science

Levorphanol

Levorphanol is a science 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 Levorphanol rather than just read about it. In short: Levorphanol, sold under the brand name Levo-Dromoran, is an opioid medication used to treat moderate to severe pain. It is the levorotatory enantiomer of the compound racemorphan.

Key takeaways

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

Reference excerpt

Levorphanol, sold under the brand name Levo-Dromoran, is an opioid medication used to treat moderate to severe pain. It is the levorotatory enantiomer of the compound racemorphan. Its dextrorotatory counterpart is dextrorphan. It was first described in Germany in 1946. The drug has been in medical use in the United States since 1953.

Pharmacology Levorphanol acts predominantly as an agonist of the μ-opioid receptor (MOR), but is also an agonist of the δ-opioid receptor (DOR), κ-opioid receptor (KOR), and the nociceptin receptor (NOP), as well as an NMDA receptor antagonist and a serotonin-norepinephrine reuptake inhibitor (SNRI). Levorphanol, similarly to certain other opioids, also acts as a glycine receptor antagonist and GABA receptor antagonist at very high concentrations. As per the World Health Organization, levorphanol is a step 3 opioid and is considered eight times more potent than morphine at the MOR (2 mg levorphanol is equivalent to 15 mg morphine). Relative to morphine, levorphanol lacks complete cross-tolerance and possesses greater intrinsic activity at the MOR. The duration of action is generally long compared to other comparable analgesics and varies from 4 hours to as much as 15 hours. For this reason levorphanol is useful in palliation of chronic pain and similar conditions. Levorphanol has an oral to parenteral effectiveness ratio of 2:1, one of the most favorable of the strong narcotics. Its antagonism of the NMDA receptor, similar to those of the phenylheptylamine open-chain opioids such as methadone or the phenylpiperidine ketobemidone, make levorphanol useful for types of pain that other analgesics may not be as effective against, such as neuropathic pain. Levorphanol's exceptionally high analgesic efficacy in the treatment of neuropathic pain is also conferred by its action on serotonin and norepinephrine transporters, similar to the opioids tramadol and tapentadol, and mutually complements the analgesic effect of its NMDA receptor antagonism. Levorphanol shows a high rate of psychotomimetic side effects such as hallucinations and delirium, which have been attributed to its binding to and activation of the KOR. At the same time however, activation of this receptor as well as of the DOR have been determined to contribute to its analgesic effects.

Chemistry

Chemically, levorphanol belongs to the morphinan class and is (−)-3-hydroxy-N-methyl-morphinan. It is the "left-handed" (levorotatory) stereoisomer of racemorphan, the racemic mixture of the two stereoisomers with differing pharmacology. The "right-handed" (dextrorotatory) enantiomer of racemorphan is dextrorphan (DXO), an antitussive, potent dissociative hallucinogen (NMDA receptor antagonist), and weakly active opioid. DXO is an active metabolite of the pharmaceutical drug dextromethorphan (DXM), which, analogously to DXO, is an enantiomer of the racemic mixture racemethorphan along with levomethorphan, the latter of which has similar properties to those of levorphanol.

Society and culture

Name Levorphanol is the INN, BAN, and DCF. As the medically used tartrate salt, the drug is also known as levorphanol tartrate (USAN, BANM). The former developmental code name of levorphanol at Roche was Ro 1-5431.

Availability As the tartrate salt, levorphanol is marketed by Hikma Pharmaceuticals USA Inc. and Virtus Pharmaceuticals in the U.S., and Canada under the brand name Levo-Dromoran.

Legality Levorphanol is listed under the Single Convention On Narcotic Drugs 1961 and is regulated like morphine in most countries. In the U.S., it is a Schedule II Narcotic controlled substance with a DEA ACSCN of 9220 and 2013 annual aggregate manufacturing quota of 4.5 kilograms. The salts in use are the tartrate (free base conversion ratio 0.58) and hydrobromide (0.76).

See also Norlevorphanol Methorphan Dimemorfan Levallorphan Noscapine Codeine Pholcodine Butamirate Pentoxyverine Tipepidine Cloperastine

References

Illustrations

Worked examples

Example 1 — a first encounter with Levorphanol

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

In research: Levorphanol appears in science 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 Levorphanol 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: Levorphanol is common in secondary-school and first-year university syllabi. It links to neighbouring topics Delta-opioid receptor agonists, Drugs not assigned an ATC code, Enantiopure drugs, so understanding it makes those chapters shorter.
In everyday life: Look for Levorphanol 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 Levorphanol in 20 minutes

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

Frequently asked questions

What is Levorphanol in simple terms?

Levorphanol, sold under the brand name Levo-Dromoran, is an opioid medication used to treat moderate to severe pain. It is the levorotatory enantiomer of the compound racemorphan.

Why does Levorphanol matter?

Because it connects several science 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 Levorphanol?

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 Levorphanol.