Finasteride (By mouth)
fin-AS-ter-ide
Treats benign prostatic hyperplasia (enlarged prostate). Also treats hair loss in men.
Drug classes
Alopecia Agent, Benign Prostatic Hypertrophy Agent (About this – PubMed Health)
Uses
Uses of This Medicine
Note: Women who are pregnant or may become pregnant should not use finasteride or handle the crushed or broken tablets. Finasteride can cause birth defects in male babies.
Finasteride is used to treat men with benign prostatic hyperplasia (BPH) and male pattern hair loss, also called androgenetic alopecia. BPH is caused by an enlarged prostate. Men with BPH usually have difficulty urinating, a decreased flow of urination, hesitation at the beginning of urination, and a need to get up at night to urinate. Finasteride will make these symptoms less severe and reduce the chance that prostate surgery will be needed. It may be used alone or in combination with other medicines such as an alpha-blocker (doxazosin, Cardura®) to treat BPH. For men with hair loss, finasteride will increase the number of scalp hairs but will not increase the amount of body hair.
Finasteride blocks the action of an enzyme called 5-alpha-reductase. This enzyme changes testosterone to another hormone that causes the prostate to grow or hair loss in males. It will increase testosterone levels in the body, which decreases prostate size and increases hair growth on the scalp. The effect of finasteride on the prostate and scalp will only last as long as the medicine is taken. When it is stopped, the prostate begins to grow again and the hair will be lost.
This medicine is available only with your doctor’s prescription.
Other uses (PubMed Health)
How To Use
Tablet
Your doctor will tell you how much medicine to use. Do not use more than directed.
You may take this medicine with or without food.
Take this medicine at the same time each day.
For hair loss, you may need to take this medicine for 3 months or longer before you see an effect.
For an enlarged prostate, you may need to take this medicine for up to 6 months to see the full effect.
Read and follow the patient instructions that come with this medicine. Talk to your doctor or pharmacist if you have any questions.
If a dose is missed:
If you miss a dose or forget to take your medicine, skip the missed dose and take your next regular dose. Do not use extra medicine to make up for a missed dose.
How to Store and Dispose of This Medicine:
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.
Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed.
Keep all medicine out of the reach of children. Never share your medicine with anyone.
Drugs and Foods to Avoid
Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.
When Not To Use
You should not use this medicine if you have had an allergic reaction to finasteride. Women and children should not use this medicine.
Warnings
Women who are pregnant or may become pregnant should avoid handling or touching this medicine. This medicine can get into the body through the skin and may harm an unborn male baby. If any of this medicine gets on the skin of a woman, wash the area immediately with soap and water.
Make sure your doctor knows if you have liver disease or severe problems urinating.
This medicine will not cure an enlarged prostate problem or male pattern baldness. Once you stop using this medicine, the prostate will begin to grow again within a few months and any new hair will be lost within 12 months.
This medicine may cause changes to the breast tissue. Tell your doctor if you have any lumps, pain, tenderness, or an enlargement of the breasts while using this medicine.
This medicine will not prevent prostate cancer but may increase your risk of developing high-grade prostate cancer. Tell your doctor if you have concerns about this risk.
This medicine may affect the results of the prostate specific antigen (PSA) test, which may be used to detect prostate cancer. Make sure you tell all of your doctors that you are using this medicine.
This medicine may cause a decrease in the amount of semen you ejaculate during sex. This will not affect your sperm count or your ability to have children.
Your doctor will check your progress and the effects of this medicine at regular visits. Keep all appointments. Blood tests may be needed to check for unwanted effects.
Possible side effects
Summary More details
Call your doctor right away if you notice any of these side effects:
Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
Breast swelling, pain, or tenderness.
Lightheadedness, dizziness, or fainting.
Lumps in the breast or under the arm.
Pain in the testicles.
Swelling in your hands, ankles, or feet.
If you notice these less serious side effects, talk with your doctor:
Decrease in the amount of semen.
Loss of interest in sex or the ability to have sex (impotence).
Skin rash.
Sleepiness or unusual drowsiness.
Stuffy or runny nose.
Trouble having or keeping an erection.
Weakness.
If you notice other side effects that you think are caused by this medicine, tell your doctor.
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
More side effects of this drug
Brand names include
Propecia, Proscar
There may be other brand names for this medicine.