norepinephrine

Action and Spectrum

Actions and Spectrum 

norepinephrine is the naturally-found catecholamine that is also an important neurotransmitter in the sympathetic nervous system. It functions as a vasoconstrictor in the case that it makes the blood vessels narrow hence the blood pressure and cardiac output are increased. It also favours the release of glucose from energy stores e.g. the liver and adipose tissue, hence enhanced blood sugar levels. It has a pharmacological application as a vasopressor agent to raise blood pressure and maintain organ perfusion in cases of hypotension, sepsis and shock. 

Drug Interaction

Adverse Reaction

Frequency not defined 

Bradycardia 

Arrhythmias 

Anxiety 

Headache 

Sweating 

Restlessness 

Extravasation 

Hypertension 

Confusion 

Dyspnea 

Nausea and vomiting 

Tremor 

Urinary retention 

Gangrene 

Black Box Warning

Black Box Warning 

norepinephrine has a Black Box Warning for its potential to cause severe hypertension (high blood pressure) that can lead to cerebral hemorrhage (bleeding in the brain) or pulmonary edema (fluid buildup in the lungs). This is especially a concern for patients with pre-existing hypertension or cardiac disease.

Contraindication / Caution

Contraindication/Caution: 

Contraindication: 

norepinephrine is contraindicated in patients with hypotension caused by hypovolemia or dehydration. It should also be avoided in patients with mesenteric or peripheral vascular thrombosis or thromboembolism, in patients with hypoxia, hypercapnia, acidosis, or other severe metabolic acidosis, and in patients with narrow-angle glaucoma.  

Caution: 

• Hypovolemia or dehydration 
• Cardiac disease 
• Hypertension 
• Diabetes 
• Hyperthyroidism 

Pregnancy / Lactation

Pregnancy/Lactation 

Pregnancy consideration: US FDA pregnancy category: C 

Lactation: It is also not known if norepinephrine passes into breast milk 

Pregnancy category: 

• Category A: Satisfactory and well-controlled studies show no risk to the fetus in the first or later trimester. 
• Category B: There is no evidence of risk to the fetus found in animal reproduction studies and there are not enough studies on pregnant women. 
• Category C: Adverse effects on the fetus found with evidence in animal reproduction studies and no adequate evidence for an effect in humans, care must be taken for potential risks in pregnant women. 
• Category D: There is adequate data available with sufficient evidence of human fetal risk from various platforms, but despite potential risks may be used only in emergency cases for potential benefits. 
• Category X: Drugs listed in this category outweigh risks over benefits These category drugs should be prohibited for pregnant women. 
• Category N: There is no data available for the drug under this category. 

Pharmacology

Pharmacology 

noradrenaline is a naturally occurring catecholamine and a neurotransmitter that acts on both alpha- and beta-adrenergic receptors. It originates in the adrenal medulla and is released then in the blood after being excited by a stress or an activation of the sympathetic nervous system system. In the pharmaceutical application, norepinephrine acts as a powerful vasoconstrictor, causing the blood pressure and the cardiac output to increase respectively. norepinephrine activates both alpha-1 and alpha-2 adrenergic receptors in the peripheral vasculature, leading to vasoconstriction and rise in peripheral resistance. 

Pharmacodynamics: 

norepinephrine is a naturally occurring catecholamine neurotransmitter and hormone which binds to α1-adrenergic, α2-adrenergic, and β1-adrenergic receptor groups at a high potency. It mainly has pharmacodynamic effect at any activity that causes contraction of peripheral blood vessels and increases the systemic vascular resistance. noradrenaline also causes the cardiac output and the heart rate to increase by means of β1-adrenergic receptor stimulation in the heart. At higher doses, it is also a β2-adrenergic receptor stimulator and leads to vasodilation in some vascular beds such as the skeletal muscle and liver by this way of action. The net effect of the norepinephrine on blood pressure and cardiac output results from the dose and the balance between the α-adrenergic and β-adrenergic effects. 

Pharmacokinetics: 

Absorption
It is absorbed throughout the body and the duration of action is not known 

Distribution 

It is highly protein-bound (to albumin) and not much of it crosses the blood-brain barrier in significant quantities. The drug has a volume of distribution of around 2. 6 L/kg. 

Metabolism 

It is primarily metabolized by monoamine oxidase (MAO) in the liver and other tissues. The norepinephrine catabolites include vanillylmandelic acid (VMA) and 3-methoxy-4-hydroxyphenyl glycol (MHPG). 

Elimination and excretion 

The elimination half-life of norepinephrine is 2 minutes, and is mostly cleared through uptake-1 reuptake into sympathetic nerve endings, where it is metabolized by MAO or stored in vesicles. 

Adminstartion

Administration 

It is administered as an intravenous infusion 

Patient Information Leaflet

Patient information leaflet 

Generic Name: norepinephrine 

Pronounced: [ nor-ep-i-NEF-rin ] 

Why do we use norepinephrine? 

Norepinephrine is like adrenaline which is used as a medication in the case of severe hypotension (low blood pressure) during illnesses or surgeries. It is normally involved in cardio-pulmonary resuscitation (CPR) cases.