finasteride (Proscar, Propecia)
Jump to navigation
Jump to search
Introduction
Tradenames: Proscar, Propecia.
Indications
- benign prostatic hypertrophy (BPH)
- 5 mg PO QD
- induces regression of hyperplastic prostate tissue
- 2-6 months may be required before improvement of symptoms
- combination therapy finasteride + alpha blocker is no better than either agent alone
- efficacy in treatment of BPH generally confined to patients with a large prostate (40 mL)[4][6]
- used in combination with other androgen antagonists for prostate cancer
- lowers 7 year risk of prostate cancer 25%[11]
- statistically insignificant decline in prostate cancer mortality[11]
- hair growth/prevention of hair loss (androgenic alopecia)
- 1 mg PO QD
- 3-12 months before benefits seen
- may be inferior to dutasteride
- hirsuitism
Contraindications
- pregnancy
- prostate cancer prophylaxis
- see finasteride prophylaxis study
- although finasteride lowers serum PSA by as much as 50%, it does not diminish risk of prostate cancer[6]
- not useful for urge incontinence associated with benign prostatic hypertrophy
Dosage
Tabs: 1 & 5 mg.
Pharmacokinetics
- oral bioavailability is 64%, unaffected by food
- metabolized by liver by cyt P450 3A4 to inactive compounds
- metabolites excreted mainly in the bile
elimination via liver
Adverse effects
- impotence, erectile dysfunction (common[4])
- decreased libido may persist after discontinuation[7][8][12]
- decreased volume of ejaculate
- breast swelling
- hypersensitivity
- not a risk factor for high-grade prostate cancer[10]
- depression, anxiety, suicide ideation[13]
- men seeking treatment for alopecia have a higher prevalence of depression & sexual dysfunction than the general population,
- FDA requires addition of suicidal ideation & behavior to adverse effects[13]
Drug interactions
- any drug that inhibits cyt P450 3A4 may increase levels of finasteride
- any drug that induces cyt P450 3A4 may diminish levels of finasteride
Test interactions
- lowers prostate-specific antigen in serum (PSA)
Laboratory
Mechanism of action
- inhibits testosterone 5-alpha reductase 2 which converts testosterone to dihydrotestosterone (DHT)
- DHT is responsible for stimulation of prostatic growth
- decreases prostate size (after several months)
- diminishes risk of prostate cancer[5]
Clinical trials
- Proscar Long-Term Efficacy and Safety Study (PLESS)
More general terms
Additional terms
Component of
References
- ↑ The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996
- ↑ http/www.propecia.com
- ↑ Drug Information & Medication Formulary, Veterans Affairs, Central California Health Care System, 1st ed., Ravnan et al eds, 1998
- ↑ 4.0 4.1 4.2 Medical Knowledge Self Assessment Program (MKSAP) 11, 17, 18, 19. American College of Physicians, Philadelphia 1998, 2015, 2018, 2022.
- ↑ 5.0 5.1 Prescriber's Letter 15(8): 2008 Finasteride (Proscar) Reduces Prostate Cancer Risk Detail-Document#: http://prescribersletter.com/(5bhgn1a4ni4cyp2tvybwfh55)/pl/ArticleDD.aspx?li=1&st=1&cs=&s=PRL&pt=3&fpt=25&dd=240807&pb=PRL (subscription needed) http://www.prescribersletter.com
- ↑ 6.0 6.1 6.2 Geriatric Review Syllabus, 7th edition Parada JT et al (eds) American Geriatrics Society, 2010
Geriatric Review Syllabus, 8th edition (GRS8) Durso SC and Sullivan GN (eds) American Geriatrics Society, 2013 - ↑ 7.0 7.1 FDA: Questions and Answers: Finasteride Label Changes http://www.fda.gov/Drugs/DrugSafety/InformationbyDrugClass/ucm299754.htm
- ↑ 8.0 8.1 Prescriber's Letter 19(9): 2012 Finasteride (Propecia, Proscar) and Persistent Sexual Adverse Events Detail-Document#: http://prescribersletter.com/(5bhgn1a4ni4cyp2tvybwfh55)/pl/ArticleDD.aspx?li=1&st=1&cs=&s=PRL&pt=3&fpt=25&dd=280923&pb=PRL (subscription needed) http://www.prescribersletter.com
Prescriber's Letter 20(3): 2013 Persistent Sexual Dysfunction with Finasteride and Dutasteride Detail-Document#: http://prescribersletter.com/(5bhgn1a4ni4cyp2tvybwfh55)/pl/ArticleDD.aspx?li=1&st=1&cs=&s=PRL&pt=3&fpt=25&dd=290308&pb=PRL (subscription needed) http://www.prescribersletter.com - ↑ Thompson IM Long-Term Survival of Participants in the Prostate Cancer Prevention Trial. N Engl J Med 2013; 369:603-610 <PubMed> PMID: https://www.ncbi.nlm.nih.gov/pubmed/23944298 <Internet> http://www.nejm.org/doi/full/10.1056/NEJMoa1215932
LeFevre M A Role for Finasteride in the Prevention of Prostate Cancer? N Engl J Med 2013; 369:670-671August 15, 2013 <PubMed> PMID: https://www.ncbi.nlm.nih.gov/pubmed/23944306 <Internet> http://www.nejm.org/doi/full/10.1056/NEJMe1307059 - ↑ 10.0 10.1 Unger JM, Hershman DL, Till C et al. Using Medicare claims to examine long-term prostate cancer risk of finasteride in the Prostate Cancer Prevention Trial. J Natl Cancer Inst 2018 Nov; 110:1208-1215. PMID: https://www.ncbi.nlm.nih.gov/pubmed/29534197
- ↑ 11.0 11.1 11.2 Goodman PJ, Tangen CM, Darke AK et al Long-Term Effects of Finasteride on Prostate Cancer Mortality. N Engl J Med 2019; 380:393-394 PMID: https://www.ncbi.nlm.nih.gov/pubmed/30673548 https://www.nejm.org/doi/full/10.1056/NEJMc1809961
- ↑ 12.0 12.1 Ho RS Ongoing Concerns Regarding Finasteride for the Treatment of Male-Pattern Androgenetic Alopecia. JAMA Dermatol. Published online November 11, 2020 PMID: https://www.ncbi.nlm.nih.gov/pubmed/33175098 https://jamanetwork.com/journals/jamadermatology/fullarticle/2772815
- ↑ 13.0 13.1 13.2 Kneisel K Renewed Concerns About Finasteride and Mental Health
Database study links popular alopecia treatment with increased risks of suicidality, depression. MedPage Today 2020-11-27 https://www.medpagetoday.org/dermatology/generaldermatology/89913
Nguyen DD, et al Investigation of suicidality and psychological adverse events in patients treated with finasteride. JAMA Dermatol 2020. Nov 11 PMID: https://www.ncbi.nlm.nih.gov/pubmed/33175100 PMCID: PMC7658800 https://jamanetwork.com/journals/jamadermatology/article-abstract/2772818
Ho RS Ongoing Concerns Regarding Finasteride for the Treatment of Male-Pattern Androgenetic Alopecia. JAMA Dermatol. Published online November 11, 2020. PMID: https://www.ncbi.nlm.nih.gov/pubmed/33175098 https://jamanetwork.com/journals/jamadermatology/article-abstract/2772815
Levine D FDA Requires Disclosure of Suicide Risk for Anti-baldness Drug. Medscape. June 24, 2022 https://www.medscape.com/viewarticle/975401