chemistry

Tafenoquine

Tafenoquine 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 Tafenoquine rather than just read about it. In short: Tafenoquine, sold under the brand name Krintafel among others, is a medication used to prevent and to treat malaria. With respect to acute malaria, it is used together with other medications to prevent relapse by Plasmodium vivax.

Key takeaways

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

Reference excerpt

Tafenoquine, sold under the brand name Krintafel among others, is a medication used to prevent and to treat malaria. With respect to acute malaria, it is used together with other medications to prevent relapse by Plasmodium vivax. It may be used to prevent all types of malaria. It is taken by mouth. Common side effects include vomiting, headache, and dizziness. Other side effects may include methemoglobinemia, trouble sleeping, and anaphylaxis. In people with G6PD deficiency, red blood cell breakdown may occur. Use in pregnancy is not recommended. Tafenoquine is in the 8-aminoquinoline family of medications. The mechanism of action is unclear but it is effective both in the liver and bloodstream. A possible mechanism of action and other novel perspectives have been published. Tafenoquine was approved for medical use in Australia and in the United States in 2018. Tafenoquine is related to primaquine.

Medical use

Prevention Tafenoquine may be used to prevent all types of malaria. For this use 200 mg 3 days before travel then 200 mg per week until one week after travel is recommended.

Treatment Tafenoquine is used for eliminating the hypnozoite stage of Plasmodium vivax and Plasmodium ovale that is responsible for relapse of these malarial infections, even when the blood stages are successfully cleared. Primaquine for 14 days can also be used for this. The advantage of tafenoquine is that it has a long half-life (2–3 weeks) and therefore a single treatment is sufficient. For this use, a single dose of 300 mg is recommended. It is used with another medication, such as chloroquine, that kills the parasites in the bloodstream. There is a need to determine whether or not tafenoquine kills the numerous, non-circulating asexual P. vivax parasites that are now known to occur in the spleen, bone marrow, and possibly elsewhere in chronic infections.

Chemistry Tafenoquine contains a stereocenter and consists of two enantiomers. This is a mixture of (R)- and the (S)-forms:

Synthesis A chemical synthesis of tafenoquine has been reported:

p-Anisidine [104-94-9] (1) was heated in xylenes and ethyl acetoacetate to give 4'-methoxyacetoacetanilide [5437-98-9] (2). Cyclodehydration in the presence of acid led to 2-hydroxy-6-methoxy-4-methylquinoline [5342-23-4] (3). This was chlorinated with phosphorus oxychloride and sulfuryl chloride to give 2,5-dichloro-6-methoxy-4-methylquinoline [741233-61-4] (4). Methoxide addition, treatment with triethylphosphine in base, and subsequent nitration led to 5-chloro-2,6-dimethoxy-4-methyl-8-nitroquinoline [189746-21-2] (5). Ether formation between this highly activated quinoline and 3-(trifluoromethyl)phenol [98-17-9] (6) occurred under basic conditions. Next, treatment with Darco KB and hydrazine promoted nitro reduction gave 2,6-dimethoxy-4-methyl-5-[3-(trifluoromethyl)phenoxy]quinolin-8-amine [106635-86-3] (7). Alkylation with 4-iodo-1-phthalimido-pentane [63460-47-9] (8) incorporated the sidechain to give [106635-87-4 ] (9). Wolff-Kishner reduction of the phthalimide to the primary amine completed the synthesis of tafenoquine (10).

History Tafenoquine was approved for medical use in Australia and in the United States in 2018. Tafenoquine was given an orphan drug designation and was granted breakthrough therapy status in 2013 in the United States.

Society and culture One version is made by GlaxoSmithKline, while another is made by 60 Degrees Pharmaceutical.

Names Etaquine was a generic name proposed by WRAIR, and subsequently rejected by CDER. Trade names

Kozenis (Australia) Kodatef (Australia) Arakoda (USA), Krintafel (USA)

References

External links "Tafenoquine". Drug Information Portal. U.S. National Library of Medicine. Archived from the original on 7 August 2020.

Illustrations

Worked examples

Example 1 — a first encounter with Tafenoquine

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

In research: Tafenoquine 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 Tafenoquine 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: Tafenoquine is common in secondary-school and first-year university syllabi. It links to neighbouring topics 3-(Trifluoromethyl)phenyl compounds, Antimalarial agents, Diaryl ethers, so understanding it makes those chapters shorter.
In everyday life: Look for Tafenoquine 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 Tafenoquine in 20 minutes

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

Frequently asked questions

What is Tafenoquine in simple terms?

Why does Tafenoquine 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 Tafenoquine?

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 Tafenoquine.