Skip to content
Licensed Unlicensed Requires Authentication Published by De Gruyter June 6, 2015

Finasteride, not tamsulosin, increases severity of erectile dysfunction and decreases testosterone levels in men with benign prostatic hyperplasia

Abdulmaged M. Traish, Karim Sultan Haider, Gheorghe Doros and Ahmad Haider


Background: 5α-reductase inhibitors (5α-RIs) (finasteride and dutasteride) have been proven useful in treatment of lower urinary tract symptoms (LUTS) related to benign prostatic hyperplasia (BPH). However, these inhibitors exert undesirable sexual side effects and, in some cases, these effects are persistent. There is considerable disagreement with regard to whether the adverse side effects resolve with continuous treatment.

Aim: To investigate the long-term adverse effects of finasteride treatment in men with BPH on erectile function and to compare these adverse effects in men treated with the α1-adrenergic receptor blocker, tamsolusin.

Methods: In this retrospective registry study, a cohort of 470 men aged between 47 and 68 years (mean 57.78±4.81) were treated with finasteride (5 mg/day). A second cohort of 230 men aged between 52 and 72 years (mean 62.62±4.65) were treated with tamsulosin (0.4 mg). All men were followed up for 45 months. At intervals of 3 months and at each visit, plasma testosterone (T) levels and the international index of erectile function (IIEF-EF) questionnaire scores were determined.

Results: Long-term treatment with finasteride therapy is associated with worsening of erectile dysfunction (ED) as shown by the significant decrease in the IIEF-EF scores in men treated with finasteride. No worsening of ED was observed in men treated with tamsulosin. The increase in ED due to finasteride did not resolve with continued treatment with finasteride. Most importantly, long-term finasteride therapy resulted in reduction in total T levels, contributing to a state of hypogonadism. On the contrary, no changes in T levels were noted in men treated with tamsolusin.

Conclusion: Our findings suggest that in men with BPH, long-term finasteride therapy but not tamsulosin results in worsening of ED and reduces total T concentrations. Clinicians are urged to discuss the impact of 5α-RIs therapy on sexual function with their patients before commencing this therapy.

Corresponding author: Abdulmaged M. Traish, MBA, PhD, Department of Biochemistry and Department of Urology, Boston University School of Medicine, 715 Albany Street; A502, Boston, MA 02478, USA, E-mail:


1. Roehrborn CG, Perez IO, Roos EP, Calomfirescu N, Brotherton B, Wang F, Palacios JM, Vasylyev A, Manyak MJ. Efficacy and safety of a fixed-dose combination of dutasteride and tamsulosin treatment (Duodart™) compared with watchful waiting with initiation of tamsulosin therapy if symptoms do not improve, both provided with lifestyle advice, in the management of treatment-naïve men with moderately symptomatic benign prostatic hyperplasia: 2-year CONDUCT study results. BJU Int 2015; Jan 7 [Ahead of print].10.1111/bju.13033Search in Google Scholar

2. Bechis SK, Otsetov AG, Ge R, Olumi AF. Personalized medicine for the management of benign prostatic hyperplasia. J Urol 2014;192:16–23.10.1016/j.juro.2014.01.114Search in Google Scholar

3. Gupta AK, Charrette A. The efficacy and safety of 5alpha-reductase inhibitors in androgenetic alopecia: a network meta-analysis and benefit-risk assessment of finasteride and dutasteride. J Dermatol Treat 2014;25:156–61.10.3109/09546634.2013.813011Search in Google Scholar

4. Mella JM, Perret MC, Manzotti M, Catalano HN, Guyatt G. Efficacy and safety of finasteride therapy for androgenetic alopecia: a systematic review. Arch Dermatol 2010;146:1141–50.10.1001/archdermatol.2010.256Search in Google Scholar

5. Erdemir F, Harbin A, Hellstrom WJ. 5-alpha reductase inhibitors and erectile dysfunction: the connection. J Sex Med 2008;5:2917–24.10.1111/j.1743-6109.2008.01001.xSearch in Google Scholar

6. Traish AM, Hassani J, Guay AT, Zitzmann M, Hansen ML. Adverse side effects of 5alpha-reductase inhibitors therapy: persistent diminished libido and erectile dysfunction and depression in a subset of patients. J Sex Med 2011;8:872–84.10.1111/j.1743-6109.2010.02157.xSearch in Google Scholar

7. Traish AM. 5alpha-reductases in human physiology: an unfolding story. Endocr Pract 2012;18:965–75.10.4158/EP12108.RASearch in Google Scholar

8. Traish AM, Mulgaonkar A, Giordano N. The dark side of 5α-reductase inhibitors’ therapy: sexual dysfunction, high Gleason grade prostate cancer and depression. Korean J Urol 2014;55:367–79.10.4111/kju.2014.55.6.367Search in Google Scholar

9. Irwig MS, Kolukula S. Persistent sexual side effects of finasteride for male pattern hair loss. J Sex Med 2011;8:1747–53.10.1111/j.1743-6109.2011.02255.xSearch in Google Scholar

10. Irwig MS. Persistent sexual side effects of finasteride: could they be permanent? J Sex Med 2012;9:2927–32.10.1111/j.1743-6109.2012.02846.xSearch in Google Scholar

11. Irwig MS. Depressive symptoms and suicidal thoughts among former users of finasteride with persistent sexual side effects. J Clin Psychiatry 2012;73:1220–3.10.4088/JCP.12m07887Search in Google Scholar

12. Irwig MS. Decreased alcohol consumption among former male users of finasteride with persistent sexual side effects: a preliminary report. Alcohol Clin Exp Res 2013;37:1823–6.10.1111/acer.12177Search in Google Scholar

13. Irwig MS. Androgen levels and semen parameters among former users of finasteride with persistent sexual adverse effects. J Am Med Assoc Dermatol 2014;150:1361–3.10.1001/jamadermatol.2014.1830Search in Google Scholar

14. Gur S, Kadowitz PJ, Hellstrom WJ. Effects of 5-alpha reductase inhibitors on erectile function, sexual desire and ejaculation. Expert Opin Drug Saf 2013;12:81–90.10.1517/14740338.2013.742885Search in Google Scholar

15. Ganzer CA, Jacobs AR, Iqbal F. Persistent sexual, emotional, and cognitive impairment post-finasteride: a survey of men reporting symptoms. Am J Mens Health 2015;9:222–8.10.1177/1557988314538445Search in Google Scholar

16. Roehrborn CG, Boyle P, Nickel JC, Hoefner K, Andriole G; ARIA3001 ARIA3002 and ARIA3003 Study Investigators. Efficacy and safety of a dual inhibitor of 5-alpha-reductase types 1 and 2 (dutasteride) in men with benign prostatic hyperplasia. Urology 2002;60:434–41.10.1016/S0090-4295(02)01905-2Search in Google Scholar

17. 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). PROscar Safety Plus Efficacy Canadian Two year Study. CMAJ 1996;155:1251–9.Search in Google Scholar

18. Wilton L, Pearce G, Edet E, Freemantle S, Stephens MD, Mann RD. The safety of finasteride used in benign prostatic hypertrophy: a non-interventional observational cohort study in 14,772 patients. Br J Urol 1996;78:379–4.10.1046/j.1464-410X.1996.00091.xSearch in Google Scholar

19. Tenover JL, Pagano GA, Morton AS, Liss CL, Byrnes CA. Efficacy and tolerability of finasteride in symptomatic benign prostatic hyperplasia: a primary care study. Primary Care Investigator Study Group. Clin Ther 1997;19:243–58.10.1016/S0149-2918(97)80113-0Search in Google Scholar

20. 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;53:690–5.10.1016/S0090-4295(98)00666-9Search in Google Scholar

21. Bruskewitz R, Girman CJ, Fowler J, Rigby OF, Sullivan M, Bracken RB, Fusilier HA, Kozlowski D, Kantor SD, Johnson EL, Wang DZ, Waldstreicher J. Effect of finasteride on bother and other health-related quality of life aspects associated with benign prostatic hyperplasia. PLESS Study Group. Proscar Long-term Efficacy and Safety Study. Urology 1999;54:670–8.10.1016/S0090-4295(99)00209-5Search in Google Scholar

22. Edwards JE, Moore RA. Finasteride in the treatment of clinical benign prostatic hyperplasia: a systematic review of randomized trials. BMC Urol 2002;2:14.10.1186/1471-2490-2-14Search in Google Scholar

23. Thompson IM, Goodman PJ, Tangen CM, Lucia MS, Miller GJ, Ford LG, Lieber MM, Cespedes RD, Atkins JN, Lippman SM, Carlin SM, Ryan A, Szczepanek CM, Crowley JJ, Coltman CA Jr. The influence of finasteride on the development of prostate cancer. N Engl J Med 2003;349:215–24.10.1056/NEJMoa030660Search in Google Scholar

24. Wessells H, Roy J, Bannow J, Grayhack J, Matsumoto AM, Tenover L, Herlihy R, Fitch W, Labasky R, Auerbach S, Parra R, Rajfer J, Culbertson J, Lee M, Bach MA, Waldstreicher J. Incidence and severity of sexual adverse experiences in finasteride and placebo-treated men with benign prostatic hyperplasia. Urology 2003;61:579–84.10.1016/S0090-4295(02)02401-9Search in Google Scholar

25. Andriole GL, Kirby R. Safety and tolerability of the dual 5alpha-reductase inhibitor dutasteride in the treatment of benign prostatic hyperplasia. Eur Urol 2003;44:82–8.10.1016/S0302-2838(03)00198-2Search in Google Scholar

26. AUA guideline on management of benign prostatic hyperplasia (2003). Chapter 1: Diagnosis and treatment recommendations. J Urol 2003;170:530–47.10.1097/01.ju.0000078083.38675.79Search in Google Scholar

27. Desgrandchamps F, Droupy S, Irani J, Saussine C, Comenducci A. Effect of dutasteride on the symptoms of benign prostatic hyperplasia, and patient quality of life and discomfort, in clinical practice. BJU Int 2006;98:83–8.10.1111/j.1464-410X.2006.06241.xSearch in Google Scholar

28. Siami P, Roehrborn CG, Barkin J, Damiao R, Wyczolkowski M, Duggan A, Major-Walker K, Morrill BB. Combination therapy with dutasteride and tamsulosin in men with moderate-to-severe benign prostatic hyperplasia and prostate enlargement: the CombAT (Combination of Avodart and Tamsulosin) trial rationale and study design. Contemp Clin Trials 2007;28:770–9.10.1016/j.cct.2007.07.008Search in Google Scholar

29. Roehrborn CG, Siami P, Barkin J, Damiao R, Major-Walker K, Morrill B, Montorsi F. The effects of dutasteride, tamsulosin and combination therapy on lower urinary tract symptoms in men with benign prostatic hyperplasia and prostatic enlargement: 2-year results from the CombAT study. J Urol 2008;179:616–21; discussion 21.10.1016/j.juro.2007.09.084Search in Google Scholar

30. Canguven O, Burnett AL. The effect of 5 alpha-reductase inhibitors on erectile function. J Androl 2008;29:514–23.10.2164/jandrol.108.005025Search in Google Scholar

31. Andriole GL, Bostwick DG, Brawley OW, Gomella LG, Marberger M, Montorsi F, Pettaway CA, Tammela TL, Teloken C, Tindall DJ, Somerville MC, Wilson TH, Fowler IL, Rittmaster RS. Effect of dutasteride on the risk of prostate cancer. N Engl J Med 2010;362:1192–202.10.1056/NEJMoa0908127Search in Google Scholar

32. Roehrborn CG, Andriole GL, Wilson TH, Castro R, Rittmaster RS. Effect of dutasteride on prostate biopsy rates and the diagnosis of prostate cancer in men with lower urinary tract symptoms and enlarged prostates in the Combination of Avodart and Tamsulosin trial. Eur Urol 2011;59:244–9.10.1016/j.eururo.2010.10.040Search in Google Scholar

33. Chi BH, Kim SC. Changes in sexual function in benign prostatic hyperplasia patients taking dutasteride: 1-year follow-up results. Korean J Urol 2011;52:632–6.10.4111/kju.2011.52.9.632Search in Google Scholar

34. Kaplan SA, Chung DE, Lee RK, Scofield S, Te AE. A 5-year retrospective analysis of 5alpha-reductase inhibitors in men with benign prostatic hyperplasia: finasteride has comparable urinary symptom efficacy and prostate volume reduction, but less sexual side effects and breast complications than dutasteride. Int J Clin Pract 2012;66:1052–5.10.1111/j.1742-1241.2012.03010.xSearch in Google Scholar

35. Gubelin Harcha W, Barboza Martínez J, Tsai TF, Katsuoka K, Kawashima M, Tsuboi R, Barnes A, Ferron-Brady G, Chetty D. A randomized, active- and placebo-controlled study of the efficacy and safety of different doses of dutasteride versus placebo and finasteride in the treatment of male subjects with androgenetic alopecia. J Am Acad Dermatol 2014;S0190-9622:01171–7.Search in Google Scholar

36. Fwu CW, Eggers PW, Kirkali Z, McVary KT, Burrows PK, Kusek JW. Change in sexual function in men with lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH) associated with long-term treatment with doxazosin, finasteride, and combined therapy. J Urol 2014;191:1828–34.10.1016/j.juro.2013.12.014Search in Google Scholar

37. Irwig MS. Persistent sexual and non-sexual adverse effects of finasteride in younger men. Sex Med Rev 2014;2:24–35.10.1002/smrj.19Search in Google Scholar

38. Traish AM, Guay AT. Are androgens critical for penile erections in humans? Examining the clinical and preclinical evidence. J Sex Med 2006;3:382–404.10.1111/j.1743-6109.2006.00245.xSearch in Google Scholar

39. Traish AM, Goldstein I, Kim NN. Testosterone and erectile function: from basic research to a new clinical paradigm for managing men with androgen insufficiency and erectile dysfunction. Eur Urol 2007;52:54–70.10.1016/j.eururo.2007.02.034Search in Google Scholar

40. Oztekin CV, Gur S, Abdulkadir NA, Lokman U, Akdemir AO, Cetinkaya M, Hellstrom WJ. Incomplete recovery of erectile function in rat after discontinuation of dual 5-alpha reductase inhibitor therapy. J Sex Med 2012;9:1773–81.10.1111/j.1743-6109.2012.02759.xSearch in Google Scholar

41. Pinsky MR, Gur S, Tracey AJ, Harbin A, Hellstrom WJ. The effects of chronic 5-alpha-reductase inhibitor (dutasteride) treatment on rat erectile function. J Sex Med 2011;8:3066–74.10.1111/j.1743-6109.2011.02425.xSearch in Google Scholar

42. Zhang MG, Wang XJ, Shen ZJ, Gao PJ. Long-term oral administration of 5alpha-reductase inhibitor attenuates erectile function by inhibiting autophagy and promoting apoptosis of smooth muscle cells in corpus cavernosum of aged rats. Urology 2013;82:743 e9–15.10.1016/j.urology.2013.02.045Search in Google Scholar

43. Mainwaring WI. The mechanism of action of androgens. Monogr Endocrinol 1977;10:1–178.10.1007/978-3-642-88429-0_1Search in Google Scholar

44. Bradshaw WG, Baum MJ, Awh CC. Attenuation by a 5 alpha-reductase inhibitor of the activational effect of testosterone propionate on penile erections in castrated male rats. Endocrinology 1981;109:1047–51.10.1210/endo-109-4-1047Search in Google Scholar

45. Gray GD, Smith ER, Davidson JM. Hormonal regulation of penile erection in castrated male rats. Physiol Behav 1980;24:463–8.10.1016/0031-9384(80)90237-1Search in Google Scholar

46. Hart BL. Effects of testosterone propionate and dihydrotestosterone on penile morphology and sexual reflexes of spinal male rats. Horm Behav 1973;4:239–46.10.1016/0018-506X(73)90008-1Search in Google Scholar

47. Hart BL. Activation of sexual reflexes of male rats by dihydrotestosterone but not estrogen. Physiol Behav 1979;23:107–9.10.1016/0031-9384(79)90129-XSearch in Google Scholar

48. Mantzoros CS, Georgiadis EI, Trichopoulos D. Contribution of dihydrotestosterone to male sexual behaviour. Br Med J 1995;310:1289–91.10.1136/bmj.310.6990.1289Search in Google Scholar

49. Saksena SK, Lau IF, Chang MC. The inhibition of the conversion of testosterone into 5alpha-dihydrotestosterone in the reproductive organs of the male rat. Steroids 1976;27:751–7.10.1016/0039-128X(76)90135-5Search in Google Scholar

50. Baum MJ. A comparison of the effects of methyltrienolone (R 1881) and 5 alpha-dihydrotestosterone on sexual behavior of castrated male rats. Horm Behav 1979;13:165–74.10.1016/0018-506X(79)90055-2Search in Google Scholar

51. Lugg JA, Rajfer J, Gonzalez-Cadavid NF. Dihydrotestosterone is the active androgen in the maintenance of nitric oxide-mediated penile erection in the rat. Endocrinology 1995;136:1495–501.10.1210/endo.136.4.7534702Search in Google Scholar

52. Penson DF, Ng C, Rajfer J, Gonzalez-Cadavid NF. Adrenal control of erectile function and nitric oxide synthase in the rat penis. Endocrinology 1997;138:3925–32.10.1210/endo.138.9.5402Search in Google Scholar

53. Package Insert from Merck. Highlights of prescribing information. These highlights do not include all the information needed to use PROSCAR safely and effectively. See full prescribing information for PROSCAR. PROSCAR® (finasteride) Tablets Initial US. Approval: 1992. Revised: 09/2013Search in Google Scholar

54. Tsukamoto T, Endo Y, Narita M. Efficacy and safety of dutasteride in Japanese men with benign prostatic hyperplasia. Int J Urol 2009;16:745–50.10.1111/j.1442-2042.2009.02357.xSearch in Google Scholar

55. Amory JK, Anawalt BD, Matsumoto AM, Page ST, Bremner WJ, Wang C, Swerdloff RS, Clark RV. The effect of 5a-reductase inhibition with dutasteride and finasteride on bone mineral density, serum lipoproteins, hemoglobin, prostate specific antigen and sexual function in healthy young men. J Urol 2008;179:2333–8.10.1016/j.juro.2008.01.145Search in Google Scholar

56. Debruyne F, Barkin J, van Erps P, Reis M, Tammela TL, Roehrborn C; ARIA3001, ARIA3002 and ARIB3003 Study Investigators. Efficacy and safety of long-term treatment with the dual 5 alpha-reductase inhibitor dutasteride in men with symptomatic benign prostatic hyperplasia. Eur Urol 2004;46:488–94.10.1016/j.eururo.2004.05.008Search in Google Scholar

57. Na Y, Ye Z, Zhang S; Chinese Dutasteride Phase III Trial (ARIA108898) Study Group. Efficacy and safety of dutasteride in Chinese adults with symptomatic benign prostatic hyperplasia: a randomized, double-blind, parallel-group, placebo-controlled study with an open-label extension. Clin Drug Investig 2012;32:29–39.10.2165/11593750-000000000-00000Search in Google Scholar

58. Glina S, Roehrborn CG, Esen A, Plekhanov A, Sorsaburu S, Henneges C, Büttner H, Viktrup L. Sexual function in men with lower urinary tract symptoms and prostatic enlargement secondary to benign prostatic hyperplasia: results of a 6-month, randomized, double-blind, placebo-controlled study of tadalafil coadministered with finasteride. J Sex Med 2015;12:129–38.10.1111/jsm.12714Search in Google Scholar

59. Cappelleri JC, Rosen RC, Smith MD, Mishra A, Osterloh IH. Diagnostic evaluation of the erectile function domain of the International Index of Erectile Function. Urology 1999;54:346–51.10.1016/S0090-4295(99)00099-0Search in Google Scholar

60. Haider A, Zitzmann M, Doros G, Isbarn H, Hammerer P, Yassin A. Incidence of prostate cancer in hypogonadal men receiving testosterone therapy: observations from 5-year median follow up of 3 registries. J Urol 2015;193:80–6.10.1016/j.juro.2014.06.071Search in Google Scholar

61. Rosen RC, Allen KR, Ni X, Araujo AB. Minimal clinically important differences in the erectile function domain of the International Index of Erectile Function scale. Eur Urol 2011;60:1010–6.10.1016/j.eururo.2011.07.053Search in Google Scholar

62. Norman RW, Coakes KE, Wright AS, Rittmaster RS. Androgen metabolism in men receiving finasteride before prostatectomy. J Urol 1993;150:1736–9.10.1016/S0022-5347(17)35882-2Search in Google Scholar

63. Matzkin H, Chen J, Weisman Y, Goldray D, Pappas F, Jaccard N, Braf Z. Prolonged treatment with finasteride (a 5 alpha-reductase inhibitor) does not affect bone density and metabolism. Clin Endocrinol (Oxf) 1992;37:432–6.10.1111/j.1365-2265.1992.tb02355.xSearch in Google Scholar

64. 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;74:505–8.Search in Google Scholar

65. Dallob AL, Sadick NS, Unger W, Lipert S, Geissler LA, Gregoire SL, Nguyen HH, Moore EC, Tanaka WK. The effect of finasteride, a 5 alpha-reductase inhibitor, on scalp skin testosterone and dihydrotestosterone concentrations in patients with male pattern baldness. J Clin Endocrinol Metab 1994;79:703–6.Search in Google Scholar

66. Van Hecken A, Depré M, Schwartz JI, Tjandramaga TB, Winchell GA, De Lepeleire I, Ng J, De Schepper PJ. Plasma concentrations and effect on testosterone metabolism after single doses of MK-0434, a steroid 5 alpha-reductase inhibitor, in healthy subjects. Eur J Clin Pharmacol 1994;46:123–6.10.1007/BF00199874Search in Google Scholar

67. Schwartz JI, Tanaka WK, Wang DZ, Ebel DL, Geissler LA, Dallob A, Hafkin B, Gertz BJ. MK-386, an inhibitor of 5alpha-reductase type 1, reduces dihydrotestosterone concentrations in serum and sebum without affecting dihydrotestosterone concentrations in semen. J Clin Endocrinol Metab 1997;82:1373–7.Search in Google Scholar

68. Bayram F, Müderris II, Sahin Y, Keleştimur F. Finasteride treatment for one year in 35 hirsute patients. Exp Clin Endocrinol Diabetes 1999;107:195–7.10.1055/s-0029-1212097Search in Google Scholar

69. Denti L, Pasolini G, Cortellini P, Sanfelici L, Benedetti R, Cecchetti A, Ferretti S, Bruschieri L, Ablondi F, Valenti G. Changes in HDL-cholesterol and lipoprotein Lp(a) after 6-month treatment with finasteride in males affected by benign prostatic hyperplasia (BPH). Atherosclerosis 2000;152:159–66.10.1016/S0021-9150(99)00442-6Search in Google Scholar

70. Drake L, Hordinsky M, Fiedler V, Swinehart J, Unger WP, Cotterill PC, Thiboutot DM, Lowe N, Jacobson C, Whiting D, Stieglitz S, Kraus SJ, Griffin EI, Weiss D, Carrington P, Gencheff C, Cole GW, Pariser DM, Epstein ES, Tanaka W, Dallob A, Vandormael K, Geissler L, Waldstreicher J. The effects of finasteride on scalp skin and serum androgen levels in men with androgenetic alopecia. J Am Acad Dermatol 1999;41:550–4.Search in Google Scholar

71. Clark RV, Hermann DJ, Cunningham GR, Wilson TH, Morrill BB, Hobbs S. Marked suppression of dihydrotestosterone in men with benign prostatic hyperplasia by dutasteride, a dual 5alpha-reductase inhibitor. J Clin Endocrinol Metab 2004;89:2179–84.10.1210/jc.2003-030330Search in Google Scholar

72. Ryu HK, Kim KM, Yoo EA, Sim WY, Chung BC. Evaluation of androgens in the scalp hair and plasma of patients with male-pattern baldness before and after finasteride administration. Br J Dermatol 2006;154:730–4.10.1111/j.1365-2133.2005.07072.xSearch in Google Scholar

73. Upreti R, Hughes KA, Livingstone DE, Gray CD, Minns FC, Macfarlane DP, Marshall I, Stewart LH, Walker BR, Andrew R. 5α-reductase type 1 modulates insulin sensitivity in men. J Clin Endocrinol Metab 2014;99:E1397–406.10.1210/jc.2014-1395Search in Google Scholar

74. Caserini M, Radicioni M, Leuratti C, Annoni O, Palmieri R. A novel finasteride 0.25% topical solution for androgenetic alopecia: pharmacokinetics and effects on plasma androgen levels in healthy male volunteers. Int J Clin Pharmacol Ther 2014;52:842–9.10.5414/CP202119Search in Google Scholar

75. Vermeulen A, Giagulli VA, De Schepper P, Buntinx A. Hormonal effects of a 5 alpha-reductase inhibitor (finasteride) on hormonal levels in normal men and in patients with benign prostatic hyperplasia. Eur Urol 1991;20(Suppl. 1):82–6.10.1159/000471752Search in Google Scholar

76. Fruzzetti F, de Lorenzo D, Parrini D, Ricci C. Effects of finasteride, a 5 alpha-reductase inhibitor, on circulating androgens and gonadotropin secretion in hirsute women. J Clin Endocrinol Metab 1994;79:831–5.Search in Google Scholar

77. Rittmasster RS, Stoner R, Thompson DL, Nance D, Lasseter II KC. Effect of MK-906, a specific 5α-reductase inhibitor, on serum androgens and androgen conjugates in normal men. J Androl 1989;10:259–62.10.1002/j.1939-4640.1989.tb00097.xSearch in Google Scholar

78. Geller J. Effect of finasteride, a 5 alpha-reductase inhibitor on prostate tissue androgens and prostate-specific antigen. J Clin Endocrinol Metab 1990;71:1552–5.10.1210/jcem-71-6-1552Search in Google Scholar

79. 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;75:484–8.Search in Google Scholar

80. Zhao XF, Yang Y, Wang W, Qiu Z, Zhang P, Wang B. Effects of competitive and noncompetitive 5α-reductase inhibitors on serum and intra-prostatic androgens in beagle dogs. Chin Med J (Engl) 2013;126:711–5.Search in Google Scholar

81. Olsen EA, Hordinsky M, Whiting D, Stough D, Hobbs S, Ellis ML, Wilson T, Rittmaster RS; Dutasteride Alopecia Research Team. The importance of dual 5alpha-reductase inhibition in the treatment of male pattern hair loss: results of a randomized placebo-controlled study of dutasteride versus finasteride. J Am Acad Dermatol 2006;55:1014–23.10.1016/j.jaad.2006.05.007Search in Google Scholar

82. Roehrborn CG, Lee M, Meehan A, Waldstreicher J; PLESS Study Group. Effects of finasteride on serum testosterone and body mass index in men with benign prostatic hyperplasia. Urology 2003;62:894–9.10.1016/S0090-4295(03)00661-7Search in Google Scholar

83. Hong SK, Min GE, Ha SB, Doo SH, Kang MY, Park HJ, Yoon CY, Jeong SJ, Byun SS, Lee SE. Effect of the dual 5alpha-reductase inhibitor, dutasteride, on serum testosterone and body mass index in men with benign prostatic hyperplasia. BJU Int 2010;105:970–4.10.1111/j.1464-410X.2009.08915.xSearch in Google Scholar

84. Matsumoto AM, Tenover L, McClung M, Mobley D, Geller J, Sullivan M, Grayhack J, Wessells H, Kadmon D, Flanagan M, Zhang GK, Schmidt J, Taylor AM, Lee M, Waldstreicher J; Pless Study Group. The long-term effect of specific type II 5alpha-reductase inhibition with finasteride on bone mineral density in men: results of a 4-year placebo controlled trial. J Urol 2002;167:2105–8.10.1016/S0022-5347(05)65095-1Search in Google Scholar

85. Stanczyk FZ, Azen CG, Pike MC. Effect of finasteride on serum levels of androstenedione, testosterone and their 5α-reduced metabolites in men at risk for prostate cancer. J Steroid Biochem Mol Biol 2013;138:10–6.10.1016/j.jsbmb.2013.02.015Search in Google Scholar

86. Uygur MC, Arik AI, Altuğ U, Erol D. Effects of the 5 alpha-reductase inhibitor finasteride on serum levels of gonadal, adrenal, and hypophyseal hormones and its clinical significance: a prospective clinical study. Steroids 1998;63:208–13.10.1016/S0039-128X(98)00005-1Search in Google Scholar

87. Schwartz JI, Van Hecken A, De Schepper PJ, De Lepeleire I, Lasseter KC, Shamblen EC, Winchell GA, Constanzer ML, Chavez CM, Wang DZ, Ebel DL, Justice SJ, Gertz BJ. Effect of MK-386, a novel inhibitor of type 1 5 alpha-reductase, alone and in combination with finasteride, on serum dihydrotestosterone concentrations in men. J Clin Endocrinol Metab 1996;81:2942–7.Search in Google Scholar

88. Kacker R, Harisaran V, Given L, Miner M, Rittmaster R, Morgentaler A. Dutasteride in men receiving testosterone therapy: a randomised, double-blind study. Andrologia 2015;47:148–52.10.1111/and.12237Search in Google Scholar

89. Fwu C-W, Eggers P W,Kaplan SA, Kirkali Z, Lee JY, Kusek JW. Long-term effects of doxazosin, finasteride and combination therapy on quality of life in men with benign prostatic hyperplasia. J Urol 2013;190:187–93.10.1016/j.juro.2013.01.061Search in Google Scholar

90. Livingstone DE, Barat P, Di Rollo EM, Rees GA, Weldin BA, Rog-Zielinska EA, MacFarlane DP, Walker BR, Andrew R. 5α-Reductase type 1 deficiency or inhibition predisposes to insulin resistance, hepatic steatosis and liver fibrosis in rodents. Diabetes 2015;46:447–58.10.2337/db14-0249Search in Google Scholar

91. Livingstone DE, Di Rollo EM, Yang C, Codrington LE, Mathews JA, Kara M, Hughes KA, Kenyon CJ, Walker BR, Andrew R. Relative adrenal insufficiency in mice deficient in 5α-reductase 1. J Endocrinol 2014;222:257–66.10.1530/JOE-13-0563Search in Google Scholar

92. Traish AM, Guay AT, Zitzmann M. 5α-Reductase inhibitors alter steroid metabolism and may contribute to insulin resistance, diabetes, metabolic syndrome and vascular disease: a medical hypothesis. Horm Mol Biol Clin Investig 2014;20:73–80.10.1515/hmbci-2014-0025Search in Google Scholar

93. 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;34:13453–9.10.1021/bi00041a024Search in Google Scholar

94. Thigpen AE, Russell DW. Four-amino acid segment in steroid 5 alpha-reductase 1 confers sensitivity to finasteride, a competitive inhibitor. J Biol Chem 1992;267:8577–83.10.1016/S0021-9258(18)42482-9Search in Google Scholar

95. Zlotta AR, Teillac P, Raynaud JP, Schulman CC. Evaluation of male sexual function in patients with lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH) treated with a phytotherapeutic agent (Permixon), tamsulosin or finasteride. Eur Urol 2005;48:269–76.10.1016/j.eururo.2005.03.029Search in Google Scholar

96. Cunningham GR, Hirshkowitz M. Inhibition of steroid 5 alpha-reductase with finasteride: sleep-related erections, potency, and libido in healthy men. J Clin Endocrinol Metab 1995;80:1934–40.Search in Google Scholar

97. Park T, Choi JY. Efficacy and safety of dutasteride for the treatment of symptomatic benign prostatic hyperplasia (BPH): a systematic review and meta-analysis. World J Urol 2014;32:1093–105.10.1007/s00345-014-1258-9Search in Google Scholar

98. 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;338:557–63.10.1056/NEJM199802263380901Search in Google Scholar

99. Moinpour CM, Darke AK, Donaldson GW, Thompson IM Jr, Langley C, Ankerst DP, Patrick DL, Ware JE Jr, Ganz PA, Shumaker SA, Lippman SM, Coltman CA Jr. Longitudinal analysis of sexual function reported by men in the Prostate Cancer Prevention Trial. J Natl Cancer Inst 2007;99:1025–35.10.1093/jnci/djm023Search in Google Scholar

100. Belknap SM, Aslam I, Kiguradze T, Temps WH, Yarnold PR, Cashy J, Brannigan RE, Micali G, Nardone B, West DP. Adverse Event Reporting in Clinical Trials of Finasteride for Androgenic Alopecia: A Meta-analysis. JAMA Dermatol. 2015 Apr 1. doi: 10.1001/jamadermatol.2015.36. [Epub ahead of print].10.1001/jamadermatol.2015.36Search in Google Scholar

101. Moore TJ. Finasteride and the Uncertainties of Establishing Harms. JAMA Dermatol. 2015 Apr 1. doi: 10.1001/jamadermatol.2015.37. [Epub ahead of print].10.1001/jamadermatol.2015.37Search in Google Scholar

Received: 2015-4-2
Accepted: 2015-5-6
Published Online: 2015-6-6
Published in Print: 2015-9-1

©2015 by De Gruyter