biology

Norepinephrine (medication)

Norepinephrine (medication) is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Norepinephrine (medication) rather than just read about it. In short: Norepinephrine, also known as noradrenaline and sold under the brand name Levophed among others, is a medication used to treat people with very low blood pressure. It is the typical medication used in sepsis if low blood pressure does not improve following intravenous fluids.

Key takeaways

Norepinephrine (medication) belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Norepinephrine (medication) to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Norepinephrine (medication) from memory before moving on to harder problems.

Reference excerpt

Norepinephrine, also known as noradrenaline and sold under the brand name Levophed among others, is a medication used to treat people with very low blood pressure. It is the typical medication used in sepsis if low blood pressure does not improve following intravenous fluids. It is the same molecule as the hormone and neurotransmitter norepinephrine. It is given by slow injection into a vein. Common side effects include headache, slow heart rate, and anxiety. Other side effects include an irregular heartbeat. If it leaks out of the vein at the site it is being given, norepinephrine can result in limb ischemia. If leakage occurs the use of phentolamine in the area affected may improve outcomes. Norepinephrine works by binding and activating alpha adrenergic receptors. Norepinephrine was discovered in 1946 and was approved for medical use in the United States in 1950. It is available as a generic medication.

Medical uses Norepinephrine is used mainly as a sympathomimetic drug to treat people in vasodilatory shock states such as septic shock and neurogenic shock, while showing fewer adverse side-effects compared to dopamine treatment.

Pharmacology

Mechanism of action It stimulates α1 and α2 adrenergic receptors to cause blood vessel contraction, thus increases peripheral vascular resistance and resulted in increased blood pressure. This effect also reduces the blood supply to gastrointestinal tract and kidneys. Norepinephrine acts on beta-1 adrenergic receptors, causing increase in heart rate and cardiac output. However, the elevation in heart rate is only transient, as baroreceptor response to the rise in blood pressure as well as enhanced vagal tone ultimately result in a sustained decrease in heart rate. Norepinephrine acts more on alpha receptors than the beta receptors.

Pharmacokinetics Norepinephrine does not cross the blood–brain barrier under normal circumstances and hence is a peripherally selective drug.

Chemistry Norepinephrine, or noradrenaline, also known as 3,4,β-trihydroxyphenethylamine, is a substituted phenethylamine and catecholamine. It is the N-demethylated analogue of epinephrine (adrenaline; 3,4,β-trihydroxy-N-methylphenethylamine) and the β-hydroxylated analogue of dopamine (3,4-dihydroxyphenethylamine).

Society and culture

Names Norepinephrine is the generic name of the drug and its INNTooltip International Nonproprietary Name, while noradrenaline is its BANTooltip British Approved Name. It is often referred to as simply "levo" in clinical settings in the United States, an abbreviation of the trade name Levophed.

References

External links "Norepinephrine". Drug Information Portal. U.S. National Library of Medicine. Archived from the original on February 12, 2017. "Norepinephrine bitartrate". Drug Information Portal. U.S. National Library of Medicine. Archived from the original on October 22, 2020.

Illustrations

Worked examples

Example 1 — a first encounter with Norepinephrine (medication)

Start with the simplest possible case. Write down what Norepinephrine (medication) claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Norepinephrine (medication) before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Norepinephrine (medication) ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Norepinephrine (medication)

In research: Norepinephrine (medication) appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Norepinephrine (medication) in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Norepinephrine (medication) is common in secondary-school and first-year university syllabi. It links to neighbouring topics Antihypotensive agents, Cardiac stimulants, Inotropic agents, so understanding it makes those chapters shorter.
In everyday life: Look for Norepinephrine (medication) outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Norepinephrine (medication) in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Norepinephrine (medication) means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Norepinephrine (medication) out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Norepinephrine (medication) in simple terms?

Why does Norepinephrine (medication) matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Norepinephrine (medication)?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Norepinephrine (medication).