Finasteride (patient information)
Template:Drug header Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Why this medication is prescribed
Finasteride is used alone or in combination with other medications to treat benign prostatic hypertrophy (BPH, enlargement of the prostate gland). Finasteride improves symptoms of BPH such as frequent and difficult urination and may reduce the chance of acute urinary retention (suddenly being unable to pass urine). It also may decrease the chance of needing prostate surgery. Finasteride is in a class of medications called 5-alpha reductase inhibitors. It works by blocking the body's production of a male hormone that causes the prostate to enlarge.
How this medication should be used
Finasteride comes as a tablet to take by mouth. It is usually taken once a day with or without food. Take finasteride at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take finasteride exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Continue to take finasteride even if you feel well. Do not stop taking finasteride without talking to your doctor.
Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.
Other uses for this medicine
Finasteride is also sometimes used to treat male pattern baldness. Talk to your doctor about the risks of using this drug for your condition.
Special precautions
Before taking finasteride:
- tell your doctor and pharmacist if you are allergic to finasteride or any other medications.
- tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take.
- tell your doctor if you have or have ever had a blockage of urine flow or liver disease.
- you should know that finasteride is only for use in men. If taken by pregnant women, finasteride can cause abnormalities in the male fetus. Women who are or may be pregnant should not touch broken or crushed finasteride tablets.
What to do if you forget a dose
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
Side effects
Minor side effects
Finasteride may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- impotence (inability to have or maintain an erection)
- decreased libido (interest in sex)
- decreased volume of ejaculate (amount of semen)
Severe side effects
Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately:
- changes in the breasts such as lumps, pain, or nipple discharge
Finasteride may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/MedWatch/report.htm] or by phone [1-800-332-1088].
Storage conditions needed for this medication
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.
In case of emergency/overdose
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.
Other information
Keep all appointments with your doctor.
Before having any laboratory test, tell your doctor and the laboratory personnel that you are taking finasteride.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
Brand names
- Proscar®