Objective: The development of the human benign prostatic hyperplasia clearly requires a combination of testicular androgens and aging. Although the role of androgens as the causative factor for human benign prostatic hyperplasia is debated, they undoubtedly have at least a permissive role. The principal prostatic androgen is dihydrotestosterone (DHT). Although not elevated in human benign prostatic hyperplasia, DHT levels in the prostate remain at a normal level with aging, despite a decrease in the plasma testosterone.Results: DHT is generated by reduction of testosterone. Two isoenzymes of 5α–reductase have been discovered. Type 1 is present in most tissues of the body where 5α–reductase is expressed and is the dominant form in sebaceous glands. Type2 5α–reductase is the dominant isoenzyme in genital tissues, including the prostate. Finasteride is a 5α–reductase inhibitor that has been used for the treatment of benign prostatic hyperplasia and male–pattern baldness. At doses used clinically, its major effect is through suppression of type 2 5α–reductase, because it has a much lower affinity for the type 1 isoenzyme. Finasteride suppresses DHT by about 70% in serum and by as much as 85–90% in the prostate. The remaining DHT in the prostate is likely to be the result of type 1 5α–reductase. Suppression of both 5α–reductase isoenzymes with GI198745 result in greater and more consistent suppression of serum dihydrotestosterone than that observed with a selective inhibitor of type 2 5α–reductase. Physiological and clinical studies comparing dual 5α–reductase inhibitors, such as GI198745, with selective type 2, such as finasteride, will be needed to determine the clinical relevance of type 1 5α–reductase within the prostate. Two large international multicenter, phase III trials have been published documenting the safety and efficacy of finasteride in the treatment of human benign prostatic hyperplasia. Combining these two studies, randomized, controlled data are available for 12 months. Noncontrolled extension of these data from a subset of patients, who elected to continue drug treatment for 3, 4 or 5 years, are also available. Long–term medical therapy with finasteride can reduce clinically significant endpoints such as acute urinary retention or surgery. According to the meta–analysis of six randomised clinical trial with finasteride, finasteride is most effective in men with large prostates. A more effective dual inhibitor of type 1 and 2 human 5α–reductase may lower circulating DHT to a greater extent than finasteride and show advantages in the treatment of human benign prostatic hyperplasia and other disease states that depend on DHT.Conclusion: Clinical evaluation of potent dual 5α–reductase inhibitors may help define the relative roles of human type 1 and 2 5α–reductase in the pathophysiology of benign prostatic hyperplasia and other androgen–dependent diseases.

Coffey D, Berry S, Ewing L: An overview of current concepts in the study of benign prostatic hyperplasia; in Rodgers C, et al (eds): Benign Prostatic Hyperplasia. Bethesda, National Institutes of Health, 1987, vol 2.
Walsh P: Benign prostatic hyperplasia; in Walsh P, Gittes R, Perlmutter A, Stamey T (eds): Campbells’ Urology. Baltimore, Saunders, 1985, vol 2.
Wilson JD: The pathogenesis of benign prostatic hyperplasia. Am J Med 1980;68:745– 756.
Walsh PC, Hutchins GM, Ewing LL: Tissue content of dihydrotestosterone in human prostatic hyperplasia is not supranormal. J Clin Invest 1983;72:1772–1777.
Cowan RA, Cowan SK, Grant JK, Elder HY: Biochemical investigations of separated epithelium and stroma from benign hyperplastic prostatic tissue. J Endocrinol 1977;74:111– 120.
Silver RI, Wiley EL, Davis DL, Thigpen AE, Russell DW, McConnell JD: Expression and regulation of steroid 5 alpha–reductase 2 in prostate disease. J Urol 1994;152:433–437.
Silver RI, Wiley EL, Thigpen AE, Guileyardo JM, McConnell JD, Russell DW: Cell type specific expression of steroid 5 alpha–reductase 2. J Urol 1994;152:438–442.
Jenkins EP, Andersson S, Imperato–McGinley J, Wilson JD, Russell DW: Genetic and pharmacological evidence for more than one human steroid 5 alpha–reductase. J Clin Invest 1992;89:293–300.
Martini L, Zoppi S, Motta M: Studies on the possible existence of two 5 alpha–reductases in the rat prostate. J Steroid Biochem 1986;24: 177–182.
Moore RJ, Wilson JD: Steroid 5 alpha–reductase in cultured human fibroblasts. Biochemical and genetic evidence for two distinct enzyme activities. J Biol Chem 1976;251:5895– 5900.
Russell DW, Wilson JD: Steroid 5 alpha–reductase: Two genes/two enzymes. Annu Rev Biochem 1994;63:25–61.
Imperato–McGinley J, Guerrero L, Gautier T, Peterson RE: Steroid 5 alpha–reductase deficiency in man: An inherited form of male pseudohermaphroidism. Science 1974;186:1213– 1215.
Walsh PC, Madden JD, Harrod MJ, Goldstein JL, MacDonald PC, Wilson JD: Familial incomplete male pseudohermaphroditism, type 2. Decreased dihydrotestosterone formation in pseudovaginal perineoscrotal hypospadias. N Engl J Med 1974;291:944–949.
Andersson S, Berman DM, Jenkins EP, Russell DW: Deletion of steroid 5 alpha–reductase 2 gene in male pseudohermaphroditism. Nature 1991;354:159–161.
Thigpen AE, Davis DL, Milatovich A, Mendonca BB, Imperato–McGinley J, Griffin JE, Francke U, Wilson JD, Russel DW: Molecular genetics of steroid 5 alpha–reductase 2 deficiency. J Clin Invest 1992;90:799–809.
Imperato–McGinley J, Sanchez RS, Spencer JR, Yee B, Vaughan ED: Comparison of the effects of the 5 alpha–reductase inhibitor finasteride and the antiandrogen flutamide on prostate and genital differentiation: Dose– response studies. Endocrinology 1992;131: 1149–1156.
Verhoeven G, Swinnen K, Cailleau J, Deboel L, Rombauts L, Heyns W: The role of cell–cell interactions in androgen action. J Steroid Biochem Mol Biol 1992;41:487–494.
Cunha GR: Role of mesenchymal–epithelial interactions in normal and abnormal development of the mammary gland and prostate. Cancer 1994;74:1030–1044.
McNeal J: Pathology of benign prostatic hyperplasia. Insight into etiology. Urol Clin North Am 1990;17:477–486.
Barrack ER, Berry SJ: DNA synthesis in the canine prostate: Effects of androgen and estrogen treatment. Prostate 1987;10:45–56.
McNeal JE: Origin and evolution of benign prostatic enlargement. Invest Urol 1978;15: 340–345.
Bartsch G, Frick J, Ruegg I, Bucher M, Holliger O, Oberholzer M, Rohr HP: Electron microscopic sterological analysis of the normal human prostate and of benign prostatic hyperplasia. J Urol 1979;122:481–486.
Bartsch G, Muller HR, Oberholzer M, Rohr HP: Light microscopic stereological analysis of the normal human prostate and of benign prostatic hyperplasia. J Urol 1979;122:487– 491.
Price H, McNeal JE, Stamey TA: Evolving patterns of tissue composition in benign prostatic hyperplasia as a function of specimen size. Hum Pathol 1990;21:578–585.
Krieg M, Klotzl G, Kaufmann J, Voigt KD: Stroma of human benign prostatic hyperplasia: Preferential tissue for androgen metabolism and oestrogen binding. Acta Endocrinol (Copenh) 1981;96:422–432.
Romijn J, Oishi K, Belt de Vries J, Schweikert H, Mulder E, Schröder F: Androgen metabolism and androgen receptors in separated epithelium and stroma of the human prostate; in Schröder F, de Voogt H (eds): Steroid Receptors, Metabolism and Prostatic Cancer. Amsterdam, Excerpta Medica, 1980, pp 134–139.
Bruchovsky N, Lieskovsky G: Increased ratio of 5 alpha–reductase:3 alpha (beta)–hydroxysteroid dehydrogenase activities in the hyperplastic human prostate. J Endocrinol 1979;80: 289–301.
Wright AS, Thomas LN, Douglas RC, Lazier CB, Rittmaster RS: Relative potency of testosterone and dihydrotestosterone in preventing atrophy and apoptosis in the prostate of the castrated rat. J Clin Invest 1996;98:2558–2563.
Grino PB, Griffin JE, Wilson JD: Testosterone at high concentrations interacts with the human androgen receptor similarly to dihydrotestosterone. Endocrinology 1990;126: 1165–1172.
Wright AS, Douglas RC, Thomas LN, Lazier CB, Rittmaster RS: Androgen–induced regrowth in the castrated rat ventral prostate: Role of 5 alpha–reductase. Endocrinology 1999;140:4509–4515.
Gormley GJ, Stoner E, Bruskewitz RC, Imperato–McGinley J, Walsh PC, McConnell JD, Andriole GL, Geller J, Bracken BR, Tenover JS, et al: The effect of finasteride in men with benign prostatic hyperplasia. The Finasteride Study Group (see comments). N Engl J Med 1992;327:1185–1191.
Rittmaster RS, Lemay A, Zwicker H, Capizzi TP, Winch S, Moore E, Gormley GJ: Effect of finasteride, a 5 alpha–reductase inhibitor, on serum gonadotropins in normal men. J Clin Endocrinol Metab 1992;75:484–488.
Beato M, Truss M, Chavez S: Control of transcription by steroid hormones. Ann NY Acad Sci 1996;784:93–123.
Fuller PJ: The steroid nuclear receptor superfamily: Mechanisms of diversity. FASEB J 1991;5:2243–2249.
Smith DF, Toft DO: Steroid receptors and their associated proteins. Mol Endocrinol 1993;7: 4–11.
Beato M: Transcriptional control by nuclear receptors. FASEB J 1991;5:2044–2051.
Rennie PS, Bruchovsky N, Leco KJ, Sheppard PC, Mcqueen SA, Cheng H, Snoek R, Hamel A, Bock ME, Macdonald BS, Nickel BE, Chang C, Liao S, Cattini PA, Matusik RJ: Characterization of two cis–acting DNA elements involved in the androgen regulation of the probasin gene. Mol Endocrinol 1993;7:23– 36.
Riegman PH, Vlietstra RJ, van der Korput JA, Brinkmann AO, Trapman J: The promoter of the prostate–specific antigen gene contains a functional androgen responsive element. Mol Endocrinol 1991;5:1921–1930.
Schneikert J, Peterziel H, Defossez PA, Klocker H, Launoit Y, Cato AC: Androgen receptor–Ets protein interaction is a novel mechanism for steroid hormone–mediated down–modulation of matrix metalloproteinase expression. J Biol Chem 1996;271:23907–23913.
Culig Z, Hobisch A, Cronauer MV, Hittmair A, Radmayr C, Bartsch G, Klocker H: Activation of the androgen receptor by polypeptide growth factors and cellular regulators. World J Urol 1995;13:285–289.
Culig Z, Hobisch A, Cronauer MV, Radmayr C, Hittmair A, Zhang J, Turnher M, Bartsch G, Klocker H: Regulation of prostatic growth and function by peptide growth factors. Prostate 1996;28:392–405.
Culig Z, Hobisch A, Hittmair A, Cronauer MV, Radmayr C, Zhang J, Bartsch G, Klocker H: Synergistic activation of androgen receptor by androgen and luteinizing hormone–releasing hormone in prostatic carcinoma cells. Prostate 1997;32:106–114.
Nakhla AM, Romas NA, Rosner W: Estradiol activates the prostate androgen receptor and prostate–specific antigen secretion through the intermediacy of sex hormone–binding globulin. J Biol Chem 1997;272:6838–6841.
Gregory CW, Kim D, Ye P, D’Ercole AJ, Pretlow TG, Mohler JL, French FS: Androgen receptor up–regulates insulin–like growth factor binding protein–5 (IGFBP–5) expression in a human prostate cancer xenograft. Endocrinology 1999;140:2372–2381.
Lin B, Ferguson C, White JT, Wang S, Vessella R, True LD, Hood L, Nelson PS: Prostate–localized and androgen–regulated expression of the membrane–bound serine protease TMPRSS2. Cancer Res 1999;59:4180–4184.
Nelson PS, Gan L, Ferguson C, Moss P, Gelinas R, Hood L, Wang K: Molecular cloning and characterization of prostase, and androgen–regulated serine protease with prostate–restricted expression. Proc Natl Acad Sci USA 1999;96:3114–3119.
Prescott JL, Blok L, Tindall DJ: Isolation and androgen regulation of the human homeobox cDNA, NKX3.1. Prostate 1998;35:71–80.
Lee JH, Sul CK, Kim YK, Hwang BD, Lim K: Differential regulation of protooncogene c–myc expression in rat ventral prostate after castration. Biochem Mol Biol Int 1999;47: 143–151.
Peterziel H, Mink S, Schonert A, Becker M, Klocker H, Cato A: Rapid signalling by androgen receptor in prostate cancer cells. Oncogene 1999;18:6322–6329.
Brown CJ, Goss SJ, Lubahn DB, Joseph DR, Wilson EM, French FS, Willard HF: Androgen receptor locus on the human X chromosome: Regional localization to Xq11–12 and description of a DNA polymorphism. Am J Hum Genet 1989;44:264–269.
Brown TR, Scherer PA, Chang YT, Migeon CJ, Ghirri P, Murono K, Zhou Z: Molecular genetics of human androgen insensitivity. Eur J Pediatr 1993;152:S62–S69.
Schweikert HU: The androgen resistance syndromes: Clinical and biochemical aspects. Eur J Pediatr 1993;152(suppl 2):S50–S57.
Gottlieb B, Lehvaslaiho H, Beitel LK, Lumbroso R, Pinsky L, Trifiro M: The Androgen Receptor Gene Mutations Database. Nucleic Acids Res 1998;26:234–238.
Geller J: Effect of finasteride, a 5 alpha–reductase inhibitor on prostate tissue androgens and prostate–specific antigen. J Clin Endocrinol Metab 1990;71:1552–1555.
McConnell JD, Wilson JD, George FW, Geller J, Pappas F, Stoner E: Finasteride, an inhibitor of 5 alpha–reductase, suppresses prostatic dihydrotestosterone in men with benign prostatic hyperplasia. J Clin Endocrinol Metab 1992; 74:505–508.
Norman RW, Coakes KE, Wright AS, Rittmaster RS: Androgen metabolism in men receiving finasteride before prostatectomy. J Urol 1993;150:1736–1739.
Imperato–McGinley J, Gautier T, Zirinsky K, Hom T, Palomo O, Stein E, Vaughan ED, Markisz JA, Ramirez de Arellano E, Kazam E: Prostate visualization studies in males homozygous and heterozygous for 5 alpha– reductase deficiency. J Clin Endocrinol Metab 1992;75:1022–1029.
Mahendroo MS, Russell DW: Male and female isoenzymes of steroid 5 alpha–reductase. Rev Reprod 1999;4:179–183.
Mahendroo MS, Cala KM, Russell DW: 5 alpha–reduced androgens play a key role in murine parturition. Mol Endocrinol 1996;10: 380–392.
Wilson JD, Griffin JE, Russell DW: Steroid 5 alpha–reductase 2 deficiency. Endocr Rev 1993;14:577–593.
Hudson PB, Boake R, Trachtenberg J, Romas NA, Rosenblatt S, Narayan P, Geller J, Lieber MM, Elhilali M, Norman R, Patterson L, Perreault JP, Malek GH, Bruskewitz RC, Roy JB, Ko A, Jacobsen CA, Stoner E: Efficacy of finasteride is maintained in patients with benign prostatic hyperplasia treated for 5 years. The North American Finasteride Study Group. Urology 1999;53:690–695.
Kaufman KD, Olsen EA, Whiting D, Savin R, DeVillez R, Bergfeld W, Price VH, Van Neste D, Roberts JL, Hordinsky M, Shapiro J, Binkowitz B, Gormley GJ: Finasteride in the treatment of men with androgenetic alopecia. Finasteride Male Pattern Hair Loss Study Group. J Am Acad Dermatol 1998;39:578– 589.
Andersson S, Russell DW: Structural and biochemical properties of clone and expressed human and rat steroid 5 alpha–reductases. Proc Natl Acad Sci USA 1990;87:3640–3644.
Normington K, Russell DW: Tissue distribution and kinetic characteristics of rat steroid 5 alpha–reductase isozymes. Evidence for distinct physiological functions. J Biol Chem 1992;267:19548–19554.
Boudon C, Lobaccaro JM, Lumbroso S, Lechevallier E, Mottet N, Gibelin B, Sultan C: 5 alpha–reductase activity in cultured epithelial and stromal cells from normal and hyperplastic human prostates – Effect of finasteride (Proscar), a 5 alpha–reductase inhibitor. Cell Mol Biol 1995;41:1007–1015.
Aumuller G, Eicheler W, Renneberg H, Adermann K, Vilja P, Forssmann WG: Immunocytochemical evidence for differential subcellular localization of 5 alpha–reductase isoen– zymes in human tissues. Acta Anat 1996; 156:241–252.
Bruchovsky N, Sadar MD, Akakura K, Goldenberg SL, Matsuoka K, Rennie PS: Characterization of 5 alpha–reductase gene expression in stroma and epithelium of human prostate. J Steroid Biochem Mol Biol 1996;59:397–404.
Berthaut I, Mestayer C, Portois MC, Cussenot O, Mowszowicz I: Pharmacological and molecular evidence for the expression of the two steroid 5 alpha–reductase isozymes in normal and hyperplastic human prostatic cells in culture. Prostate 1997;32:155–163.
Negri–Cesi P, Poletti A, Colciago A, Magni P, Martini P, Motta M: Presence of 5 alpha– reductase isozymes and aromatase in human prostate cancer cells and in benign prostate hyperplastic tissue. Prostate 1998;34:283–291.
Habib FK, Ross M, Bayne CW, Grigor K, Buck AC, Bollina P, Chapman K: The localisation and expression of 5 alpha–reductase types I and II mRNAs in human hyperplastic prostate and in prostate primary cultures. J Endocrinol 1998;156:509–517.
Kyprianou N, Isaacs JT: Biological significance of measurable androgen levels in the rat ventral prostate following castration. Prostate 1987;10:313–324.
Kyprianou N, Isaacs JT: Quantal relationship between prostatic dihydrotestosterone and prostatic cell content: Critical threshold concept. Prostate 1987;11:41–50.
Rittmaster RS, Magro KE, Manning AP, Norman RW, Lazier CB: Differential effect of 5 alpha–reductase inhibition and castration on androgen–regulated gene expression in rat prostate. Mol Endocrinol 1991;5:1023–1029.
Voigt W, Fernandez EP, Hsia SL: Transformation of testosterone into 17 beta–hydroxy–5 alpha–androstan–3–one by microsomal preparations of human skin. J Biol Chem 1970;245: 5594–5599.
Voigt W, Hsia SL: The antiandrogenic action of 4–androsten–3–one–17 beta–carboxylic acid and its methyl ester on hamster flank organ. Endocrinology 1973;92:1216–1222.
Rasmusson GH, Reynolds GF, Steinberg NG, Walton E, Patel GF, Liang T, Cascieri MA, Cheung HA, Brooks JR, Berman C: Azasteroids: Structure–activity relationships for inhibition of 5 alpha–reductase and of androgen receptor binding. J Med Chem 1986;29: 2298–2315.
Holt DA, Levy MA, Oh HJ, Erb JM, Heaslip JI, Brandt M, Lan–Hargest HY, Metcalf BW: Inhibition of steroid 5 alpha–reductase by unsatured 3–carboxysteroids. J Med Chem 1990; 33:943–950.
Nakai H, Tershima H, Arai A: Benzoylaminophenosybutanoic acid derivatives. Ono Pharmoaceutical, EP 0291 245 A2. Chem Abstr 110, 1988;212384t.
Brooks JR, Berman C, Garnes D, Giltinan D, Gordon LR, Malatesta PF, Primka RL, Reynolds GF, Rasmusson GH: Prostatic effects induced in dogs by chronic or acute oral administration of 5 alpha–reductase inhibitors. Prostate 1986;9:65–75.
Rittmaster RS, Stoner E, Thompson DL, Nance D, Lasseter KC: Effect of MK–906, a specific 5 alpha–reductase inhibitor, on serum androgens and androgen conjugates in normal men. J Androl 1989;10:259–262.
Vermeulen A, Giagulli VA, De Schepper P, Buntinx A, Stoner E: Hormonal effects of an orally active 4–azasteroid inhibitor of 5 alpha–reductase in humans. Prostate 1989;14:45–53.
Tian G, Mook RA Jr, Moss ML, Frye SV: Mechanism of time–dependent inhibition of 5 alpha–reductases by delta 1–4–azasteroids: Toward perfection of rates of time–dependent inhibition by using ligand–binding energies. Biochemistry 1995;34:13453–13459.
Frye SV, Haffner CD, Maloney PR, Hiner RN, Dorsey GF, Noe RA, Unwalla RJ, Batchelor KW, Bramson HN, Stuart JD, et al: Structure–activity relationships for inhibition of type 1 and 2 human 5 alpha–reductase and human adrenal 3 beta–hydroxy–delta 5–steroid dehydrogenase/3–keto–delta 5–steroid isomerase by 6–azaandrost–4–en–3– ones: Optimization of the C17 substituent. J Med Chem 1995;38: 2621–2627.
Moss ML, Kuzmic P, Stuart JD, Tian G, Peranteau AG, Frye SV, Kadwell SH, Kost TA, Overton LK, Patel IR: Inhibition of human steroid 5 alpha–reductases type I and II by 6–azasteroids: Structural determinants of one–step vs two–step mechanism. Biochemistry 1996;35:3457–3464.
Faller B, Farley D, Nick H: Finasteride: A slow–binding 5 alpha–reductase inhibitor. Biochemistry 1993;32:5705–5710.
Bull W, Garcia–Calvo M, Anderson S, Baginsky W, Chan H, Ellsworth D, RR M, Stearns R, Bakshi R, Rasmusson G, Tolmann R, Myers R, Kozarich J, Harris G: Mechanism–based inhibition of human steroid 5 alpha–reductase by finasteride: Enzyme–catalyzed formation of NADP–dihydrofinasteride, a potent bisubstrate analog inhibitor. J Am Chem Soc 1996;118: 2359–2365.
Rittmaster RS: Finasteride. N Engl J Med 1994;330:120–125.
Rittmaster RS, Norman RW, Thomas LN, Rowden G: Evidence for atrophy and apoptosis in the prostates of men given finasteride. J Clin Endocrinol Metab 1996;81:814–819.
Aarnisalo P, Palvimo JJ, Janne OA: CREB–binding protein in androgen receptor–mediated signaling. Proc Natl Acad Sci USA 1998;95:2122–2127.
Clark R, Hermann D, Gabriel H, Wilson T, Morrill B, Hobbs S: Effective suppression of dihydrotestosterone (DHT) by GI198745, a novel, dual 5 alpha–reductase inhibitor. J Urol 1999;161:1037.
White J: The results of double castration in hypertrophy of the prostate. Ann Surg 1885;25:1–59.
Cabot A: The question of castration for enlarged prostate. Am Surg 1896;26:265–285.
Huggins C, Stevens R: The effect of castration on benign hypertrophy of the prostate in men. J Urol 1940;43:705–714.
Finasteride (MK–906) in the treatment of benign prostatic hyperplasia. The Finasteride Study Group. Prostate 1993;22:291–299.
Stoner E: Three–year safety and efficacy data on the use of finasteride in the treatment of benign prostatic hyperplasia. Urology 1994; 43:292, discussion 292–294.
Lepor H, Stoner E: Long–term results of medical therapies for benign prostatic hyperplasia. Curr Opin Urol 1995;5:18–24.
Kriby RS, Bryan J, Eardley I, Christmas TJ, Liu S, Holmes SA, Vale JA, Shanmuganathan K, Webb JA: Finasteride in the treatment of benign prostatic hyperplasia. A urodynamic evaluation. Br J Urol 1992;70:65–72.
Tammela TL, Kontturi MJ: Urodynamic effects of finasteride in the treatment of bladder outlet obstruction due to benign prostatic hyperplasia. J Urol 1993;149:342–344.
Kirby RS, Vale J, Bryan J, Holmes K, Webb JA: Long–term urodynamic effects of finasteride in benign prostatic hyperplasia: A pilot study. Eur Urol 1993;24:20–26.
Nickel JC, Fradet Y, Boake RC, Pommerville PJ, Perreault JP, Afridi SK, Elhilali MM: Efficacy and safety of finasteride therapy for benign prostatic hyperplasia: Results of a 2–year randomized controlled trial (the PROSPECT study). CMAJ 1996;155:1251–1259.
Andersen JT, Ekman P, Wolf H, Beisland HO, Johansson JE, Kontturi M, Lehtonen T, Tveter K: Can finasteride reverse the progress of benign prostatic hyperplasia? A two–year placebo–controlled study. The Scandinavian BPH Study Group. Urology 1995;46:631– 637.
Andersen JT, Nickel JC, Marshall VR, Schulman CC, Boyle P: Finasteride significantly reduces acute urinary retention and need for surgery in patients with symptomatic benign prostatic hyperplasia. Urology 1997;49:839– 845.
McConnell JD, Bruskewitz R, Walsh P, Andriole G, Lieber M, Holtgrewe HL, Albertsen P, Roehrborn CG, Nickel JC, Wang DZ, Taylor AM, Waldstreicher J: The effect of finasteride on the risk of acute urinary retention and the need for surgical treatment among men with benign prostatic hyperplasia. Finasteride Long–Term Efficacy and Safety Study Group. N Engl J Med 1998;338:557–563.
Boyle P, Gould AL, Roehrborn CG: Prostate volume predicts outcome of treatment of benign prostatic hyperplasia with finasteride: Meta–analysis of randomized clinical trials. Urology 1996;48:398–405.
McConnell JD: Androgen ablation and blockade in the treatment of benign prostatic hyperplasia. Urol Clin North Am 1990;17:661– 670.
Shapiro E, Becich MJ, Hartanto V, Lepor H: The relative proportion of stromal and epithelial hyperplasia is related to the development of symptomatic benign prostate hyperplasia. J Urol 1992;147:1293–1297.
Barry MJ, Cockett AT, Holtgrewe HL, McConnell JD, Sihelnik SA, Winfield HN: Relationship of symptoms of prostatism to commonly used physiological and anatomical measures of the severity of benign prostatic hyperplasia. J Urol 1993;150:351–358.
Geller J: Benign prostatic hyperplasia: Pathogenesis and medical therapy. J Am Geriatr Soc 1991;39:1208–1216.
Gormley GJ, Stoner E, Rittmaster RS, Gregg H, Thompson DL, Lasseter KC, Vlasses PH, Stein EA: Effects of finasteride (MK–906), a 5 alpha–reductase inhibitor, on circulating androgens in male volunteers. J Clin Endocrinol Metab 1990;70:1136–1141.
Ohtawa M, Morikawa H, Shimazaki J: Pharmacokinetics and biochemical efficacy after single and multiple oral administration of N–(2–methyl–2–propyl)–3–oxo–4–aza–5–alpha–androst–1–ene–17–beta–carboxamide, a new type of specific competitive inhibitor of testosterone 5–alpha–reductase, in volunteers. Eur J Drug Metab Pharmacokinet 1991;16:15–21.
De Schepper PJ, Imperato–McGinley J, Van Hecken A, De Lepeleire I, Buntinx A, Carlin J, Gressi MH, Stoner E: Hormonal effects, tolerability, and preliminary kinetics in men of MK–906, a 5 alpha–reductase inhibitor. Steroids 1991;56:469–471.
Roehrborn C, Boyle P, Gabriel H, Hobbs S, Wilson T, Wolford E, Clark R: Relationship between serum PSA and total prostate and transition zone volume in men with clinical BPH. J Urol 1999;161:abstract 1405.
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