chemistry

Levofenfluramine

Levofenfluramine is a chemistry 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 Levofenfluramine rather than just read about it. In short: Levofenfluramine (INN), or (−)-3-trifluoromethyl-N-ethylamphetamine, also known as (−)-fenfluramine or (R)-fenfluramine, is a drug of the amphetamine family that, itself (i.e., in enantiopure form), was never marketed alone. It is the levorotatory enantiomer of fenfluramine, the racemic form of the compound, whereas the dextrorotatory enantiomer is dexfenfluramine.

Key takeaways

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

Reference excerpt

Levofenfluramine (INN), or (−)-3-trifluoromethyl-N-ethylamphetamine, also known as (−)-fenfluramine or (R)-fenfluramine, is a drug of the amphetamine family that, itself (i.e., in enantiopure form), was never marketed alone. It is the levorotatory enantiomer of fenfluramine, the racemic form of the compound, whereas the dextrorotatory enantiomer is dexfenfluramine. Both fenfluramine and dexfenfluramine are anorectic agents that have been used clinically in the treatment of obesity (and hence, levofenfluramine has been as well since it is a component of fenfluramine). However, they have since been discontinued due to reports of causing cardiovascular conditions such as valvular heart disease and pulmonary hypertension, adverse effects that are likely to be caused by excessive stimulation of 5-HT2B receptors expressed on heart valves. Dexfenfluramine is believed to be solely responsible for the appetite suppressant properties of fenfluramine, of which it has been demonstrated to mediate predominantly via activation of postsynaptic 5-HT1B and 5-HT2C receptors through a combination of indirect serotonin releasing agent and direct serotonin receptor agonist activities (the latter of which are mediated fully by its active metabolite dexnorfenfluramine). Contrarily, levofenfluramine is thought to contribute only to unwanted side effects. Paradoxically, however, it has been shown that levofenfluramine too acts as a relatively potent releaser of serotonin, though with approximately 1/3 of the efficacy of dexfenfluramine. As such, it would be expected to possess some degree of appetite suppressant properties as well, yet it does not. A potential explanation as to why levofenfluramine is not similarly an effective anorectic is that it has also been found to behave as a dopamine receptor antagonist, which, as dopamine antagonists like atypical antipsychotics are associated with causing increased appetite and weight gain—effects that their actions on dopamine receptors have been implicated in playing a role in the development of, is an action that could in theory cancel out the hypothetical serotonergically-mediated appetite suppressant effects of the compound. However, this is speculation and has not been proven. Levonorfenfluramine, an active metabolite of levofenfluramine, is also a fairly potent serotonin releasing agent (with a potency of approximately 1/2 that of norfenfluramine and 1/6 that of dexfenfluramine) and, similarly to dexnorfenfluramine, is a 5-HT2B and 5-HT2C receptor agonist, as well as a somewhat less potent norepinephrine reuptake inhibitor (about 1/2 that of its efficacy as a serotonin releaser). As such, it likely contributes significantly to the biological activity—though not necessarily appetite suppressant effects—of not only levofenfluramine but of racemic fenfluramine as well. In contrast to levonorfenfluramine, levofenfluramine is virtually inactive as a reuptake inhibitor or releaser of norepinephrine, and neither compound has any effect on dopamine reuptake or release. Levofenfluramine has been found to increase oxytocin levels in rodents similarly to dexfenfluramine, albeit with lower potency.

See also Fenfluramine Dexfenfluramine Norfenfluramine

References

Illustrations

Worked examples

Example 1 — a first encounter with Levofenfluramine

Start with the simplest possible case. Write down what Levofenfluramine claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, 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 Levofenfluramine 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 Levofenfluramine 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 Levofenfluramine

In research: Levofenfluramine appears in chemistry 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 Levofenfluramine 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: Levofenfluramine is common in secondary-school and first-year university syllabi. It links to neighbouring topics 3-(Trifluoromethyl)phenyl compounds, 5-HT2B agonists, Dopamine antagonists, so understanding it makes those chapters shorter.
In everyday life: Look for Levofenfluramine 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 Levofenfluramine in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Levofenfluramine 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 Levofenfluramine out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Levofenfluramine in simple terms?

Why does Levofenfluramine matter?

Because it connects several chemistry 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 Levofenfluramine?

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 Levofenfluramine.