MK-386 has been found to decrease circulating concentrations of dihydrotestosterone (DHT) in men by 20 to 30%, which is in accordance with the fact that 5α-reductase type II is responsible for 70 to 80% of DHT production while 5α-reductase type I is responsible for 20 to 30%. In contrast to MK-386, the selective 5α-reductase type II inhibitor finasteride has been found to decrease DHT levels by about 70%, while the non-selective 5α-reductase inhibitor dutasteride decreases DHT levels by up to 98%. Co-administration of MK-386 and finasteride was found to produce near-complete (~95%) suppression of circulating DHT levels.
MK-386 has been found to significantly decrease concentrations of DHT in sebum, similarly to the selective 5α-reductase type II inhibitor finasteride. However, whereas finasteride results in only a modest reduction in sebum DHT levels of 15%, MK-386 has been found to produce a significantly greater reduction of 55%. While finasteride decreases semen DHT levels by approximately 88%, MK-386 has been found to have no effect on levels of DHT in semen. These findings are in accordance with the known tissue distribution of 5α-reductase isoforms.
MK-386 was assessed in the treatment of acne but failed to separate from placebo in effectiveness and was significantly inferior to antibiotic therapy with minocycline. In addition, the addition of MK-386 to minocycline failed to increase effectiveness relative to minocycline alone. A study of MK-386 treatment for one year in stumptail macaques found that the drug failed to increase scalp hair weight in a model of androgenic alopecia, in contrast to finasteride.
References
12Bakshi RK, Patel GF, Rasmusson GH, Baginsky WF, Cimis G, Ellsworth K, etal. (November 1994). "4,7 beta-Dimethyl-4-azacholestan-3-one (MK-386) and related 4-azasteroids as selective inhibitors of human type 1 5 alpha-reductase". Journal of Medicinal Chemistry. 37 (23): 3871–3874. doi:10.1021/jm00049a003. PMID7966146.
12Ellsworth K, Azzolina B, Baginsky W, Bull H, Chang B, Cimis G, etal. (July 1996). "MK386: a potent, selective inhibitor of the human type 1 5alpha-reductase". The Journal of Steroid Biochemistry and Molecular Biology. 58 (4): 377–384. doi:10.1016/0960-0760(96)00050-7. PMID8903421. S2CID54344877.
12Leyden J, Bergfeld W, Drake L, Dunlap F, Goldman MP, Gottlieb AB, etal. (March 2004). "A systemic type I 5 alpha-reductase inhibitor is ineffective in the treatment of acne vulgaris". Journal of the American Academy of Dermatology. 50 (3): 443–447. doi:10.1016/j.jaad.2003.07.021. PMID14988688.
↑Kaufman KD (2001). "5α-Reductase Inhibitors in the Treatment of Androgenetic Alopecia". International Journal of Cosmetic Surgery and Aesthetic Dermatology. 3 (2): 107–119. doi:10.1089/153082001753231036. ISSN1530-8200.