II. Indications
-
Benign Prostatic Hyperplasia
- BPH-Associated Gross Hematuria
- Large Prostate size >40 ml (see PSA to estimate Prostate size)
-
Androgenic Alopecia in males (Finasteride)
- Adjunct to hair Transplantation
III. Mechanism
- Inhibits Testosterone to Dihydrotestosterone conversion
- Competitive Inhibition of enzyme 5a-reductase
- Finasteride inhibits Type II 5a reductase
- Dutasteride inhibits both Type I and II 5a reductase
- Reduces volume of Prostate
- Improves urine Blood Flow
IV. Preparations
- Finasteride (Propecia, Proscar)
- Dutasteride (Avodart)
V. Dosing
-
Alopecia
- Finasteride 1 mg orally daily (or one quarter tablet daily of the 5 mg tablet)
-
Benign Prostatic Hyperplasia (typically used in combination with Tamsulosin or Terazosin)
- Finasteride 5 mg orally daily
- Dutasteride 0.5 mg orally daily
VI. Advantages: Finasteride
-
Alopecia
- Increases Hair Growth and reduces Hair Loss
- Effective on vertex and anterior mid-scalp
- Side effects uncommon
-
Benign Prostatic Hyperplasia
- May be more effective in men with large Prostate
VII. Disadvantages: Finasteride
-
Alopecia
- Improvements take 6-12 months
- Any benefits are lost when medication is stopped
- Finasteride 1 mg tablet is much more expensive then 5 mg tablet
- Consider quartering the 5 mg tablet (generic, cheap) which drops the cost considerably
-
Benign Prostatic Hyperplasia
- Increased urine flow not evident for 6-12 months
- Mediocre effects on obstructive symptoms and urine flow (better in Prostate size >40 ml)
- Less effective than alpha blockers (e.g. Hytrin)
- Less effective than surgery
- Only as effective as Saw Palmetto
- Highly effective in reducing BPH-related Gross Hematuria (80%)
VIII. Adverse Effects
- Suicidal Ideation
- Decreased Libido or Erectile Dysfunction (2%)
- Longterm Erectile Dysfunction may persists even after stopping Finasteride in up to 0.1% of patients
- Irwig (2012) J Sex Med 9(11): 2927-32 [PubMed]
- Lowers Prostate Specific Antigen (PSA) Values by 30-50%
- Obtain PSA baseline prior to starting Finasteride
- Double the actual PSA to determine work-up
- Obtain baseline Digital Rectal Exam
- Longterm use associated with high grade Prostate Cancer
Images: Related links to external sites (from Bing)
Related Studies
finasteride (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
FINASTERIDE 1 MG TABLET | Generic | $0.04 each |
FINASTERIDE 5 MG TABLET | Generic | $0.06 each |
propecia (on 10/19/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
PROPECIA 1 MG TABLET | Generic | $0.04 each |
dutasteride (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
DUTASTERIDE 0.5 MG CAPSULE | Generic | $0.19 each |
DUTASTERIDE-TAMSULOSIN 0.5-0.4 | Generic | $2.02 each |
avodart (on 11/4/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
AVODART 0.5 MG SOFTGEL | Generic | $0.19 each |
Ontology: Finasteride (C0060389)
Definition (MSH) | An orally active 3-OXO-5-ALPHA-STEROID 4-DEHYDROGENASE inhibitor. It is used as a surgical alternative for treatment of benign PROSTATIC HYPERPLASIA. |
Definition (NCI) | A synthetic 4-azasteroid compound. Finasteride competitively binds to and inhibits steroid type II 5-alpha-reductase in the prostate gland, liver, and skin, thereby interfering with the enzymatic conversion of testosterone to 5-dihydrotestosterone (DHT) and reducing serum DHT levels. The reduction in serum DHT levels results in diminished stimulation of androgen receptors in the nuclei of prostate cells and, so, diminished prostate cell proliferation. |
Definition (NCI_NCI-GLOSS) | A drug used to reduce the amount of male hormone (testosterone) produced by the body. |
Definition (CSP) | orally active testosterone 5-alpha reductase inhibitor, used as an alternative to surgery for treatment of benign prostatic hyperplasia. |
Definition (PDQ) | A synthetic 4-azasteroid compound. Finasteride competitively binds to and inhibits steroid type II 5-alpha-reductase in the prostate gland, liver, and skin, thereby interfering with the enzymatic conversion of testosterone to 5-dihydrotestosterone (DHT) and reducing serum DHT levels. The reduction in serum DHT levels results in diminished stimulation of androgen receptors in the nuclei of prostate cells and, so, diminished prostate cell proliferation. Check for "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=41096&idtype=1" active clinical trials or "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=41096&idtype=1&closed=1" closed clinical trials using this agent. ("http://nciterms.nci.nih.gov:80/NCIBrowser/ConceptReport.jsp?dictionary=NCI_Thesaurus&code=C1099" NCI Thesaurus) |
Concepts | Hormone (T125) , Pharmacologic Substance (T121) , Steroid (T110) |
MSH | D018120 |
SnomedCT | 109035006, 386963006 |
LNC | LP101034-9, MTHU036233 |
English | Finasteride, 4-Azaandrost-1-ene-17-carboxamide, N-(1,1-dimethylethyl)-3-oxo-, (5alpha,17beta)-, (5alpha,17beta)-N-(1,1-Dimethylethyl)-3-oxo-4-azaandrost-1-ene-17-carboxamide, finasteride, finasteride (medication), FINASTERIDE, Finasteride [Chemical/Ingredient], finasteride products, Finasteride (product), Finasteride (substance) |
Swedish | Finasterid |
Czech | finasterid |
Finnish | Finasteridi |
Russian | FINASTERID, ФИНАСТЕРИД |
Japanese | フィナステリド |
Polish | Finasteryd |
Spanish | Finasteride, finasterida (producto), finasterida (sustancia), finasterida, Finasterida |
Portuguese | Finasteride, Finasterida |
French | Finastéride |
German | Finasterid |
Italian | Finasteride |
Ontology: Proscar (C0678149)
Concepts | Pharmacologic Substance (T121) , Steroid (T110) |
MSH | D018120 |
English | finasteride (Proscar), proscar, Proscar, Cahill May Roberts Brand of Finasteride, MSD Chibropharm Brand of Finasteride, Merck Brand 2 of Finasteride, Merck Frosst Brand 2 of Finasteride, Merck Sharp & Dhome Brand 2 of Finasteride |
Ontology: Propecia (C0722858)
Concepts | Steroid (T110) , Pharmacologic Substance (T121) |
MSH | D018120 |
English | finasteride (Propecia), propecia, Propecia, Propeshia, MSD Brand of Finasteride, Merck Brand 1 of Finasteride, Merck Frosst Brand 1 of Finasteride, Merck Sharp & Dohme Brand 1 of Finasteride |
Ontology: Dutasteride (C0754659)
Definition (NCI) | A synthetic 4-azasteroid compound. Dutasteride competitively and specifically binds to isoenzymes 1 and 2 of 5 alpha-reductase, forming stable enzyme complexes and inhibiting the conversion of testosterone to 5 alpha-dihydrotestosterone (DHT); the reduction in DHT activity may mitigate or prevent enlargement of the prostate gland. The type 2 5 alpha-reductase isoenzyme is primarily active in the reproductive tissues, while the type 1 isoenzyme is also active in skin and the liver. |
Definition (NCI_NCI-GLOSS) | A drug used to treat symptoms of an enlarged prostate gland. It is being studied in the treatment of male hair loss and prostate cancer. Avodart blocks enzymes the body needs to make male sex hormones. It is a type of 5-alpha reductase inhibitor. |
Definition (PDQ) | A synthetic 4-azasteroid compound. Dutasteride competitively and specifically binds to isoenzymes 1 and 2 of 5-alpha-reductase, forming stable enzyme complexes and inhibiting the conversion of testosterone to 5-alpha-dihydrotestosterone (DHT); the reduction in DHT activity may mitigate or prevent enlargement of the prostate gland. The type 2 5-alpha-reductase isoenzyme is primarily active in the reproductive tissues, while the type 1 isoenzyme is also active in skin and the liver. Check for "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=479183&idtype=1" active clinical trials or "http://www.cancer.gov/Search/ClinicalTrialsLink.aspx?id=479183&idtype=1&closed=1" closed clinical trials using this agent. ("http://nciterms.nci.nih.gov:80/NCIBrowser/ConceptReport.jsp?dictionary=NCI_Thesaurus&code=C47503" NCI Thesaurus) |
Concepts | Steroid (T110) , Pharmacologic Substance (T121) |
MSH | C108373 |
SnomedCT | 408009000, 385570006, 385572003 |
English | DUTASTERIDE @ @ UNIDENTIFIED, DUTASTERIDE UNIDENTIFIED, alpha,alpha,alpha,alpha',alpha',alpha'-Hexafluoro-3-oxo-4-aza-5alpha-androst-1-ene-17beta-carboxy-2',5'-xylidide, Avolve,(5alpha,17beta)-N-(2,5-Bis(trifluoromethyl)phenyl)-3-oxo-4-azaandrost-1-ene-17-carboxamide, 17beta-N-(2,5-bis(trifluoromethyl))phenyl-carbamoyl-4-aza-5alpha-androst-1-en-3-one, dutasteride (medication), DUTASTERIDE, dutasteride [Chemical/Ingredient], Dutasteride, Dutasteride (product), Dutasteride (substance), dutasteride |
Spanish | dutasterida (producto), dutasterida (sustancia), dutasterida |
Ontology: 5-alpha Reductase Inhibitor [EPC] (C1318898)
Concepts | Pharmacologic Substance (T121) |
English | 5-alpha Reductase Inhibitor, 5-alpha Reductase Inhibitor [EPC] |