science

Tipiracil

Tipiracil 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 Tipiracil rather than just read about it. In short: Tipiracil is a drug used in the treatment of cancer. It is approved for use in form of the combination drug trifluridine/tipiracil for the treatment of unresectable advanced or recurrent colorectal cancer.

Key takeaways

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

Reference excerpt

Tipiracil is a drug used in the treatment of cancer. It is approved for use in form of the combination drug trifluridine/tipiracil for the treatment of unresectable advanced or recurrent colorectal cancer. Tipiracil helps maintain the blood concentration of trifluridine by inhibiting the enzyme thymidine phosphorylase which metabolizes trifluridine.

Adverse effects Adverse effects were not assessed independently of trifluridine, but only in the combination drug.

Interactions Only in vitro interaction studies are available. In these, tipiracil was transported by the solute carrier proteins SLC22A2 and SLC47A1. Drugs that interact with these transporters could influence blood plasma concentrations of tipiracil.

Pharmacology

Mechanism of action

Tipiracil is a thymidine phosphorylase (TPase) inhibitor and inhibits degradation of trifluridine by inhibiting TPase, thus increasing systemic exposure to trifluridine when tipiracil is given together with trifluridine.

Pharmacokinetics At least 27% of tipiracil is absorbed from the gut. In cancer patients, highest blood plasma concentrations are reached after three hours. The substance has no tendency to accumulate in the body. The in vitro protein binding in human plasma is below 8%. Tipiracil is not metabolized by cytochrome P450 (CYP) enzymes. To a small extent, it is hydrolyzed to 6-hydroxymethyluracil, but the main fraction is excreted in unchanged form in the faeces (50%) and urine (27%). Elimination half-life is 2.1 hours on the first day and then slightly increases to 2.4 hours on the twelfth day. Tipiracil causes Cmax (highest blood plasma concentrations) of trifluridine to increase 22-fold, and its area under the curve 37-fold.

Chemistry Tipiracil is used in form of the hydrochloride, which is a white crystalline powder. Solubility in water is 5 mg/mL; it is also soluble in 0.01 M hydrochloric acid and 0.01 M sodium hydroxide; slightly soluble in methanol; very slightly soluble in ethanol; and practically insoluble in acetonitrile, isopropyl alcohol, acetone, diisopropyl ether, and diethyl ether.

COVID-19 Tipiracil has been shown to inhibit SARS-CoV-2 Nsp15 and interacts with the uridine binding pocket of the enzyme's active site using a combination of crystallography, biochemical and whole cell assays. It had previously been suggested in a computational drug repurposing study as the most promising hit targeting the main SARS-CoV-2 protease.

References

Illustrations

Worked examples

Example 1 — a first encounter with Tipiracil

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

In research: Tipiracil 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 Tipiracil 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: Tipiracil is common in secondary-school and first-year university syllabi. It links to neighbouring topics COVID-19 drug development, Enzyme inhibitors, Organochlorides, so understanding it makes those chapters shorter.
In everyday life: Look for Tipiracil 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 Tipiracil in 20 minutes

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

Frequently asked questions

What is Tipiracil in simple terms?

Why does Tipiracil 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 Tipiracil?

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 Tipiracil.