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Isotretinoin

Isotretinoin 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 Isotretinoin rather than just read about it. In short: Isotretinoin, also known as 13-cis-retinoic acid and sold under the brand name Accutane among others, is a medication used to treat skin diseases like harlequin-type ichthyosis, lamellar ichthyosis, and severe cystic acne or moderate acne that is unresponsive to antibiotics. Isotretinoin is used off-label to treat basal cell carcinoma and squamous cell carcinoma, although clinical evidence suggests it is not effecti…

Isotretinoin — main illustration
Isotretinoin — illustration

Key takeaways

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

Reference excerpt

Isotretinoin, also known as 13-cis-retinoic acid and sold under the brand name Accutane among others, is a medication used to treat skin diseases like harlequin-type ichthyosis, lamellar ichthyosis, and severe cystic acne or moderate acne that is unresponsive to antibiotics. Isotretinoin is used off-label to treat basal cell carcinoma and squamous cell carcinoma, although clinical evidence suggests it is not effective in this setting. It is a retinoid, meaning it is related to vitamin A, and is found in small quantities naturally in the body. Its isomer, tretinoin, is also an acne drug. In its pure form, isotretinoin is an orange powder. The most common adverse effects are dry lips (cheilitis), dry and fragile skin (xeroderma), dry eyes and an increased susceptibility to sunburn. Uncommon and rare side effects include muscle aches and pains (myalgias), headaches, and depression in some users. Some of those side effects can persist long after the discontinuation of the use of the drug. Isotretinoin may cause liver failure, therefore the patient's blood levels should be regularly tested. It is known to cause birth defects due to in-utero exposure because of the molecule's close resemblance to retinoic acid, a natural vitamin A derivative that controls normal embryonic development. It is associated with psychiatric side effects, most commonly depression, and more rarely, psychosis and unusual behaviors. Other rare side effects include hyperostosis and premature epiphyseal closure, which have been reported to be persistent. Isotretinoin was patented in 1969 and approved for medical use in 1982. In 2021, it was the 264th most commonly prescribed medication in the United States, with more than 1 million prescriptions.

Medical uses Isotretinoin is used primarily for persistent cystic acne. Many dermatologists also support its use for treatment of lesser degrees of acne that prove resistant to other treatments, or that produce scarring or psychological distress. Isotretinoin is not indicated for the treatment of prepubertal acne and is not recommended in children less than 12 years of age. It is also somewhat effective for hidradenitis suppurativa and some cases of severe rosacea. It can also be used to help treat harlequin ichthyosis, lamellar ichthyosis and is used in xeroderma pigmentosum cases to relieve keratoses. Isotretinoin has been used to treat the extremely rare condition fibrodysplasia ossificans progressiva. It is also used for the treatment of pediatric neuroblastoma in Japan, but data for its efficacy is not conclusive and it has not been approved in other countries. Isotretinoin therapy has furthermore proven effective against genital warts in experimental use but is rarely used for this indication as there are more effective treatments. Isotretinoin may represent an efficacious and safe alternative systemic form of therapy for recalcitrant condylomata acuminata (RCA) of the cervix. In most countries, this therapy is currently unapproved and only used if other therapies fail.

Prescribing restrictions Isotretinoin is a teratogen; there is about a 20–35% risk for congenital defects in infants exposed to the drug in utero, and about 30–60% of children exposed to isotretinoin prenatally have been reported to show neurocognitive impairment. Because of this risk, there are strict controls prescribing isotretinoin to women who have potential to become (or be) pregnant while taking isotretinoin and many are strongly advised to terminate their pregnancies because of the 20-60% risk. Isotretinoin is also not recommended for use by breastfeeding women. In the United States, since March 2006, the dispensing of isotretinoin is run through the iPLEDGE program, under the direction of the Food and Drug Administration. Prescribers, pharmacists, and all people to whom the drug is prescribed need to register on the site and log information into it. Women with child-bearing potential must commit to using two forms of effective contraception simultaneously for the duration of isotretinoin therapy and for a month immediately preceding and a month immediately following therapy. Additionally, they must have two negative pregnancy tests 30 days apart and have negative pregnancy tests before each prescription is written. In most countries, isotretinoin can only be prescribed by dermatologists or specialist physicians; some countries also allow limited prescriptions by general practitioners and family doctors. In the United Kingdom and Australia, isotretinoin may be prescribed only by or under the supervision of a consultant dermatologist. Because severe cystic acne has the potential to cause permanent scarring over a short period, restrictions on its more immediate availability have proved contentious. In New Zealand, isotretinoin can be prescribed by any doctor but subsidized only when prescribed by a vocationally-registered general practitioner, dermatologist or nurse practitioner.

Adverse effects Increasingly higher dosages will result in higher toxicity, resembling vitamin A toxicity. Adverse effects include:

Possible permanent effects The adverse effects of isotretinoin may be permanent. This has been proposed to be due to induction of apoptosis (programmed cell death) in sebaceous glands, meibomian glands, neuroblastoma cells, hypothalamic cells, hippocampus cells, Dalton's lymphoma ascites cells, B16F-10 melanoma cells, neuronal crest cells, stem cells and others, that it changes epigenetics and shortens telomeres. Isotretinoin may stop long bone growth in young people who are still growing. Premature epiphyseal closure can occur in people receiving recommended doses of Accutane. Isotretinoin is known to cause meibomian gland dysfunction which causes persistent keratoconjunctivitis sicca (dry eye). Problems with the meibomian and salivary glands are likely due to the non-selective apoptosis of the cells of the exocrine glands. Decreased night vision has been reported to persist in some people after discontinuation of isotretinoin therapy, although most cases of decreased night vision appear to resolve after discontinuing the medication.

… excerpt ends here. Continue reading the full article.

Illustrations

Isotretinoin illustration
Isotretinoin illustration

Worked examples

Example 1 — a first encounter with Isotretinoin

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

In research
Isotretinoin 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 Isotretinoin 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
Isotretinoin is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cyclohexenes, Dermatoxins, Drugs developed by Hoffmann-La Roche, so understanding it makes those chapters shorter.
In everyday life
Look for Isotretinoin 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 Isotretinoin in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Isotretinoin means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Isotretinoin out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Isotretinoin in simple terms?

Isotretinoin, also known as 13-cis-retinoic acid and sold under the brand name Accutane among others, is a medication used to treat skin diseases like harlequin-type ichthyosis, lamellar ichthyosis, and severe cystic acne or moderate acne that is unresponsive to antibiotics. Isotretinoin is used of…

Why does Isotretinoin 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 Isotretinoin?

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 Isotretinoin.

Tags

  • Cyclohexenes
  • Dermatoxins
  • Drugs developed by Hoffmann-La Roche
  • Enones
  • Isotretinoin
  • Polyenes

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