Lesson plan
ethynerone
Ethynerone (INN, USAN), also known as 17α-(2-chloroethynyl)estra-4,9-dien-17β-ol-3-one, is a steroidal progestin of the 19-nortestosterone group that was first reported in 1961 but was never marketed. Under the developmental code name MK-665, it was studied in combination with mestranol as an oral contraceptive. Development of the drug was discontinued due to concerns surrounding toxicity findings in dogs. It is a chloroethynylated derivative of norethisterone. In 1966, during its clinical development, ethynerone was found to produce mammary gland tumors in dogs treated with it at very high doses for prolonged periods of time. Subsequent investigation found that 17α-hydroxyprogesterone derivatives included anagestone acetate, chlormadinone acetate, medroxyprogesterone acetate, and megestrol acetate produced similar mammary gland tumors, and that their ability to do so correlated directly with their progestogenic actions. In contrast, the non-halogenated 19-nortestosterone derivatives norgestrel, norethisterone, noretynodrel, and etynodiol diacetate, which are much less potent as progestogens, did not produce such effects at the dosages tested. Clinical development of ethynerone was discontinued, and many of the 17α-hydroxyprogesterone derivatives were withdrawn for the indication of hormonal contraception.…
Article summary
Ethynerone (INN, USAN), also known as 17α-(2-chloroethynyl)estra-4,9-dien-17β-ol-3-one, is a steroidal progestin of the 19-nortestosterone group that was first reported in 1961 but was never marketed. Under the developmental code name MK-665, it was studied in combination with mestranol as an oral contraceptive. Development of the drug was discontinued due to concerns surrounding toxicity findings in dogs. It is a chloroethynylated derivative of norethisterone. In 1966, during its clinical development, ethynerone was found to produce mammary gland tumors in dogs treated with it at very high doses for prolonged periods of time. Subsequent investigation found that 17α-hydroxyprogesterone derivatives included anagestone acetate, chlormadinone acetate, medroxyprogesterone acetate, and megestrol acetate produced similar mammary gland tumors, and that their ability to do so correlated directly with their progestogenic actions. In contrast, the non-halogenated 19-nortestosterone derivatives norgestrel, norethisterone, noretynodrel, and etynodiol diacetate, which are much less potent as progestogens, did not produce such effects at the dosages tested. Clinical development of ethynerone was discontinued, and many of the 17α-hydroxyprogesterone derivatives were withdrawn for the indication of hormonal contraception.…
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Discussion questions
- Summarise the article in your own words. Which single claim would you verify first, and why?
- Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
- If two sources disagreed about one of these facts, what would you need in order to trust one over the other?
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