MK-386 has been found to decrease circulating concentrations of dihydrotestosterone (DHT) in men by 20 to 30%,[5] 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%.[6] 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%.[7] Co-administration of MK-386 and finasteride was found to produce near-complete (~95%) suppression of circulating DHT levels.[8]
MK-386 has been found to significantly decrease concentrations of DHT in sebum, similarly to the selective 5α-reductase type II inhibitor finasteride.[9] 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%.[9] While finasteride decreases semen DHT levels by approximately 88%, MK-386 has been found to have no effect on levels of DHT in semen.[9] These findings are in accordance with the known tissue distribution of 5α-reductase isoforms.[10]
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.[11][12] In addition, the addition of MK-386 to minocycline failed to increase effectiveness relative to minocycline alone.[11][12] 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.[13][14]
References
^ abBakshi RK, Patel GF, Rasmusson GH, Baginsky WF, Cimis G, Ellsworth K, et al. (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.
^ abEllsworth K, Azzolina B, Baginsky W, Bull H, Chang B, Cimis G, et al. (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.
^ abLeyden J, Bergfeld W, Drake L, Dunlap F, Goldman MP, Gottlieb AB, et al. (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.