chemistry

Lopinavir

Lopinavir 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 Lopinavir rather than just read about it. In short: Lopinavir is an antiretroviral of the protease inhibitor class. It is used against HIV infections as a fixed-dose combination with another protease inhibitor, ritonavir (lopinavir/ritonavir).

Key takeaways

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

Reference excerpt

Lopinavir is an antiretroviral of the protease inhibitor class. It is used against HIV infections as a fixed-dose combination with another protease inhibitor, ritonavir (lopinavir/ritonavir). It was patented in 1995 and approved for medical use in 2000. Considered now as second-line therapy in the West, it is still prescribed in LMIC, especially among children living with HIV. Lopinavir and ritonavir can be taken as a tablet or an oral solution, a preferred option in children. In the early stages of COVID-19 pandemics, lopinavir was repurposed against the SARS-CoV-2 virus in the hope of disturbing its protease activity.

Side effects Side effects, interactions, and contraindications have only been evaluated in the drug combination lopinavir/ritonavir. They include nausea, vomiting, and stomach aches.

Pharmacology Lopinavir is highly bound to plasma proteins (98–99%). Reports are contradictory regarding lopinavir penetration into the cerebrospinal fluid (CSF). Anecdotal reports state that lopinavir cannot be detected in the CSF; however, a study of paired CSF-plasma samples from 26 patients receiving lopinavir/ritonavir found lopinavir CSF levels above the IC50 in 77% of samples.

Research A 2014 study indicates that lopinavir is effective against the human papilloma virus (HPV). The study used the equivalent of one tablet twice a day applied topically to the cervices of women with high-grade and low-grade precancerous conditions. After three months of treatment, 82.6% of the women who had high-grade disease had normal cervical conditions, confirmed by smears and biopsies. Lopinavir has been shown to impair protein synthesis via AMP-activated protein kinase (AMPK) and eEF2 kinase (eEF2K) activation, a mechanism that is similar to the antiviral effect of protein phosphatase 1 inhibitors. Lopinavir was found to inhibit MERS-CoV replication in the low-micromolar range in cell cultures. In 2020, lopinavir/ritonavir was found not to work in severe COVID-19. In this trial the medication was started typically around 13 days after the start of symptoms.

Synthesis A couple of Lopinavir syntheses were reported: Below is one of them.

L-Valine [72-18-4] (1) gives N-Phenoxycarbonyl-L-valine [126147-70-4] ('2). Treatment with 3-Chloropropylamine [14753-26-5] (3) gives (S)-3-methyl-2-(2-oxotetrahydropyrimidine-1-yl)butyric acid [192725-50-1] (4). Halogenation with thionyl chloride leads to (2S)-3-Methyl-2-(2-oxotetrahydropyrimidin-1(2H)-yl)butanoyl chloride [192800-77-4] (5). Reaction with (2S,3S,5S)-5-Amino-2-dibenzylamino-1,6-diphenyl-3-hydroxyhexane, PC9890651 (6) yields (S)-N-[(2S,4S,5S)-5-(Dibenzylamino)-4-hydroxy-1,6-diphenylhexan-2-YL]-3-methyl-2-(2-oxotetrahydropyrimidin-1(2H)-YL)butanamide [192726-04-8] (7). The catalytic hydrogenation removes the protecting group to give (2S)-N-[(2S,4S,5S)-5-amino-4-hydroxy-1,6-diphenylhexan-2-yl]-3-methyl-2-(2-oxo-1,3-diazinan-1-yl)butanamide [192726-05-9] (8). Amide formation with (2,6-Dimethylphenoxy)acetyl Chloride [20143-48-0] (9) completes the synthesis of lopinavir (10).

References

Illustrations

Worked examples

Example 1 — a first encounter with Lopinavir

Start with the simplest possible case. Write down what Lopinavir 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 Lopinavir 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 Lopinavir 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 Lopinavir

In research: Lopinavir 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 Lopinavir 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: Lopinavir is common in secondary-school and first-year university syllabi. It links to neighbouring topics CYP3A4 inhibitors, Drugs developed by AbbVie, HIV protease inhibitors, so understanding it makes those chapters shorter.
In everyday life: Look for Lopinavir 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 Lopinavir in 20 minutes

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

Frequently asked questions

What is Lopinavir in simple terms?

Lopinavir is an antiretroviral of the protease inhibitor class. It is used against HIV infections as a fixed-dose combination with another protease inhibitor, ritonavir (lopinavir/ritonavir).

Why does Lopinavir 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 Lopinavir?

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 Lopinavir.