Dutasteride

Oral
Benign prostatic hyperplasia

Severe: Contraindicated.

May be taken with or without food.

Women, childn and adolescents. Severe hepatic impairment. Pregnancy and lactation.

Mild to moderate hepatic impairment.

Impotence, decreased libido, ejaculation disorder, breast disorders (e.g. tenderness, enlargement), breast cancer, hypersensitivity reactions (e.g. rash, pruritus, urticaria, localised oedema, serious skin reactions, angioedema), depressed mood, testicular pain and swelling, decreased prostate-specific antigen (PSA) concentration.

PO: X

Avoid donating blood during treatment and for at least 6 mth following treatment cessation.

Monitor prostate-specific antigen (PSA) levels.

Plasma concentrations may be increased when used concomitantly w/ moderate or potent CYP3A4 inhibitors.

May interfere with interpretation of prostate-specific antigen test results.

Description:
Mechanism of Action: Dutasteride, a 4-azo analog of testosterone, is a selective inhibitor of steroid 5α-reductase isoenzymes type 1 (skin and hepatic) and type 2 (reproductive tissues). This results in inhibition of the conversion of testosterone to dihydrotestosterone and markedly suppresses serum dihydrotestosterone levels.
Pharmacokinetics:
Absorption: Absorbed from the GI tract. Bioavailability: Approx 60%. Time to peak plasma concentration: 1-3 hr.
Distribution: Plasma protein binding: >99.5%.
Metabolism: Undergoes hepatic metabolism by CYP3A4 and CYP3A5 isoenzymes.
Excretion: Via faeces (40% as metabolites; approx 5% as unchanged drug) and urine (<1% as unchanged drug). Elimination half-life: Approx 3-5 wk.

Source: National Center for Biotechnology Information. PubChem Database. Dutasteride, CID=6918296, https://pubchem.ncbi.nlm.nih.gov/compound/Dutasteride (accessed on Jan. 21, 2020)

Store at 25°C.

Drugs for Bladder & Prostate Disorders

Anon. Dutasteride. AHFS Clinical Drug Information [online]. Bethesda, MD. American Society of Health-System Pharmacists, Inc. https://www.ahfscdi.com. Accessed 12/11/2014.

Anon. Dutasteride. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 12/11/2014.

Avodart- Dutasteride Capsule, Liquid filled. DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 12/11/2014.

Buckingham R (ed). Dutasteride. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 12/11/2014.