earth science

Promegestone

Promegestone is a earth 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 Promegestone rather than just read about it. In short: Promegestone, sold under the brand name Surgestone, is a progestin medication which is used in menopausal hormone therapy and in the treatment of gynecological disorders. It is taken by mouth.

Key takeaways

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

Reference excerpt

Promegestone, sold under the brand name Surgestone, is a progestin medication which is used in menopausal hormone therapy and in the treatment of gynecological disorders. It is taken by mouth. Side effects of promegestone include menstrual irregularities among others. Promegestone is a progestin, or a synthetic progestogen, and hence is an agonist of the progesterone receptor, the biological target of progestogens like progesterone. It has weak antiandrogenic, glucocorticoid, and antimineralocorticoid activity and no other important hormonal activity. The medication is largely a prodrug of trimegestone. Promegestone was first described in 1973 and was introduced for medical use in France in 1983. It has only been marketed in a few countries, including France, Portugal, Tunisia, and Argentina. In addition to its use as a medication, promegestone has been widely used in scientific research as a radioligand of the progesterone receptor.

Medical uses Promegestone is used in menopausal hormone therapy and in the treatment of gynecological conditions caused by luteal insufficiency, including premenopausal disorders, dysmenorrhea and other menstrual disorders, and premenstrual syndrome. It has also been used to treat benign breast disorders such as mastalgia (breast pain). Promegestone tablets have a contraceptive effect and are used as a form of progestogen-only birth control, although it is not specifically licensed as such.

Side effects

Side effects of promegestone include menstrual irregularities among others. It has no androgenic side effects.

Pharmacology

Pharmacodynamics

Promegestone is a progestogen, or an agonist of the progesterone receptor. It has about 200% of the affinity of progesterone for the PR. The endometrial transformation dosage of promegestone is 10 mg per cycle and its ovulation-inhibiting dosage is 0.5 mg/day. Promegestone has weak glucocorticoid activity in addition to its progestogenic activity. Conversely, it has no androgenic, estrogenic, mineralocorticoid, or other hormonal activity. It appears to possess antiandrogenic activity. Its major metabolite trimegestone has weak antimineralocorticoid and antiandrogenic activity. In addition, promegestone has been found to possess some neurosteroid activity by acting as a non-competitive antagonist of the nicotinic acetylcholine receptor, similarly to progesterone.

Pharmacokinetics Following oral administration, peak serum levels of promegestone are reached after 1 to 2 hours. The medication is mainly bound to albumin; it does not bind to sex hormone-binding globulin, and binds only weakly to corticosteroid-binding globulin. The metabolism of promegestone is mainly via hydroxylation at the C21 position and at other positions. Progesterone is similarly hydroxylated at the C21 position, into 11-deoxycorticosterone (21-hydroxyprogesterone). However, the C9(10) double bond of promegestone greatly limits the A-ring reduction that progesterone undergoes, resulting in 21-hydroxylation being the main route of metabolism for promegestone. The medication is stereoselectively metabolized into trimegestone, the 21(S)-hydroxy metabolite, which is the main compound found in plasma; it circulates at levels approximately twice those of promegestone itself. In addition, trimegestone has more than three-fold higher affinity for the PR than does promegestone. As such, promegestone is largely a prodrug of trimegestone. A second metabolite, 21(R)-hydroxypromegestone, circulates at far lower concentrations (AUCTooltip area-under-the-curve levels ratio for the (S)- and (R)-isomers of about 21). The elimination half-life of trimegestone is 13.8 to 15.6 hours. Promegestone, trimegestone, and 21(R)-hydroxypromegestone are not excreted in urine, while 3% of a dose is recovered as the glucuronide and/or sulfate conjugate of trimegestone and 1% of a dose is recovered as the glucuronide and/or sulfate conjugate of 21(R)-hydroxypromegestone.

Chemistry

Promegestone, also known as 17α,21-dimethyl-δ9-19-norprogesterone or as 17α,21-dimethyl-19-norpregna-4,9-diene-3,20-dione, is a synthetic norpregnane steroid and a derivative of progesterone. It is specifically a combined derivative of 17α-methylprogesterone and 19-norprogesterone, or of 17α-methyl-19-norprogesterone. Related derivatives of 17α-methyl-19-norprogesterone include demegestone and trimegestone.

History Promegestone was first described in the literature in 1973 and was introduced for medical use in France in 1983. It was developed by Roussel Uclaf in France.

Society and culture

Generic names Promegestone is the generic name of the drug and its INNTooltip International Nonproprietary Name, while promégestone is its DCFTooltip Dénomination Commune Française. It is also known by its developmental code name R-5020 or RU-5020.

Brand names Promegestone is marketed exclusively under the brand name Surgestone.

Availability Promegestone is or has been marketed in France, Portugal, Tunisia, and Argentina.

References

Illustrations

Worked examples

Example 1 — a first encounter with Promegestone

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

In research: Promegestone appears in earth 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 Promegestone 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: Promegestone is common in secondary-school and first-year university syllabi. It links to neighbouring topics Antiandrogens, Antimineralocorticoids, Conjugated dienes, so understanding it makes those chapters shorter.
In everyday life: Look for Promegestone 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 Promegestone in 20 minutes

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

Frequently asked questions

What is Promegestone in simple terms?

Promegestone, sold under the brand name Surgestone, is a progestin medication which is used in menopausal hormone therapy and in the treatment of gynecological disorders. It is taken by mouth.

Why does Promegestone matter?

Because it connects several earth 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 Promegestone?

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 Promegestone.