures).

This is not a complete list of side effects, and other serious side effects can occur. Call your doctor for information and medical advice on side effects.

What other drugs interact with norepinephrine?

Suppose your doctor has directed you to use this medication for your condition. In that case, your doctor or pharmacist may already be aware of any possible drug interactions or side effects and may be monitoring you for them.

Do not start, stop, or change the dosage of this medicine or any medicine before getting information from your doctor, healthcare professional, or pharmacist.

Severe norepinephrine interactions include:

  • Isocarboxazid.
  • Linezolid.
  • Phenelzine.
  • Procarbazine.
  • Selegilina transdérmica.
  • Tranylcypromine.

Norepinephrine has severe interactions with at least 34 different medications.

Norepinephrine has moderate interactions with at least 261 different medications.

Mild norepinephrine interactions include:

  • Bendroflumethiazide.
  • Bumetanida.
  • Clorotiazida.
  • Chlortalidona.
  • Cyclopentiazide.
  • Desmopressin
  • Ethacrynic acid.
  • Eucalyptus.
  • Furosemide.
  • Hydrochlorothiazide.
  • Indapamide.
  • Meticlothiazide.
  • Metolazone.
  • Jugo de noni.
  • Wise.
  • Torsemide

What are the warnings and precautions for norepinephrine?

Warnings

Antidote for extravasation ischemia: To prevent shedding and necrosis in areas where extravasation has occurred, rapidly infiltrate regions with 10-15 ml of saline containing 5-10 mg of phentolamine mesylate for injection.

Use a syringe with a fine hypodermic needle, with the solution infiltrated freely over the entire area, which is easily identified by its cold, hard, and pale appearance.

This medicine contains norepinephrine. Do not take Levarterenol or Levophed if you are allergic to norepinephrine or any of the ingredients in this medicine.

Keep out of the reach of children. Get medical help or contact a Poison Control Center immediately in case of overdose.

Contraindications

  • Hypersensitivity
  • Low blood pressure (hypotension) due to a deficit in blood volume.
  • Peripheral vascular thrombosis (except for salvage procedures).
  • Concomitant use with some general anesthetics: chloroform, trichloroethylene, cyclopropane, halothane.

Precautions

  • Mesenteric or peripheral vascular thrombosis.
  • Avoid extravasation of the infusion site.
  • Not for use in profound hypoxia.
  • Sulfite allergy due to the presence of metabisulfite.
  • Monitor blood pressure.
  • Extreme caution in the concurrent use of monoamine oxidase inhibitors (MAOIs).

Pregnancy and breastfeeding

Use norepinephrine with caution during pregnancy if the benefits outweigh the risks. Animal studies show risk, and there are no human studies.

Whether norepinephrine is excreted in human milk, it is preferable to avoid use during lactation.