Sandbox 45673: Difference between revisions
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==Mechanism== | ==Mechanism== | ||
Finasteride is a 5-alpha reductase inhibitor. There are two isoforms of the 5alpha-reductase enzyme, type I and II, and while the drug has a higher affinity for the type II enzyme, it also inhibits the function of the type I. ( | Finasteride is a 5-alpha reductase inhibitor. There are two isoforms of the 5alpha-reductase enzyme, type I and II, and while the drug has a higher affinity for the type II enzyme, it also inhibits the function of the type I. (Schieck,1998.) | ||
Typically 5 alpha-redcutase turns testosterone into Dihydrotestosterone(DHT), but the enzyme will accept Finasteride as an alternate substrate; turning it into dihydrofinasteride through an enzyme bound, NADP-dihydrofinasteride adduct. Finasteride is similar in structure to testosterone and 5alpha-reductase has almost the same affinity for both molecules. However, Finasteride , having a high affinity for 5 alpha-reductase, covalently binds to the enzyme as a Michael acceptor, through a functionally irreversible reaction. However, the NADP-dihydrofinasteride complex breaks down with a half life of about 1 month at 37˚C., which is why patients must continue taking the drug.(.....) | Typically 5 alpha-redcutase turns testosterone into Dihydrotestosterone(DHT), but the enzyme will accept Finasteride as an alternate substrate; turning it into dihydrofinasteride through an enzyme bound, NADP-dihydrofinasteride adduct. Finasteride is similar in structure to testosterone and 5alpha-reductase has almost the same affinity for both molecules. However, Finasteride , having a high affinity for 5 alpha-reductase, covalently binds to the enzyme as a Michael acceptor, through a functionally irreversible reaction. However, the NADP-dihydrofinasteride complex breaks down with a half life of about 1 month at 37˚C., which is why patients must continue taking the drug.(.....) | ||
http://pubs.acs.org/doi/pdf/10.1021/ja953069t | http://pubs.acs.org/doi/pdf/10.1021/ja953069t | ||