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Indications ⬇

REMS

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Use Cautiously in:

Adv. Reactions/Side Effects ⬆ ⬇

Endo: gynecomastia

GU: ↓libido, ↓volume of ejaculate, erectile dysfunction, infertility, PROSTATE CANCER (HIGH-GRADE)

Misc: ANGIOEDEMA, BREAST CANCER

Interactions ⬆ ⬇

Drug-drug:

Availability ⬆ ⬇

(Generic available)

Route/Dosage ⬆ ⬇

Benign Prostatic Hypertrophy

Androgenetic Alopecia

US Brand Names ⬆ ⬇

Propecia, Proscar

Action ⬆ ⬇

  • Inhibits the enzyme 5-alpha-reductase, which is responsible for converting testosterone to its potent metabolite 5-alpha-dihydrotestosterone in prostate, liver, and skin; 5-alpha-dihydrotestosterone is partially responsible for prostatic hyperplasia and hair loss.
Therapeutic effects:
  • Reduced prostate size with associated decrease in urinary symptoms.
  • Decreases hair loss; promotes hair regrowth.

Classifications ⬆ ⬇

Therapeutic Classification: benign prostatic hyperplasia bph agents, hair regrowth stimulants

Pharmacologic Classification: androgen inhibitors

Pharmacokinetics ⬆ ⬇

Absorption: Well absorbed after oral administration (63%).

Distribution: Enters prostatic tissue and crosses the blood-brain barrier. Remainder of distribution not known.

Protein Binding: 90%.

Metabolism/Excretion: Mostly metabolized; 39% excreted in urine as metabolites; 57% excreted in feces.

Half-Life: 6 hr (range 6–15 hr; slightly ↑ in patients >70 yr).

Time/Action Profile ⬆ ⬇

(↓ in dihydrotestosterone levels‡)
ROUTEONSETPEAKDURATION
POrapid8 hr2 wk

‡Clinical effects as noted by urinary tract symptoms and hair regrowth may not be evident for several mo and remain for 4 mo after discontinuation.

Patient/Family Teaching ⬆ ⬇

Pronunciation ⬆ ⬇

fi-NAS-teer-ide

Code ⬆

NDC Code