Results for norepinephrine
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Dictionary:

norepinephrine

  (nôr'ĕp-ə-nĕf'rĭn) pronunciation
n.

A substance, C8H11NO3, both a hormone and neurotransmitter, secreted by the adrenal medulla and the nerve endings of the sympathetic nervous system to cause vasoconstriction and increases in heart rate, blood pressure, and the sugar level of the blood. Also called noradrenaline.


 
 
Dental Dictionary: norepinephrine
(nôr′epinef′rin)
n

The neurohormonal transmitter for neuroeffector junctions of adrenergic nerve fibers. Its official drug name in the United States is levarterenol. See also levarterenol.

 
Drug Info: Norepinephrine

Brand names: Levophed®



Norepinephrine injection

What is norepinephrine injection?

NOREPINEPHRINE (Levophed®) treats a number of serious heart problems including very low blood pressure. Generic norepinephrine injections are available.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of the following conditions:
• high blood pressure
• over active thyroid
• thrombosis
• an unusual or allergic reaction to norepinephrine, sulfites, other medicines, foods, dyes, or preservatives
• pregnant or trying to get pregnant
• breast-feeding

How should I use this medicine?

Norepinephrine is for infusion into a vein. It is given by a health-care professional in a hospital or clinic setting.

What if I miss a dose?

This does not apply.

What drug(s) may interact with norepinephrine?

• atropine
• bretylium
• bromocriptine
• entacapone
• linezolid
• maprotiline
• medicines for mental depression
• medicines for migraine
• medicine for high blood pressure
• oxytocin
• tolcapone
• vasopressin
• water pills

Tell your prescriber or health care professional about all other medicines you are taking, including non-prescription medicines, nutritional supplements, or herbal products. Also tell your prescriber or health care professional if you are a frequent user of drinks with caffeine or alcohol, if you smoke, or if you use illegal drugs. These may affect the way your medicine works. Check before starting or stopping any of your medicines.

What should I watch for while taking norepinephrine?

Your condition will be closely monitored during use of norepinephrine.

If you are diabetic norepinephrine may increase your blood sugar. Check your blood or urine sugar often and contact your prescriber or health care professional if you have any problems.

Do not use a norepinephrine solution that appears cloudy, pinkish, brownish, or has a precipitate.

What side effects may I notice from receiving norepinephrine?

Side effects that you should report to your prescriber or health care professional as soon as possible:
• difficulty breathing, wheezing
• dizziness or fainting spells
• irregular heartbeat, palpitations, or chest pain
• pain, redness, swelling or irritation at the injection site
• skin rash, hives

Side effects that usually do not require medical attention (report to your prescriber or health care professional if they continue or are bothersome):
• anxiety or nervousness
• difficulty sleeping
• headache
• increased sweating
• nausea, vomiting
• weakness or tiredness

Where can I keep my medicine?

Keep out of the reach of children.

Store at room temperature between 15—30 degrees C (59—86 degrees F). Protect from light. Throw away any unused portion. Do not use if solution is discolored or particles are present. Throw away any unused medicine after the expiration date.


Last updated: 7/1/2002

Important Disclaimer: The drug information provided here is for educational purposes only. It is intended to supplement, not substitute for, the diagnosis, treatment and advice of a medical professional. This drug information does not cover all possible uses, precautions, side effects and interactions. It should not be construed to indicate that this or any drug is safe for you. Consult your medical professional for guidance before using any prescription or over the counter drugs.

 

One of two catecholamine hormones (epinephrine is the other) secreted by the adrenal glands, as well as at nerve endings, as a neurotransmitter. It resembles adrenaline chemically and in its actions on the body, which mimic sympathetic nervous system stimulation. It constricts most blood vessels and is given for certain types of shock. Norepinephrine is formed from tyrosine and converted to epinephrine. It was discovered by Ulf von Euler-Chelpin (1905 – 83) in the mid-1940s.

For more information on norepinephrine, visit Britannica.com.

 
Columbia Encyclopedia: norepinephrine
(nôr'ĕpīnĕf'rən) , a neurotransmitter in the catecholamine family that mediates chemical communication in the sympathetic nervous system, a branch of the autonomic nervous system. Like other neurotransmitters, it is released at synaptic nerve endings to transmit the signal from a nerve cell to other cells. Norepinephrine is almost identical in structure to epinephrine, which is released into the bloodstream from the adrenal medulla under sympathetic activation. The sympathetic nervous system functions in response to short-term stress; hence norepinephrine and epinephrine increase the heart rate as well as blood pressure. Other actions of norepinephrine include increased glycogenolysis (the conversion of glycogen to glucose) in the liver, increased lipolysis (the conversion of fats to fatty acids; see fats and oils) in adipose (fat) tissue, and relaxation of bronchial smooth muscle to open up the air passages to the lungs. All of these actions represent a mobilization of the body's resources in order to meet the stressful challenge—such a response is often termed the “flight or fight” syndrome.


 
Veterinary Dictionary: norepinephrine

A catecholamine which is the neurotransmitter of most sympathetic postganglionic neurons and also of certain tracts in the central nervous system. It is also a neurohormone stored in the chromaffin granules of the adrenal medulla and released in response to sympathetic stimulation, primarily in response to hypotension. It produces vasoconstriction, an increase in heart rate, and elevation of blood pressure. It is used as a vasopressor, administered by intravenous infusion, to restore blood pressure in certain cases of acute hypotension and as an adjunct in the treatment of cardiac arrest. Called also norepinephrine.


 
Wikipedia: norepinephrine
Norepinephrine[1]
Chemical structure of norepinephrine
Norepinephrine-3d-CPK.png
Chemical name 4-(2-Amino-1-hydroxyethyl)
benzene-1,2-diol
Other names Noradrenaline
Chemical formula C8H11NO3
Molecular mass 169.18 g/mol
CAS number D: [149-95-1]
L: [51-41-2]
D/L: [138-65-8]
Melting point L: 216.5-218 °C (decomp.)
D/L: 191 °C (decomp.)
SMILES NC[C@H](O)c1ccc(O)c(O)c1
Disclaimer and references

Norepinephrine (INN)(abbr. norepi or NE) or noradrenaline (BAN) is a catecholamine and a phenethylamine with chemical formula C8H11NO3. The natural stereoisomer is L-(−)-(R)-norepinephrine. The prefix nor-, short for "normal," might also now be a mnemonic device for the German abbreviation "N (symbol for nitrogen) ohne Radikalen," meaning "Nitrogen without remainder," referring to the absence of a methyl group at the N-atom present in epinephrine/adrenaline. It is released from the adrenal medulla of the adrenal glands as a hormone into the blood, but it is also a neurotransmitter in the central nervous system and sympathetic nervous system where it is released from noradrenergic neurons during synaptic transmission. As a stress hormone, it affects parts of the human brain where attention and responding actions are controlled. Along with epinephrine, norepinephrine underlies the fight-or-flight response, directly increasing heart rate, triggering the release of glucose from energy stores, and increasing skeletal muscle readiness.

However, when norepinephrine acts as a drug, it will increase systolic and diastolic pressure, causing compensatory vagal reflex, which overcomes its direct cardioaccelerator action. Therefore, it will cause reflex bradycardia in patient.

Norepinephrine is released when a host of physiological changes are activated by a stressful event. This is caused in part by activation of an area of the brain stem called the locus ceruleus. This nucleus is the origin of most norepinephrine pathways in the brain. Neurons that are activated by norepinephrine project bilaterally (send signals to both sides of the brain) from the locus ceruleus along distinct pathways to many locations, including the cerebral cortex, limbic system, and the spinal cord. The locus ceruleus (or "LC") is located within the dorsal wall of the rostral pons in the lateral floor of the fourth ventricle (see picture).

At synapses, norepinephrine acts on both alpha and beta adrenoreceptors.

Natural Production

Norepinephrine is naturally released both in the central nervous system where it helps control alertness and arousal, and from peripheral sympathetic nerves where it exerts diverse effects on its target organs. It is synthesized from dopamine by dopamine-B-oxidase.[2]

Clinical uses

Attention-deficit/hyperactivity disorder

Norepinephrine, along with dopamine, has come to be recognized as playing a large role in attention and focus. For people with ADD/ADHD, psychostimulant medications such as Ritalin/Concerta (methylphenidate), Dexedrine (dextroamphetamine), and Adderall (a mixture of dextroamphetamine and racemic amphetamine salts) are prescribed to help increase levels of norepinephrine and dopamine. Strattera (atomoxetine) is a selective norepinephrine reuptake inhibitor, and is a unique ADD/ADHD medication, as it affects only norepinephrine, rather than dopamine. As a result, Strattera has a lower abuse potential. However, it may not be as effective as the psychostimulants are with many people who have ADD/ADHD. Consulting with a physician or nurse practitioner is needed to find the appropriate medication and dosage. (Other SNRIs, currently approved as antidepressants, have also been used off-label for treatment of ADD/ADHD.)

Depression

Differences in the norepinephrine system are implicated in depression. Serotonin-norepinephrine reuptake inhibitors are antidepressants that treat depression by increasing the amount of serotonin and norepinephrine available to postsynaptic cells in the brain. There is some recent evidence, implying that SNRIs may also increase dopamine transmission.[citation needed] This is because SNRIs work by inhibiting reuptake, i.e. preventing the serotonin and norepinephrine transporters from taking their respective neurotransmitters back to their storage vesicles for later use. If the norepinephrine transporter normally recycles some dopamine too, then SNRIs will also enhance dopaminergic transmission. Therefore, the antidepressant effects associated with increasing norepinephrine levels may also be partly or largely due to the concurrent increase in dopamine (particularly in the prefrontal cortex).

Tricyclic antidepressants (TCAs) increase norepinephrine activity as well. Most of them also increase serotonin activity, but tend to have side effects due to the nonspecific activation of histamine and acetylcholine receptors. Side effects include tiredness, increased hunger, dry mouth, and blurred vision. For this reason, they have largely been replaced by newer selective reuptake drugs such as Prozac.

Vasoconstriction

Norepinephrine is also used as a vasopressor medication (for example, brand name Levophed) for patients with critical hypotension. It is given intravenously and acts on both alpha-1 and alpha-2 adrenergic receptors to cause vasoconstriction. Its effect in vitro is often limited to the increasing of blood pressure through agonistic activity on alpha-1 and alpha-2 receptors and causing a resultant increase in peripheral vascular resistance. In high dose and especially when it is combined with other vasopressors, it can lead to limb ischemia and limb death. Norepinephrine is mainly used to treat patients in vasodilatory shock states such as septic shock and neurogenic shock and has shown a survival benefit over dopamine.

Biosynthesis

Norepinephrine is synthesized by a series of enzymatic steps in the adrenal medulla from the amino acid tyrosine:

Metabolites

In mammals, norepinephrine is rapidly degraded to various metabolites. The principal metabolites are:

  • Normetanephrine (via the enzyme catechol-O-methyl transferase, COMT)
  • 3,4-Dihydroxymandelic acid (via monoamine oxidase, MAO)
  • 3-Methoxy-4-hydroxymandelic acid (via MAO)
  • 3-Methoxy-4-hydroxyphenylglycol (via MAO)
  • Epinephrine (via PNMT[1])

References

Brunton, Lazo, Parker: Goodmn &Gilman's The Pharmacological Basis of Therapeutics. McGraw Hill, 11th edition. p248~249

  1. ^ "Endokrynologia Kliniczna" ISBN 83-200-0815-8, page 502

External links



 
 

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Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2007. Published by Houghton Mifflin Company. All rights reserved.  Read more
Dental Dictionary. Mosby's Dental Dictionary. Copyright © 2004 by Elsevier, Inc. All rights reserved.  Read more
Drug Info. Gold Standard. Copyright © 2008 by Gold Standard. All rights reserved.  Read more
Britannica Concise Encyclopedia. Britannica Concise Encyclopedia. © 2006 Encyclopædia Britannica, Inc. All rights reserved.  Read more
Columbia Encyclopedia. The Columbia Electronic Encyclopedia, Sixth Edition Copyright © 2003, Columbia University Press. Licensed from Columbia University Press. All rights reserved. www.cc.columbia.edu/cu/cup/  Read more
Veterinary Dictionary. The Veterinary Dictionary. Copyright © 2007 by Elsevier. All rights reserved.  Read more
Wikipedia. This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Norepinephrine" Read more

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