{{Short description|Hormone replacement medication}} {{Use dmy dates|date=March 2024}} {{cs1 config |name-list-style=vanc |display-authors=6}} {{Infobox drug | Verifiedfields = verified | Watchedfields = verified | verifiedrevid = 461091686 | image = Dutasteride.svg | image_class = skin-invert-image | width = 250

<!--Clinical data--> | pronounce = {{IPAc-en|d|u|ˈ|t|æ|s|t|ə|ˌ|r|aɪ|d}}<br />{{respell|doo|TA|stə|RYDE}} | tradename = Avodart, others | Drugs.com = {{drugs.com|monograph|dutasteride}} | MedlinePlus = a603001 | DailyMedID = Dutasteride | pregnancy_category = Not to be used during pregnancy | routes_of_administration = By mouth | class = 5α-Reductase inhibitor | ATC_prefix = G04 | ATC_suffix = CB02 | ATC_supplemental =

| legal_UK = POM | legal_US = Rx-only

<!--Pharmacokinetic data--> | bioavailability = 60%<ref name="LemkeWilliams2008" /> | protein_bound = 99%<ref name="LemkeWilliams2008" /> | metabolism = Liver (CYP3A4)<ref name="LemkeWilliams2008" /> | metabolites = • 4'-Hydroxydutasteride<ref name="LemkeWilliams2008" /><br />• 6'-Hydroxydutasteride<ref name="LemkeWilliams2008" /><br />• 1,2-Dihydrodutasteride<ref name="LemkeWilliams2008" /><br />(All three active)<ref name="LemkeWilliams2008" /> | elimination_half-life = 4–5 weeks<ref name="BurchumRosenthal2014" /><ref name="Blu2008" /> | excretion = Feces: 40% (metabolites)<ref name="LemkeWilliams2008" /><br />Urine: 5% (unchanged)<ref name="LemkeWilliams2008" />

<!--Identifiers--> | CAS_number_Ref = {{cascite|correct|??}} | CAS_number = 164656-23-9 | PubChem = 6918296 | IUPHAR_ligand = 7457 | DrugBank_Ref = {{drugbankcite|correct|drugbank}} | DrugBank = DB01126 | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 5293502 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = O0J6XJN02I | KEGG_Ref = {{keggcite|correct|kegg}} | KEGG = D03820 | ChEBI_Ref = {{ebicite|correct|EBI}} | ChEBI = 521033 | ChEMBL_Ref = {{ebicite|correct|EBI}} | ChEMBL = 1200969 | synonyms = GG-745; GI-198745; GI-198745X; ''N''-[2,5-Bis(trifluoromethyl)phenyl]-3-oxo-4-aza-5α-androst-1-ene-17β-carboxamide

<!--Chemical data--> | IUPAC_name = (1S,3aS,3bS,5aR,9aR,9bS,11aS)-''N''-[2,5-bis(trifluoromethyl)phenyl]-9a,11a-dimethyl-7-oxo-1,2,3,3a,3b,4,5,5a,6,9b,10,11-dodecahydroindeno[5,4-f]quinoline-1-carboxamide | C=27 | H=30 | F=6 | N=2 | O=2 | SMILES = FC(F)(F)c1cc(c(cc1)C(F)(F)F)NC(=O)[C@@H]3[C@]2(CC[C@H]4[C@H]([C@@H]2CC3)CC[C@H]5NC(=O)\C=C/[C@]45C)C | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/C27H30F6N2O2/c1-24-11-9-17-15(4-8-21-25(17,2)12-10-22(36)35-21)16(24)6-7-19(24)23(37)34-20-13-14(26(28,29)30)3-5-18(20)27(31,32)33/h3,5,10,12-13,15-17,19,21H,4,6-9,11H2,1-2H3,(H,34,37)(H,35,36)/t15-,16-,17-,19+,21+,24-,25+/m0/s1 | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = JWJOTENAMICLJG-QWBYCMEYSA-N | density = 1.346 | density_notes= at 294&nbsp;K (calculated)<ref>{{cite journal | vauthors = Łaszcz M, Trzcińska K, Witkowska A, Lipiec-Abramska E, Szczepek WJ | title = Phase transition studies of dutasteride crystalline forms. | journal = CrystEngComm | date = 2015 | volume = 17 | issue = 11 | pages = 2346–2352 | doi = 10.1039/C5CE00036J | bibcode = 2015CEG....17.2346L }}</ref> }}

'''Dutasteride''', sold under the brand name '''Avodart''' among others, is a medication primarily used to treat the symptoms of a benign prostatic hyperplasia (BPH), an enlarged prostate not associated with cancer. A few months may be required before benefits occur.<ref name=BNF76/> It is also used for pattern hair loss in men and as a part of hormone therapy in transgender women.<ref name="ShapiroOtberg2015">{{Cite book |url=https://books.google.com/books?id=bJG9BwAAQBAJ&pg=PA39 |title=Hair Loss and Restoration, Second Edition |vauthors=Shapiro J, Otberg N |date=17 April 2015 |publisher=CRC Press |isbn=978-1-4822-3199-1 |pages=39– |access-date=27 October 2016 |archive-url=https://web.archive.org/web/20230112145741/https://books.google.com/books?id=bJG9BwAAQBAJ&pg=PA39 |archive-date=12 January 2023 |url-status=live}}</ref><ref name="Trans2017">{{cite journal | vauthors = Wesp LM, Deutsch MB | title = Hormonal and Surgical Treatment Options for Transgender Women and Transfeminine Spectrum Persons | journal = The Psychiatric Clinics of North America | volume = 40 | issue = 1 | pages = 99–111 | date = March 2017 | pmid = 28159148 | doi = 10.1016/j.psc.2016.10.006 }}</ref> It is usually taken by mouth.<ref name="AHFS2019">{{Cite web |title=Dutasteride Monograph for Professionals |url=https://www.drugs.com/monograph/dutasteride.html |url-status=live |archive-url=https://web.archive.org/web/20190704111545/https://www.drugs.com/monograph/dutasteride.html |archive-date=4 July 2019 |access-date=18 March 2019 |website=Drugs.com |publisher=American Society of Health-System Pharmacists |language=en}}</ref><ref name="Wu2013">{{cite journal | vauthors = Wu C, Kapoor A | title = Dutasteride for the treatment of benign prostatic hyperplasia | journal = Expert Opinion on Pharmacotherapy | volume = 14 | issue = 10 | pages = 1399–1408 | date = July 2013 | pmid = 23750593 | doi = 10.1517/14656566.2013.797965 | s2cid = 25041466 }}</ref><ref name="BNF76">{{Cite book |title=British National Formulary: BNF 76 |date=2018 |publisher=Pharmaceutical Press |isbn=978-0-85711-338-2 |edition=76 |page=769}}</ref>

<!-- Side effects and mechanism --> The most commonly reported side effects of dutasteride, although rare, include sexual dysfunction. In the largest available study of 6,729 men with BPH, 9% experienced erectile dysfunction (compared to 5.7% treated with a placebo), 3.3% experienced decreased sex drive (vs 1.6% of placebo), and 1.9% had enlarged breasts (vs 1% of placebo).<ref name="Fertig2007DOJ">{{cite journal | vauthors = Fertig RM, Gamret AC, Darwin E, Gaudi S | title = Sexual side effects of 5-α-reductase inhibitors finasteride and dutasteride: A comprehensive review | journal = Dermatology Online Journal | volume = 23 | issue = 11 | date = November 2017 | pmid = 29447628 | doi = 10.5070/D32311037240 | doi-access = free }}</ref><ref name="AndrioleREDUCE2010">{{cite journal | vauthors = 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 | title = Effect of dutasteride on the risk of prostate cancer | journal = The New England Journal of Medicine | volume = 362 | issue = 13 | pages = 1192–1202 | date = April 2010 | pmid = 20357281 | doi = 10.1056/NEJMoa0908127 | doi-access = free }}</ref> Exposure during pregnancy is specifically contraindicated because antiandrogens such as dutasteride have been shown to interfere with the sexual development of male fetuses.<ref name="Blu2008">{{Cite book |url=https://books.google.com/books?id=pHrX2-huQCoC&pg=PA369 |title=Hair Growth and Disorders |vauthors=Blume-Peytavi U, Whiting DA, Trüeb RM |date=26 June 2008 |publisher=Springer Science & Business Media |isbn=978-3-540-46911-7 |pages=182, 369 |access-date=10 December 2016 |archive-url=https://web.archive.org/web/20230110031700/https://books.google.com/books?id=pHrX2-huQCoC&pg=PA369 |archive-date=10 January 2023 |url-status=live}}</ref><ref name=AHFS2019/>

<!-- History, society, and culture --> Dutasteride was patented in 1993 by Glaxo Wellcome (later known as GSK after additional mergers) and was approved for medical use in 2001.<ref name="Fis2006">{{Cite book |url=https://books.google.com/books?id=FjKfqkaKkAAC&pg=PA483 |title=Analogue-based Drug Discovery |vauthors=Fischer J, Ganellin CR |date=2006 |publisher=John Wiley & Sons |isbn=978-3-527-60749-5 |page=483 |language=en |access-date=2020-09-19 |archive-url=https://web.archive.org/web/20230110031701/https://books.google.com/books?id=FjKfqkaKkAAC&pg=PA483 |archive-date=2023-01-10 |url-status=live}}</ref><ref name=AHFS2019/> In the United States and elsewhere, it is available as a generic medication.<ref name=BNF76/> In 2023, it was the 236th most commonly prescribed medication in the US with more than 1{{nbsp}}million prescriptions.<ref>{{Cite web |title=Dutasteride – Drug Usage Statistics |url=https://clincalc.com/DrugStats/Drugs/Dutasteride |url-status=live |archive-url=https://web.archive.org/web/20200206154756/https://clincalc.com/DrugStats/Drugs/Dutasteride |archive-date=6 February 2020 |access-date=7 October 2022 |website=ClinCalc}}</ref>

==Medical uses==

===Benign prostatic hyperplasia and prostate cancer=== Dutasteride is used for treating BPH, colloquially known as an "enlarged prostate".<ref name="Wu2013" /><ref>{{cite journal | vauthors = Slater S, Dumas C, Bubley G | title = Dutasteride for the treatment of prostate-related conditions | journal = Expert Opinion on Drug Safety | volume = 11 | issue = 2 | pages = 325–330 | date = March 2012 | pmid = 22316171 | doi = 10.1517/14740338.2012.658040 | s2cid = 207487490 }}</ref> It is approved by the Food and Drug Administration (FDA) in the U.S. for this indication.<ref name="FDA">{{Cite web |title=Search Results for "DUTASTERIDE" |url=http://www.accessdata.fda.gov/scripts/cder/drugsatfda/index.cfm?fuseaction=Search.Set_Current_Drug&ApplNo=021319&DrugName=AVODART&ActiveIngred=DUTASTERIDE&SponsorApplicant=GLAXOSMITHKLINE&ProductMktStatus=1&goto=Search.DrugDetails |archive-url=https://web.archive.org/web/20210829124132/https://www.accessdata.fda.gov/scripts/cder/daf/ |archive-date=2021-08-29 |access-date=2016-10-29 |website=Drugs@FDA: FDA Approved Drug Products}}</ref> A 2010 Cochrane review found a 25–26% reduction in the risk of developing prostate cancer with 5α-reductase inhibitor chemoprevention.<ref name="pmid20977593">{{cite journal | vauthors = Wilt TJ, Macdonald R, Hagerty K, Schellhammer P, Tacklind J, Somerfield MR, Kramer BS | title = 5-α-Reductase inhibitors for prostate cancer chemoprevention: an updated Cochrane systematic review | journal = BJU International | volume = 106 | issue = 10 | pages = 1444–1451 | date = November 2010 | pmid = 20977593 | doi = 10.1111/j.1464-410X.2010.09714.x | s2cid = 22178061 }}</ref>

===Scalp hair loss and excessive hair growth=== Dutasteride is approved for the treatment of male androgenetic alopecia in South Korea and Japan at a dosage of 0.5&nbsp;mg per day.<ref name="ShapiroOtberg2015" /><ref name="pmid27489426" /> Several studies have found it to induce hair regrowth in men more rapidly and to a greater extent than even the highest approved dosage of finasteride.<ref name="ShapiroOtberg2015" /><ref name="pmid32279398">{{cite journal | vauthors = Dhurat R, Sharma A, Rudnicka L, Kroumpouzos G, Kassir M, Galadari H, Wollina U, Lotti T, Golubovic M, Binic I, Grabbe S, Goldust M | title = 5-Alpha reductase inhibitors in androgenetic alopecia: Shifting paradigms, current concepts, comparative efficacy, and safety | journal = Dermatologic Therapy | volume = 33 | issue = 3 | article-number = e13379 | date = May 2020 | pmid = 32279398 | doi = 10.1111/dth.13379 | s2cid = 215748750 | doi-access = free }}</ref><ref name="pmid30863034">{{cite journal | vauthors = Zhou Z, Song S, Gao Z, Wu J, Ma J, Cui Y | title = The efficacy and safety of dutasteride compared with finasteride in treating men with androgenetic alopecia: a systematic review and meta-analysis | journal = Clinical Interventions in Aging | volume = 14 | pages = 399–406 | date = 2019 | pmid = 30863034 | pmc = 6388756 | doi = 10.2147/CIA.S192435 | doi-access = free }}</ref><ref name="pmid17110217">{{cite journal | vauthors = Olsen EA, Hordinsky M, Whiting D, Stough D, Hobbs S, Ellis ML, Wilson T, Rittmaster RS | title = 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 | journal = Journal of the American Academy of Dermatology | volume = 55 | issue = 6 | pages = 1014–1023 | date = December 2006 | pmid = 17110217 | doi = 10.1016/j.jaad.2006.05.007 }}</ref> The superior effectiveness of dutasteride relative to finasteride for this indication is because the inhibition of 5α-reductase and consequent reduction of dihydrotestosterone (DHT) production within the hair follicles is more complete with dutasteride. Dutasteride is also used off-label in the treatment of female pattern hair loss.<ref name="pmid24017975" /><ref name="CarminaAzziz2019">{{cite journal | vauthors = Carmina E, Azziz R, Bergfeld W, Escobar-Morreale HF, Futterweit W, Huddleston H, Lobo R, Olsen E | title = Female Pattern Hair Loss and Androgen Excess: A Report From the Multidisciplinary Androgen Excess and PCOS Committee | journal = The Journal of Clinical Endocrinology and Metabolism | volume = 104 | issue = 7 | pages = 2875–2891 | date = July 2019 | pmid = 30785992 | doi = 10.1210/jc.2018-02548 | doi-access = free }}</ref>

Other 5α-reductase inhibitors such as finasteride (a type 2 inhibitor) have been used off-label to treat excessive hair growth in women with hirsutism.<ref name="Blu2008" /><ref name="Martin2018">{{cite journal | vauthors = Martin KA, Chang RJ, Ehrmann DA, Ibanez L, Lobo RA, Rosenfield RL, Shapiro J, Montori VM, Swiglo BA | title = Evaluation and treatment of hirsutism in premenopausal women: an endocrine society clinical practice guideline | journal = The Journal of Clinical Endocrinology and Metabolism | volume = 93 | issue = 4 | pages = 1105–1120 | date = April 2008 | pmid = 18252793 | doi = 10.1210/jc.2018-00241 | doi-access = free }}</ref> Since dutasteride is an inhibitor of both type 1 and 2 5α-reductases, it could theoretically be a more effective therapy for hirsutism. However, dutasteride is not recommended for this indication due to a lack of supportive clinical evidence and a substantial risk of birth defects in female patients who inadvertently become pregnant.<ref name="Martin2018" /><ref name="LebwohlHeymann2013">{{Cite book |url=https://books.google.com/books?id=hRryAAAAQBAJ&pg=PA327 |title=Treatment of Skin Disease: Comprehensive Therapeutic Strategies |vauthors=Lebwohl MG, Heymann WR, Berth-Jones J, Coulson I |date=19 September 2013 |publisher=Elsevier Health Sciences |isbn=978-0-7020-5236-1 |pages=327– |access-date=10 December 2016 |archive-url=https://web.archive.org/web/20230112145741/https://books.google.com/books?id=hRryAAAAQBAJ&pg=PA327 |archive-date=12 January 2023 |url-status=live}}</ref>

===Transgender hormone therapy=== Dutasteride is sometimes used as a component of hormone therapy for transgender women in combination with an estrogen and/or another antiandrogen such as spironolactone.<ref name="Trans2017" /> It may be useful for preventing and treating scalp hair loss and can also be used as a general antiandrogen for those who have issues tolerating spironolactone, though as a α-reductase inhibitor it has limited effects compared to AR antagonists.<ref name="Trans2017" />

===Available forms=== Dutasteride is provided in the form of soft, oil-filled gelatin capsules containing 0.5&nbsp;mg dutasteride each.<ref name="FDALabel" />

==Contraindications== Women who are or who may become pregnant should not handle the drug. Dutasteride can cause birth defects in male fetuses, specifically ambiguous genitalia and undermasculinization.<ref name="FDALabel" /><ref name="McVaryWelliver2016">{{Cite book |url=https://books.google.com/books?id=OkLUDAAAQBAJ&pg=PA396 |title=Treatment of Lower Urinary Tract Symptoms and Benign Prostatic Hyperplasia: Current methods, outcomes, and controversies, An Issue of Urologic Clinics of North America, E-Book |vauthors=McVary KT, Welliver C |date=12 August 2016 |publisher=Elsevier Health Sciences |isbn=978-0-323-45994-5 |pages=396– |access-date=10 December 2017 |archive-url=https://web.archive.org/web/20230112145741/https://books.google.com/books?id=OkLUDAAAQBAJ&pg=PA396 |archive-date=12 January 2023 |url-status=live}}</ref> This is due to its antiandrogenic effects similar to what is seen in 5α-reductase deficiency.<ref name="McVaryWelliver2016" /> For the same reason, women who are currently pregnant should never take dutasteride.<ref name="FDALabel" /> People taking dutasteride should not donate blood to prevent birth defects if a pregnant woman receives blood and should also not donate blood for at least 6&nbsp;months after the cessation of treatment due to the drug's long elimination half-life.<ref name="FDALabel"/>

Children and people with known significant hypersensitivity (e.g., serious skin reactions, angioedema) to dutasteride should not take it.<ref name="FDALabel">{{Cite web |last=<!--Staff writer(s); no by-line.--> |date=June 2011 |title=AVODART (dutasteride) Soft Gelatin Capsules Prescribing information |url=https://www.accessdata.fda.gov/drugsatfda_docs/label/2011/021319s023s025lbl.pdf |url-status=live |archive-url=https://web.archive.org/web/20130307020555/http://www.accessdata.fda.gov/drugsatfda_docs/label/2011/021319s023s025lbl.pdf |archive-date=7 March 2013 |access-date=15 September 2013 |website=GlaxoSmithKline |publisher=U.S. Food and Drug Administration}}</ref>

==Adverse effects== Dutasteride has overall been found to be well tolerated in studies of both men and women, producing minimal side effects.<ref name="Hirs2016">{{cite journal | vauthors = Hirshburg JM, Kelsey PA, Therrien CA, Gavino AC, Reichenberg JS | title = Adverse Effects and Safety of 5-alpha Reductase Inhibitors (Finasteride, Dutasteride): A Systematic Review | journal = The Journal of Clinical and Aesthetic Dermatology | volume = 9 | issue = 7 | pages = 56–62 | date = July 2016 | pmid = 27672412 | pmc = 5023004 }}</ref> Adverse effects include headache and gastrointestinal discomfort.<ref name="Hirs2016" /> Isolated reports of menstrual changes, acne, and dizziness also exist.<ref name="Hirs2016" /> A small risk of sexual side effects has been documented in men taking the drug during the first few months of therapy.<ref name="Hirs2016" /><ref name="pmid27784557">{{cite journal | vauthors = Trost L, Saitz TR, Hellstrom WJ | title = Side Effects of 5-Alpha Reductase Inhibitors: A Comprehensive Review | journal = Sexual Medicine Reviews | volume = 1 | issue = 1 | pages = 24–41 | date = May 2013 | pmid = 27784557 | doi = 10.1002/smrj.3 }}</ref>

The FDA added a black-box warning to dutasteride in 2011 describing an increased risk of high-grade prostate cancer in those who take the drug.<ref>{{Cite web |date=18 June 2019 |title=FDA Drug Safety Communication: 5-alpha reductase inhibitors (5-ARIs) may increase the risk of a more serious form of prostate cancer |url=https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-5-alpha-reductase-inhibitors-5-aris-may-increase-risk-more-serious |url-status=live |archive-url=https://web.archive.org/web/20210309192037/https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-5-alpha-reductase-inhibitors-5-aris-may-increase-risk-more-serious |archive-date=9 March 2021 |access-date=9 March 2021 |newspaper=U.S. Food and Drug Administration}}</ref> No direct mechanistic link between 5α-reductase inhibitors and prostate cancer has been established.<ref name="AUAGuideline2021" /> This is not due to a direct link between dutasteride or other 5α-reductase inhibitors and cancer ''per se'', but rather that those who take 5α-reductase inhibitors may have a decrease in prostate-specific antigen (PSA) levels, and therefore increases in PSA (which are an indicator of possible cancer) may be masked in those who take the drug.<ref name="Sarkar2019">{{cite journal | vauthors = Sarkar RR, Parsons JK, Bryant AK, Ryan ST, Kader AK, McKay RR, D'Amico AV, Nguyen PL, Hulley BJ, Einck JP, Mundt AJ, Kane CJ, Murphy JD, Rose BS | title = Association of Treatment With 5α-Reductase Inhibitors With Time to Diagnosis and Mortality in Prostate Cancer | journal = JAMA Internal Medicine | volume = 179 | issue = 6 | pages = 812–819 | date = June 2019 | pmid = 31058923 | pmc = 6503564 | doi = 10.1001/jamainternmed.2019.0280 }}</ref> This is thought to delay cancer diagnosis so that patients taking 5α-reductase inhibitors present with a higher-grade tumor at the time of diagnosis. The American Urological Association <!-- (AUA) --> advises that increased risk for patients taking these drugs leads to higher prostate cancer-specific and all-cause mortality.<ref name="AUAGuideline2021">{{cite journal | vauthors = Lerner LB, McVary KT, Barry MJ, Bixler BR, Dahm P, Das AK, Gandhi MC, Kaplan SA, Kohler TS, Martin L, Parsons JK, Roehrborn CG, Stoffel JT, Welliver C, Wilt TJ | title = Management of Lower Urinary Tract Symptoms Attributed to Benign Prostatic Hyperplasia: AUA GUIDELINE PART I-Initial Work-up and Medical Management | journal = The Journal of Urology | volume = 206 | issue = 4 | pages = 806–817 | date = October 2021 | pmid = 34384237 | doi = 10.1097/JU.0000000000002183 | s2cid = 236999299 }}</ref> The AUA also advises that this effect can be alleviated with more frequent screening and lower PSA cutoffs for diagnostic biopsies in men taking dutasteride or other 5α-reductase inhibitors.<ref name="AUAGuideline2021" /> Dutasteride is known to reduce the growth and prevalence of benign prostate tumors.<ref name="Walsh2010">{{cite journal | vauthors = Walsh PC | title = Chemoprevention of prostate cancer | journal = The New England Journal of Medicine | volume = 362 | issue = 13 | pages = 1237–1238 | date = April 2010 | pmid = 20357287 | doi = 10.1056/NEJMe1001045 }}</ref> A 2018 meta-analysis found no higher risk of breast cancer with 5α-reductase inhibitors.<ref name="pmid29697934">{{cite journal | vauthors = Wang J, Zhao S, Luo L, Li E, Li X, Zhao Z | title = 5-alpha Reductase Inhibitors and risk of male breast cancer: a systematic review and meta-analysis | journal = International Braz J Urol | volume = 44 | issue = 5 | pages = 865–873 | date = 2018 | pmid = 29697934 | pmc = 6237523 | doi = 10.1590/S1677-5538.IBJU.2017.0531 }}</ref>

Sexual and mood side effects, such as erectile dysfunction,<ref name="Fertig2017">{{cite journal | vauthors = Fertig R, Shapiro J, Bergfeld W, Tosti A | title = Investigation of the Plausibility of 5-Alpha-Reductase Inhibitor Syndrome | journal = Skin Appendage Disorders | volume = 2 | issue = 3–4 | pages = 120–129 | date = January 2017 | pmid = 28232919 | pmc = 5264352 | doi = 10.1159/000450617 }}</ref> loss of libido,<ref name="Traish2015">{{cite journal | vauthors = Traish AM, Melcangi RC, Bortolato M, Garcia-Segura LM, Zitzmann M | title = Adverse effects of 5α-reductase inhibitors: What do we know, don't know, and need to know? | journal = Reviews in Endocrine & Metabolic Disorders | volume = 16 | issue = 3 | pages = 177–198 | date = September 2015 | pmid = 26296373 | doi = 10.1007/s11154-015-9319-y | s2cid = 25002351 }}</ref> depression,<ref name="Tra2011">{{cite journal | vauthors = Traish AM, Hassani J, Guay AT, Zitzmann M, Hansen ML | title = Adverse side effects of 5α-reductase inhibitors therapy: persistent diminished libido and erectile dysfunction and depression in a subset of patients | journal = The Journal of Sexual Medicine | volume = 8 | issue = 3 | pages = 872–884 | date = March 2011 | pmid = 21176115 | doi = 10.1111/j.1743-6109.2010.02157.x }}</ref> and reduced semen volume occur in as many as 4.8% of patients taking 5α-reductase inhibitors including dutasteride.<ref name="pmid24955220">{{cite journal | vauthors = Traish AM, Mulgaonkar A, Giordano N | title = The dark side of 5α-reductase inhibitors' therapy: sexual dysfunction, high Gleason grade prostate cancer and depression | journal = Korean Journal of Urology | volume = 55 | issue = 6 | pages = 367–379 | date = June 2014 | pmid = 24955220 | pmc = 4064044 | doi = 10.4111/kju.2014.55.6.367 }}</ref><ref name="Traish2015" /> In affected men, semen volume is decreased an average of 30%,<ref name="Samaplaski 2013">{{cite journal | vauthors = Samplaski MK, Lo K, Grober E, Jarvi K | title = Finasteride use in the male infertility population: effects on semen and hormone parameters | journal = Fertility and Sterility | volume = 100 | issue = 6 | pages = 1542–1546 | date = December 2013 | pmid = 24012200 | doi = 10.1016/j.fertnstert.2013.07.2000 | doi-access = free }}</ref> with a smaller subgroup of patients also experiencing a decrease of sperm motility of 6 to 12%.<ref name="Amory2007">{{cite journal | vauthors = Amory JK, Wang C, Swerdloff RS, Anawalt BD, Matsumoto AM, Bremner WJ, Walker SE, Haberer LJ, Clark RV | title = The effect of 5alpha-reductase inhibition with dutasteride and finasteride on semen parameters and serum hormones in healthy men | journal = The Journal of Clinical Endocrinology and Metabolism | volume = 92 | issue = 5 | pages = 1659–1665 | date = May 2007 | pmid = 17299062 | doi = 10.1210/jc.2006-2203 }}</ref><ref name="Millsop2013" /> Sperm shape and function are unaffected and the impact on male fertility is unknown.<ref name="Semet2017">{{cite journal | vauthors = Semet M, Paci M, Saïas-Magnan J, Metzler-Guillemain C, Boissier R, Lejeune H, Perrin J | title = The impact of drugs on male fertility: a review | journal = Andrology | volume = 5 | issue = 4 | pages = 640–663 | date = July 2017 | pmid = 28622464 | doi = 10.1111/andr.12366 | s2cid = 37989045 | doi-access = free }}</ref> These negative effects reverse by 3–4 months after discontinuation of the drug.<ref name="Semet2017" /><ref name="Millsop2013">{{cite journal | vauthors = Millsop JW, Heller MM, Eliason MJ, Murase JE | title = Dermatological medication effects on male fertility | journal = Dermatologic Therapy | volume = 26 | issue = 4 | pages = 337–346 | date = July 2013 | pmid = 23914891 | doi = 10.1111/dth.12069 | s2cid = 9087715 | doi-access = free }}</ref><ref name="AUAGuideline2021" />

In a study of 6,729 men with benign prostatic hyperplasia (BPH, a condition where the prostate grows unassociated with cancer), 9% had erectile dysfunction (compared to 5.7% treated with a placebo), 3.3% experienced decreased sex drive (vs 1.6% of placebo), and 1.9% had enlarged breasts (vs 1% of placebo).<ref name="Fertig2017" /><ref name="AndrioleREDUCE2010" /> These effects were noted to resolve over time, with many fewer men reporting any adverse effects by the end of the 4-year study.<ref name="AndrioleREDUCE2010" /><ref name="Fertig2017" /> The rate of discontinuation of the drug due to adverse effects was less than 5%.<ref name="AndrioleREDUCE2010" />

A subset of men affected by sexual and mood side effects report persistent loss of libido,<ref name="Fertig2017" /> depression,<ref name="Hirs2016" /> and erectile dysfunction for several years after discontinuing treatment.<ref name="Traish2015" /> This remains a highly contested topic in the academic literature due to disagreements about whether the nocebo effect may play a role,<ref name="ThanRodriguezKhera2018">{{Cite journal |vauthors=Than JK, Rodriguez K, Khera M |date=24 July 2018 |title=Post-finasteride Syndrome: A Review of Current Literature |journal=Current Sexual Health Reports |volume=10 |issue=3 |pages=152–157 |doi=10.1007/s11930-018-0163-4 |issn=1548-3584 |eissn=1548-3592 |s2cid=81968700}}</ref><ref name="SaengmearnuparpLojanapiwatChattipakorn2021">{{cite journal | vauthors = Saengmearnuparp T, Lojanapiwat B, Chattipakorn N, Chattipakorn S | title = The connection of 5-alpha reductase inhibitors to the development of depression | journal = Biomedicine & Pharmacotherapy | volume = 143 | article-number = 112100 | date = November 2021 | pmid = 34479019 | doi = 10.1016/j.biopha.2021.112100 | doi-access = free }}</ref><ref name="Coskuner2019">{{cite journal | vauthors = Coskuner ER, Ozkan B, Culha MG | title = Sexual Problems of Men With Androgenic Alopecia Treated With 5-Alpha Reductase Inhibitors | journal = Sexual Medicine Reviews | volume = 7 | issue = 2 | pages = 277–282 | date = April 2019 | pmid = 30301703 | doi = 10.1016/j.sxmr.2018.07.003 | s2cid = 52946784 }}</ref> whether self-report questionnaires are reliable for this data,<ref name="AUAGuideline2021" /> and whether enough objective evidence exists to conclude these effects are persistent after discontinuation of the drug.<ref name="AUAGuideline2021" /><ref name="Traish 2020">{{cite journal | vauthors = Traish AM | title = Post-finasteride syndrome: a surmountable challenge for clinicians | journal = Fertility and Sterility | volume = 113 | issue = 1 | pages = 21–50 | date = January 2020 | pmid = 32033719 | doi = 10.1016/j.fertnstert.2019.11.030 | s2cid = 211064052 | doi-access = free }}</ref><ref name="Liu2016">{{cite journal | vauthors = Liu L, Zhao S, Li F, Li E, Kang R, Luo L, Luo J, Wan S, Zhao Z | title = Effect of 5α-Reductase Inhibitors on Sexual Function: A Meta-Analysis and Systematic Review of Randomized Controlled Trials | journal = The Journal of Sexual Medicine | volume = 13 | issue = 9 | pages = 1297–1310 | date = September 2016 | pmid = 27475241 | doi = 10.1016/j.jsxm.2016.07.006 }}</ref> The Post-Finasteride Syndrome Foundation (PFSF) was created with a medical advisory board to study the topic (finasteride is a similar 5α-reductase inhibitor)<ref>{{Cite web |title=The Post-Finasteride Syndrome Foundation – Dedicated to supporting research and finding treatments for PFS patients worldwide. |url=https://www.pfsfoundation.org/ |url-status=live |archive-url=https://web.archive.org/web/20211221100527/https://www.pfsfoundation.org/ |archive-date=2021-12-21 |access-date=2021-12-24 |language=en-US}}</ref> and lawsuits alleging harm from the drug are ongoing.<ref>{{Cite news |date=2021-09-08 |title=Group sues to have hair-loss drug Propecia pulled from market |url=https://www.reuters.com/legal/litigation/group-sues-have-hair-loss-drug-propecia-pulled-market-2021-09-08/ |url-status=live |archive-url=https://web.archive.org/web/20211224165809/https://www.reuters.com/legal/litigation/group-sues-have-hair-loss-drug-propecia-pulled-market-2021-09-08/ |archive-date=2021-12-24 |access-date=2021-12-24 |work=Reuters |language=en |vauthors=Pierson B}}</ref> Concerns from the PFSF and other patient advocates led the FDA to add a black-box warning to Finasteride for possible risks of suicide in June 2022.<ref name="AUAGuideline2021" /><ref name="Levine2022Reuters">{{Cite news |date=10 June 2022 |title=FDA requires disclosure of suicide risk for anti-baldness drug |url=https://www.reuters.com/business/healthcare-pharmaceuticals/fda-requires-disclosure-suicide-risk-anti-baldness-drug-2022-06-10/ |url-status=live |archive-url=https://web.archive.org/web/20221112200941/https://www.reuters.com/business/healthcare-pharmaceuticals/fda-requires-disclosure-suicide-risk-anti-baldness-drug-2022-06-10/ |archive-date=12 November 2022 |access-date=12 November 2022 |work=Reuters |language=en |vauthors=Levine D}}</ref> Some experts have questioned the basis of the black-box warning, given that it relies on anecdotal patient-reported outcomes rather than prospective trials.<ref name="AUAGuideline2021" /> Indeed, a 2024 meta analysis of more than 2.2 million patients suggested no causal link between the drug and neurological side effects <ref>https://pubmed.ncbi.nlm.nih.gov/38692949/ </ref>

==Overdose== No specific antidote for overdose of dutasteride is known, since the drug is extremely safe and well tolerated. Research studies show that even at 100 times the normal dose, dutasteride is not lethal.<ref name="Avodart-Label">{{Cite web |title=AVODART (dutasteride) Soft Gelatin Capsules Prescribing information |url=https://www.accessdata.fda.gov/drugsatfda_docs/label/2013/021319s028s029lbl.pdf |url-status=live |archive-url=https://web.archive.org/web/20210403220821/https://www.accessdata.fda.gov/drugsatfda_docs/label/2013/021319s028s029lbl.pdf |archive-date=2021-04-03 |access-date=2020-01-10 |website=GlaxoSmithKline |publisher=U.S. Food and Drug Administration}}</ref> Treatment of dutasteride overdose should be based on symptoms and should be with supportive therapies.<ref name="Avodart-Label" /> The long elimination half-life of dutasteride should be taken into consideration in the event of an overdose of the medication.<ref name="Avodart-Label" /> Dutasteride has been used in clinical studies at doses of up to 40&nbsp;mg/day for a week (80&nbsp;times the therapeutic dosage) and 5&nbsp;mg/day for 6&nbsp;months (10&nbsp;times the therapeutic dosage) with no significant safety concerns or additional side effects.<ref name="Avodart-Label" />

== Current investigations == Dutasteride has been studied in combination with bicalutamide in the treatment of prostate cancer.<ref name="pmid26048455">{{cite journal | vauthors = Chu FM, Sartor O, Gomella L, Rudo T, Somerville MC, Hereghty B, Manyak MJ | title = A randomised, double-blind study comparing the addition of bicalutamide with or without dutasteride to GnRH analogue therapy in men with non-metastatic castrate-resistant prostate cancer | journal = European Journal of Cancer | volume = 51 | issue = 12 | pages = 1555–1569 | date = August 2015 | pmid = 26048455 | doi = 10.1016/j.ejca.2015.04.028 }}</ref><ref name="pmid26702991">{{cite journal | vauthors = Gaudet M, Vigneault É, Foster W, Meyer F, Martin AG | title = Randomized non-inferiority trial of Bicalutamide and Dutasteride versus LHRH agonists for prostate volume reduction prior to I-125 permanent implant brachytherapy for prostate cancer | journal = Radiotherapy and Oncology | volume = 118 | issue = 1 | pages = 141–147 | date = January 2016 | pmid = 26702991 | doi = 10.1016/j.radonc.2015.11.022 }}</ref><ref name="pmid27330919">{{cite journal | vauthors = Dijkstra S, Witjes WP, Roos EP, Vijverberg PL, Geboers AD, Bruins JL, Smits GA, Vergunst H, Mulders PF | title = The AVOCAT study: Bicalutamide monotherapy versus combined bicalutamide plus dutasteride therapy for patients with locally advanced or metastatic carcinoma of the prostate-a long-term follow-up comparison and quality of life analysis | journal = SpringerPlus | volume = 5 | page = 653 | year = 2016 | pmid = 27330919 | pmc = 4870485 | doi = 10.1186/s40064-016-2280-8 | doi-access = free | article-number = 653 }}</ref>

Ongoing clinical trials are investigating whether dutasteride may be an effective treatment for premenstrual dysphoric disorder (PMDD), because dutasteride may inhibit the conversion of progesterone to allopregnanolone, a neurosteroid metabolite, which may be responsible for some of the debilitating symptoms of PMDD.<ref name="pmid26766596">{{cite journal | vauthors = Pearlstein T | title = Treatment of Premenstrual Dysphoric Disorder: Therapeutic Challenges | journal = Expert Review of Clinical Pharmacology | volume = 9 | issue = 4 | pages = 493–496 | date = April 2016 | pmid = 26766596 | doi = 10.1586/17512433.2016.1142371 | quote = A recent study with a 5α-reductase inhibitor dutasteride, that blocks the conversion of progesterone to ALLO, reported that dutasteride 2.5 mg daily decreased several premenstrual symptoms | doi-access = free }}</ref><ref name="PsychBullNaguy2022">{{cite journal | vauthors = Naguy A, El-Sheshai A, Thiguti SH, Alamiri B | title = Psychopharmacotherapy of Premenstrual Dysphoric Disorder-''New Vistas'' | journal = Psychopharmacology Bulletin | volume = 52 | issue = 3 | pages = 81–83 | date = 2025 | doi = 10.64719/pb.4447 | pmid = 35815174 | pmc = 9235312 | quote = Capitalizing on this premise, agents in the pipeline for PMDD including dutasteride, ulipristal acetate, and sepranolone are promising. Dutasteride, FDA-approved for benign prostatic hyperplasia, is a 5-α reductase inhibitor; the latter catalyzes the rate-limiting step in metabolism of progesterone to allopregnanolone...Two double-blind RCTs, cross-over trials, support use of dutasteride where high-dose (2.5 mg/d) outperforms placebo. }}</ref>

==Pharmacology==

===Pharmacodynamics=== Dutasteride belongs to a class of drugs called 5α-reductase inhibitors, which block the action of the 5α-reductase enzymes that convert testosterone into DHT.<ref name="BostwickCheng2014">{{Cite book |url=https://books.google.com/books?id=wrHQAgAAQBAJ&pg=PA492 |title=Urologic Surgical Pathology |vauthors=Bostwick DG, Cheng L |date=24 January 2014 |publisher=Elsevier Health Sciences |isbn=978-0-323-08619-6 |pages=492–}}</ref> It inhibits all three forms of 5α-reductase, and can decrease DHT levels in the blood by up to 98%.<ref name="LemkeWilliams2008">{{Cite book |url=https://books.google.com/books?id=R0W1ErpsQpkC&pg=PA1286 |title=Foye's Principles of Medicinal Chemistry |vauthors=Lemke TL, Williams DA |publisher=Lippincott Williams & Wilkins |year=2008 |isbn=978-0-7817-6879-5 |pages=1286–1287 |access-date=2017-12-06 |archive-url=https://web.archive.org/web/20230110031700/https://books.google.com/books?id=R0W1ErpsQpkC&pg=PA1286 |archive-date=2023-01-10 |url-status=live}}</ref><ref name="Yamana2010">{{cite journal | vauthors = Yamana K, Labrie F, Luu-The V | title = Human type 3 5α-reductase is expressed in peripheral tissues at higher levels than types 1 and 2 and its activity is potently inhibited by finasteride and dutasteride | journal = Hormone Molecular Biology and Clinical Investigation | volume = 2 | issue = 3 | pages = 293–299 | date = August 2010 | pmid = 25961201 | doi = 10.1515/hmbci.2010.035 | s2cid = 28841145 }}</ref><ref name="Bradbury2007">{{Cite book |url=https://books.google.com/books?id=fdtDAAAAQBAJ&pg=PA49 |title=Cancer |vauthors=Bradbury R |date=30 January 2007 |publisher=Springer Science & Business Media |isbn=978-3-540-33120-9 |pages=49–}}</ref> Specifically it is a competitive, mechanism-based (irreversible) inhibitor of all three isoforms of 5α-reductase, types I, II, and III ({{abbrlink|IC<sub>50</sub>|Half-maximal inhibitory concentration}} values are 3.9&nbsp;nM for type I and 1.8&nbsp;nM for type II).<ref name="LemkeWilliams2008" /><ref name="Yamana2010" /><ref name="pmid18318566">{{cite journal | vauthors = Keam SJ, Scott LJ | title = Dutasteride: a review of its use in the management of prostate disorders | journal = Drugs | volume = 68 | issue = 4 | pages = 463–485 | year = 2008 | pmid = 18318566 | doi = 10.2165/00003495-200868040-00008 | s2cid = 242987808 }}</ref><ref name="pmid9871428">{{cite journal | vauthors = Gisleskog PO, Hermann D, Hammarlund-Udenaes M, Karlsson MO | title = A model for the turnover of dihydrotestosterone in the presence of the irreversible 5 alpha-reductase inhibitors GI198745 and finasteride | journal = Clinical Pharmacology and Therapeutics | volume = 64 | issue = 6 | pages = 636–647 | date = December 1998 | pmid = 9871428 | doi = 10.1016/S0009-9236(98)90054-6 | s2cid = 42901328 }}</ref> This is in contrast to finasteride, which is similarly an irreversible inhibitor of 5α-reductase but only inhibits the type II and III isoenzymes.<ref name="pmid9871428" /><ref name="KeserüSwinney2015">{{Cite book |url=https://books.google.com/books?id=7WpICgAAQBAJ&pg=PA165 |title=Thermodynamics and Kinetics of Drug Binding |vauthors=Keserü G, Swinney DC |date=28 July 2015 |publisher=Wiley |isbn=978-3-527-67304-9 |pages=165–}}</ref><ref name="Yamana2010" /> As a result of this difference, dutasteride is able to achieve a reduction in circulating DHT levels of up to 98%, whereas finasteride is able to achieve a reduction of only 65 to 70%.<ref name="Bradbury2007" /><ref name="BurchumRosenthal2014" /><ref name="BostwickCheng2014" /><ref name="HeesakkersChapple2016">{{Cite book |url=https://books.google.com/books?id=aWKhCwAAQBAJ&pg=PA280 |title=Practical Functional Urology |vauthors=Heesakkers J, Chapple C, De Ridder D, Farag F |date=24 February 2016 |publisher=Springer |isbn=978-3-319-25430-2 |pages=280–}}</ref> In spite of the differential reduction in circulating DHT levels, the two drugs decrease levels of DHT to a similar extent of approximately 85 to 90% in the prostate gland,<ref name="HeesakkersChapple2016" /> where the type II isoform predominates.<ref name="pmid18318566" />

Since 5α-reductases degrade testosterone to DHT, the inhibition of these enzymes could theoretically cause an increase in testosterone. A 2018 review found that initiation of 5α-reductase inhibitors did not result in a consistent increase in testosterone levels.<ref name="Traish2019">{{cite journal | vauthors = Traish AM, Krakowsky Y, Doros G, Morgentaler A | title = Do 5α-Reductase Inhibitors Raise Circulating Serum Testosterone Levels? A Comprehensive Review and Meta-Analysis to Explaining Paradoxical Results | journal = Sexual Medicine Reviews | volume = 7 | issue = 1 | pages = 95–114 | date = January 2019 | pmid = 30098986 | doi = 10.1016/j.sxmr.2018.06.002 | s2cid = 51968365 }}</ref> Among the studies analyzed, there was no statistically significant change in testosterone levels from 5α-reductase inhibitors overall, though men with lower baseline testosterone levels did show an increase.<ref name="Traish2019" />

In addition to inhibition of DHT production, 5α-reductase inhibitors such as dutasteride are also neurosteroidogenesis inhibitors, preventing the 5α-reductase-mediated biosynthesis of various neurosteroids, including allopregnanolone (from progesterone), {{abbrlink|THDOC|tetrahydrodeoxycorticosterone}} (from deoxycorticosterone), and 3α-androstanediol (from testosterone).<ref name="pmid24955220" /> These neurosteroids are potent positive allosteric modulators of the GABA<sub>A</sub> receptor and have shown antidepressant, anxiolytic, and pro-sexual effects in animal research.<ref name="pmid24955220" /><ref name="Weizman2008">{{Cite book |url=https://books.google.com/books?id=uABKkFdPjhkC |title=Neuroactive Steroids in Brain Function, Behavior and Neuropsychiatric Disorders: Novel Strategies for Research and Treatment |vauthors=Weizman A |date=1 February 2008 |publisher=Springer Science & Business Media |isbn=978-1-4020-6854-6}}</ref><ref name="TvrdeićPoljak2016">{{Cite journal |vauthors=Tvrdeić A, Poljak L |year=2016 |title=Neurosteroids, GABAA receptors and neurosteroid based drugs: are we witnessing the dawn of the new psychiatric drugs? |journal=Endocrine Oncology and Metabolism |volume=2 |issue=1 |pages=60–71 |doi=10.21040/eom/2016.2.7 |doi-broken-date=12 July 2025 |doi-access=free}}</ref> For this reason, decreased neurosteroid production is one hypothesized mechanism for sexual dysfunction and depression associated with 5α-reductase inhibitors such as dutasteride.<ref name="pmid24955220" />

===Pharmacokinetics=== The oral bioavailability of dutasteride is about 60%.<ref name="LemkeWilliams2008" /> Consumption with food does not adversely affect its absorption.<ref name="LemkeWilliams2008" /> Peak plasma levels occur 2 to 3&nbsp;hours after administration.<ref name="LemkeWilliams2008" /> Dutasteride is present in semen at levels up to 3&nbsp;ng/ml, with no significant effects on DHT levels of sexual partners.<ref name="LemkeWilliams2008" /> The drug is extensively metabolized in the liver by ''CYP3A4''.<ref name="LemkeWilliams2008" /> It has three major metabolites: 6'-hydroxydutasteride, 4'-hydroxydutasteride, and 1,2-dihydrodutasteride. The former two are formed by ''CYP3A4'', while the latter is not.<ref name="LemkeWilliams2008" /> All three metabolites are active; 6'-hydroxydutasteride has similar 5α-reductase inhibitor potency as dutasteride, while the other two are less potent.<ref name="LemkeWilliams2008" /> Dutasteride has an extremely long terminal or elimination half-life of about 4 to 5&nbsp;weeks.<ref name="BurchumRosenthal2014">{{Cite book |url=https://books.google.com/books?id=C7_NBQAAQBAJ&pg=PA803 |title=Lehne's Pharmacology for Nursing Care |vauthors=Burchum J, Rosenthal L |date=2 December 2014 |publisher=Elsevier Health Sciences |isbn=978-0-323-34026-7 |pages=803– |access-date=27 October 2016 |archive-url=https://web.archive.org/web/20230112145742/https://books.google.com/books?id=C7_NBQAAQBAJ&pg=PA803 |archive-date=12 January 2023 |url-status=live}}</ref><ref name="Blu2008" /> Its elimination half-life is increased in the elderly (170&nbsp;hours for men aged 20–49&nbsp;years, 300&nbsp;hours for men aged >70&nbsp;years).<ref name="LemkeWilliams2008" /> No dosage adjustment is necessary in the elderly nor in patients with renal impairment.<ref name="LemkeWilliams2008" /> Because of its long elimination half-life, dutasteride requires 5 to 6&nbsp;months to reach steady-state concentrations.<ref name="pmid18318566" /> It also remains in the body for a long time after discontinuation and can be detected up to 4 to 6&nbsp;months.<ref name="LemkeWilliams2008" /><ref name="BurchumRosenthal2014" /> In contrast to dutasteride, finasteride has a short terminal half-life of only 5 to 8&nbsp;hours.<ref name="Blu2008" /><ref name="LemkeWilliams2008" /> Dutasteride is eliminated mainly in the feces (40%) as metabolites.<ref name="LemkeWilliams2008" /> A smaller portion (5%) is eliminated unchanged in the urine.<ref name="LemkeWilliams2008" />

==Chemistry== {{See also|List of 5α-reductase inhibitors}}

Dutasteride, also known as ''N''-[2,5-bis(trifluoromethyl)phenyl]-3-oxo-4-aza-5α-androst-1-ene-17β-carboxamide, is a synthetic androstane steroid and a 4-azasteroid.<ref name="LemkeWilliams2012">{{Cite book |url=https://books.google.com/books?id=Sd6ot9ul-bUC&pg=PA1381 |title=Foye's Principles of Medicinal Chemistry |vauthors=Lemke TL, Williams DA |date=24 January 2012 |publisher=Lippincott Williams & Wilkins |isbn=978-1-60913-345-0 |pages=1381–}}</ref><ref name="Ravina2011">{{Cite book |url=https://books.google.com/books?id=iDNy0XxGqT8C&pg=PA183 |title=The Evolution of Drug Discovery: From Traditional Medicines to Modern Drugs |vauthors=Ravina E |date=11 January 2011 |publisher=John Wiley & Sons |isbn=978-3-527-32669-3 |pages=183–}}</ref> It is an analogue of finasteride in which the ''tert''-butyl amide moiety has been replaced with a 2,5-''bis''(trifluoromethyl)phenyl group.<ref name="Ravina2011" />

==History== Dutasteride was patented in 1996 and was first described in the scientific literature in 1997.<ref name="Drugs.com" /><ref name="Llewellyn2011" /> It was approved by the FDA for the treatment of BPH in November 2001, and was introduced on the United States market the following year under the brand name Avodart.<ref name="Llewellyn2011" /> Dutasteride has subsequently been introduced in many other countries, including throughout Europe and South America.<ref name="Llewellyn2011">{{Cite book |url=https://books.google.com/books?id=afKLA-6wW0oC&pg=PT971 |title=Anabolics |vauthors=Llewellyn W |publisher=Molecular Nutrition Llc |year=2011 |isbn=978-0-9828280-1-4 |pages=968–,971– |access-date=2017-12-11 |archive-url=https://web.archive.org/web/20230112145743/https://books.google.com/books?id=afKLA-6wW0oC&pg=PT971 |archive-date=2023-01-12 |url-status=live}}</ref> The patent protection of dutasteride expired in November 2015, so the drug has since become available in the United States in a variety of low-cost generic formulations.<ref name="Drugs.com">{{Cite web |title=Generic Avodart Availability |url=https://www.drugs.com/availability/generic-avodart.html |url-status=live |archive-url=https://web.archive.org/web/20161220231141/https://www.drugs.com/availability/generic-avodart.html |archive-date=2016-12-20 |access-date=2016-12-10 |website=Drugs.com}}</ref>

It was approved for the treatment of scalp hair loss in South Korea in 2009 and in Japan in 2015.<ref>{{Cite web |date=3 December 2015 |title=GSK Japan delays alopecia drug launch after Catalent manufacturing halt |url=http://www.in-pharmatechnologist.com/Regulatory-Safety/GSK-Japan-delays-alopecia-drug-launch-after-Catalent-manufacturing-halt |url-status=live |archive-url=https://web.archive.org/web/20161001165059/http://www.in-pharmatechnologist.com/Regulatory-Safety/GSK-Japan-delays-alopecia-drug-launch-after-Catalent-manufacturing-halt |archive-date=1 October 2016 |access-date=14 June 2017 |vauthors=MacDonald G}}</ref> It has not been approved for this indication in the United States,<ref name="ShapiroOtberg2015" /><ref name="pmid27489426">{{cite journal | vauthors = Choi GS, Kim JH, Oh SY, Park JM, Hong JS, Lee YS, Lee WS | title = Safety and Tolerability of the Dual 5-Alpha Reductase Inhibitor Dutasteride in the Treatment of Androgenetic Alopecia | journal = Annals of Dermatology | volume = 28 | issue = 4 | pages = 444–450 | date = August 2016 | pmid = 27489426 | pmc = 4969473 | doi = 10.5021/ad.2016.28.4.444 }}</ref> though it is often used off-label both orally and topically.<ref name="pmid24017975">{{cite journal | vauthors = Nusbaum AG, Rose PT, Nusbaum BP | title = Nonsurgical therapy for hair loss | journal = Facial Plastic Surgery Clinics of North America | volume = 21 | issue = 3 | pages = 335–342 | date = August 2013 | pmid = 24017975 | doi = 10.1016/j.fsc.2013.04.003 }}</ref><ref>{{cite journal | vauthors = Andrade JF, Verbinnen A, Bakst A, Cunha-Filho M, Gelfuso GM, Gratieri T | title = Topical dutasteride for androgenic alopecia: current state and prospects | journal = Therapeutic Delivery | volume = 16 | issue = 3 | pages = 271–283 | date = March 2025 | pmid = 39641480 | doi = 10.1080/20415990.2024.2437973 | pmc = 11875473 }}</ref>

==Society and culture== thumb|200px|right|Avodart (dutasteride) 500 μg soft capsules

===Generic names=== Dutasteride is the generic name of the drug Avodart and its international nonproprietary name, United States Adopted Name, British Approved Name, and Japanese Accepted Name.<ref name="Drugs.com-2">{{Cite web |title=Dutasteride |url=https://www.drugs.com/international/dutasteride.html |url-status=live |archive-url=https://web.archive.org/web/20171211105304/https://www.drugs.com/international/dutasteride.html |archive-date=2017-12-11 |access-date=2017-12-11 |website=Drugs.com}}</ref>

===Brand names=== Dutasteride is sold primarily under the brand name Avodart, but also in combination with tamsulosin under the brand names Combodart, Duodart, and Jalyn.<ref name="Drugs.com-2" /> Dutasteride is also available in India in combination with alfuzosin under the brand names Alfusin-D and Dutalfa.<ref name="Drugs.com-2" />

===Availability=== Dutasteride is available widely throughout the world, including in the United States, Canada, the United Kingdom, Ireland, Europe, Australia, South Africa, Latin America, Asia, and elsewhere.<ref name="Drugs.com-2" /> It is available as a generic medication in many countries, including the United States.<ref name="Drugs.com" />

== References == {{Reflist}}

== Further reading == {{refbegin}} * {{cite journal | vauthors = Frye SV | title = Discovery and clinical development of dutasteride, a potent dual 5alpha-reductase inhibitor | journal = Current Topics in Medicinal Chemistry | volume = 6 | issue = 5 | pages = 405–421 | year = 2006 | pmid = 16719800 | doi = 10.2174/156802606776743101 }} {{refend}}

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