Proscar

Proscar is a drug that can be used for the treatment of benign prostatic hyperplasia, a condition in which the prostate becomes enlarged. By decreasing DHT levels, the medication can help shrink an enlarged prostate and relieve associated symptoms. Proscar comes in tablet form and is generally taken once a day. Potential side effects may include impotence, decreased sex drive, and decreased ejaculate amount.

What Is Proscar?

Proscar® (finasteride) is a prescription medicine that has been licensed as treatment for an enlarged prostate. An enlarged prostate is also known medically as benign prostatic hyperplasia, benign prostatic hypertrophy, or BPH.
 
(Click Proscar Uses for more information, including possible off-label uses.)
 

Who Makes It?

Proscar is manufactured by Merck & Co, Inc. Generic Proscar is made by several manufacturers.
 

How Does Proscar Work?

Proscar works by blocking the conversion of testosterone into DHT (dihydrotestosterone), which decreases the amount of DHT in the body. Since DHT is important for enlargement of the prostate, using this drug to decrease DHT levels can treat an enlarged prostate. In most men, Proscar can help shrink the prostate, helping to relieve their enlarged prostate symptoms.
 

Effects of Proscar

Several studies have looked at how well Proscar treats an enlarged prostate. In particular, there has been one large study that examined several of the effects of the drug for men with BPH, with the following results.
Symptoms of BPH
The men in this study were asked to rate the following symptoms of BPH:
 
  • Decreased size and force of urine stream
  • Feeling of incomplete bladder emptying when urinating
  • Delayed or interrupted urination
  • Having to get up to urinate frequently during the night
  • Having to urinate frequently during the day
  • Needing to strain or push the flow of urine.
     
The men who took Proscar had significant improvement in their BPH symptoms, compared to the men who did not take it. While some saw improvement right away, in general, it took about six months to see the improvement for most men. This improvement lasted throughout the entire study period (four years).
 
Acute Urinary Retention
This study also looked at how many men had acute urinary retention. If an enlarged prostate is severe, a man may not be able to urinate at all. This is known medically as acute urinary retention and usually requires catheterization (inserting a small tube through the penis into the bladder in order to empty the urine). Of the men who took Proscar, 2.8 percent experienced acute urinary retention that required catheterization, compared to 6.6 percent of men who did not take it.
 
Surgery
In this study, 4.6 percent of men who took Proscar needed to have BPH surgery, while 10.1 percent of men who did not take it needed to have surgery.
 
Urine Flow
Men who took Proscar also had an improvement in the rate of urine flow. This increased flow rate was seen as early as the fourth month after starting the drug and continued throughout the entire study.
 

When and How to Take It

Some general considerations for when and how to take Proscar include the following:
 
  • The medication comes in tablet form. It is taken by mouth once daily.
  • It may take as long as six months before results can be seen.
  • Proscar can be taken with or without food.
  • Your dose should be taken at the same time each day to maintain an even level in your blood.
  • For Proscar to work properly, it must be taken as prescribed. The medication will not work if you stop taking it.
     

Dosing Information

There is only one dose of Proscar available for enlarged prostate treatment -- Proscar 5 mg once daily.
 
As with any medication, do not adjust your dose unless your healthcare provider specifically instructs you to do so.
 
(Click Proscar Dosage for more information.)
 

Side Effects of Proscar

As with any medicine, side effects are possible with Proscar. However, not everyone who takes the medicine will experience side effects. In fact, most people tolerate it well. If side effects do occur, they are often minor and either require no treatment or can easily be treated by you or your healthcare provider. Serious side effects are less common.
 
The most common side effects include:
 
(Click Proscar Side Effects to learn more, including potentially serious side effects you should report to your healthcare provider.)
 
You can also read about specific side effects by clicking the following eMedTV links:
 

Drug Interactions

There are no known drug interactions with Proscar (see Proscar Drug Interactions for more information).
 

What Should I Tell My Healthcare Provider Before Taking Proscar?

You should talk with your healthcare provider before taking this drug if you have:
 
  • Liver disease or liver failure, including cirrhosis
  • Any allergies, including allergies to foods, dyes, or preservatives.
     
Also, let your healthcare provider know if you are:
 
Tell your healthcare provider about all other medicines you may currently be taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
 
(Click Proscar Warnings and Precautions to learn more, including information on who should not take the drug.)
 

What If I Take an Overdose?

In studies, large doses of Proscar did not cause any overdose symptoms. However, if you happen to take too much, or if you are a pregnant woman who has taken any amount, seek immediate medical attention.
 
(Click Proscar Overdose for more information.)
 

How Should Proscar Be Stored?

Proscar should be stored at room temperature away from moisture or heat. The tablets should be kept in an airtight container. Because the medication is so dangerous for pregnant women, women should not touch broken or crushed tablets if they are pregnant or may be pregnant.
 
Keep this and all medications out of the reach of children.
 

What Should I Do If I Miss a Dose?

If you do not take your Proscar as scheduled, take your missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule. Do not take a double dose.
 

Available Strengths

Proscar tablets are available in one strength -- Proscar 5 mg tablets.
 

Proscar Versus Propecia

Propecia®, a medication used for treating male pattern baldness, contains the same active ingredient as Proscar -- finasteride. However, Propecia is available only in 1-mg tablets, which is not the correct dose for treating BPH (see Proscar and Hair Loss for more information).
 
(Click Propecia and Proscar for more information about the differences between these two medications.)
 

Generic Proscar

Proscar is currently available in generic form (see Generic Proscar for more information).
 
Written by/reviewed by: Kristi Monson, PharmD; Arthur Schoenstadt, MD
Last reviewed by: Kristi Monson, PharmD;
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