Type of Drug:

Enzyme inhibitors; androgen hormone inhibitors.

How the Drug Works:

Dutasteride and finasteride inhibit the production of androgen, a hormone that is a major cause of prostate growth. By reducing the amount of androgen, dutasteride and finasteride help relieve urinary symptoms often associated with overdevelopment or enlargement of the prostate (benign prostatic hyperplasia [BPH]).

By inhibiting the production of androgen, finasteride interrupts processes that lead to male pattern baldness (hair loss on the crown of the head or the front scalp area).

Uses:

Doutasteride, Proscar: To treat symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate to improve symptoms, reduce the risk of acute urinary retention, and reduce the risk of the need for prostate surgery. Not indicated for use in women or children.

Propecia: To treat male pattern hair loss (vertex and anterior midscalp).

Effectiveness with other types of hair loss has not been determined. Not indicated for use in women or children.

Unlabeled Uses: Finasteride is being investigated in combination with flutamide as therapy following radical prostatectomy. Other potential uses include prevention of the progression of first-stage prostate cancer, treatment of acne in women, abnormal hair growth.

Precautions:

Pregnancy: Do not use during pregnancy. The risk of use in a pregnant woman clearly outweighs any possible benefit. Not indicated for use in women. Women who are pregnant or may become pregnant should not handle broken or crushed tablets or capsules because of the potential for absorption and potential risk to a male fetus. Similarly, when a male patient’s sexual partner is or may become pregnant, the patient should either avoid exposing his partner to his semen or discontinue therapy.

Breastfeeding: It is not known if these drugs appear in breast milk; they are not indicated for use in women. Consult your doctor before you begin breastfeeding.

Children: Safety and effectiveness have not been established; not indicated for use in patients younger than 18 years of age.

Lab tests may be required during and following treatment. Tests include prostate cancer screenings and urinary flow and volume monitoring.

Drug Interactions:

Tell your doctor or pharmacist if you are taking or planning to take any over­the-counter or prescription medications or dietary supplements with these drugs. Drug doses may need to be modified or a different drug pre­scribed. Ritonavir (Norvir) interacts with dutasteride.

Side Effects:

Every drug is capable of producing side effects. Many patients experience no, or minor, side effects. The frequency and severity of side effects depend on many factors including dose, duration of therapy, and individual susceptibility. Possible side effects include impotence, decreased sex drive, decreased amount of ejaculate, testicular pain, and breast tenderness and enlargement.

Guidelines for Use:

• Read the patient information insert before beginning therapy.
• Dosage is individualized. Take exactly as prescribed.
• Do not stop taking or change the dose, unless instructed by your doctor.
• Male pattern baldness - In general, three months of daily treatment is necessary before benefit is observed. Continued use is recommended to sustain benefit. Stopping treatment can reverse results within 12 months.
• Benign prostatic hyperplasia (BPH) - Six to twelve months of treatment may be necessary to determine response.
• Take without regard to meals.
• Swallow dutasteride capsules whole.
• Dutasteride long-term treatment - The incidence of most drug-related adverse events (eg, impotence, decreased sex drive, ejaculation disorder) will decrease with duration of treatment. The incidence of drug­related breast tenderness and enlargement may remain constant during therapy.
• Women who are pregnant or may become pregnant should not handle broken or crushed tablets or capsules because of the potential for absorption and potential risk to male fetus. Similarly, when a male patient’s sexual partner is or may become pregnant, the patient should either avoid exposing his partner to his semen or discontinue therapy.
• The amount of ejaculate may be decreased. This should not interfere with normal sexual function. However, impotence (erectile dysfunction) and decreased sex drive may occur .
• Men treated with dutasteride should not donate blood until at least 6 months have passed following their last dose to prevent pregnant women from receiving dutasteride through blood transfusion.
• Lab tests may be required during and following treatment. Be sure to keep appointments.
• Store at room temperature (59° to 86°F). Protect from light and moisture. Keep container tightly closed.