Silodosin is used by men to treat the symptoms of an enlarged prostate (benign prostatic hyperplasia-BPH). It does not shrink the prostate, but it works by relaxing the muscles in the prostate and the bladder. This helps to relieve symptoms of BPH such as difficulty in beginning the flow of urine, weak stream, and the need to urinate often or urgently (including during the middle of the night).

Silodosin belongs to a class of drugs known as alpha blockers.

Do not use this medication to treat high blood pressure.

Take this medication by mouth as directed by your doctor, usually once daily with a meal.

If you have difficulty swallowing this medication whole, you may sprinkle the entire contents of a capsule on a small amount (such as a tablespoon) of cool soft applesauce just before taking. Swallow the mixture right away (within 5 minutes). Do not chew the mixture, and do not save it for future use. Do not use hot applesauce. Drink a glass of cool water after each dose.

Silodosin may cause a sudden drop in your blood pressure, which could lead to dizziness or fainting. This risk is higher when you first start taking this drug, after your doctor increases your dose, or if you restart treatment after you stop taking it. During these times, avoid situations where you may be injured if you faint.

To avoid injury from dizziness or fainting, your doctor may tell you to take your first dose of silodosin with food at bedtime so that your body can get used to its effects.

The dosage is based on your medical condition and response to treatment.

Take this medication regularly to get the most benefit from it. To help you remember, take it with the same meal each day.

Tell your doctor if your condition does not improve or if it worsens.

You should not take Rapaflo if you have severe kidney or liver disease.

Do not take silodosin together with similar medicines such as alfuzosin, doxazosin, prazosin, tamsulosin, or terazosin.

Rapaflo may cause dizziness or fainting, especially when you first start taking it. Be careful if you drive or do anything that requires you to be alert. Avoid standing for long periods of time or becoming overheated during exercise and in hot weather. Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.

Rapaflo can affect your pupils during cataract surgery. Tell your eye surgeon ahead of time that you are using Rapaflo. Do not stop using Rapaflo before surgery unless your surgeon tells you to.

There are many other drugs that can interact with silodosin. Tell your doctor about all medications you use.

You should not take Rapaflo if you are allergic to silodosin, or if you have:

• severe liver disease; or
• severe kidney disease.

Some medicines can interact with silodosin and should not be used at the same time. Your doctor may need to change your treatment plan if you use any of the following drugs:

• imatinib;
• isoniazid;
• nefazodone;
• an antibiotic - clarithromycin, telithromycin;
• antifungal medicine - itraconazole, ketoconazole, posaconazole, voriconazole;
• heart medication - nicardipine, quinidine;
• antiviral medicine to treat hepatitis C or HIV/AIDS - atazanavir, boceprevir, cobicistat, delavirdine, fosamprenavir, indinavir, nelfinavir, ritonavir, saquinavir, telaprevir; or
• medicines similar to Rapaflo - alfuzosin, doxazosin, prazosin, tamsulosin, or terazosin.

To make sure Rapaflo is safe for you, tell your doctor if you have ever had:

• low blood pressure;
• kidney disease (or if you are on dialysis);
• heart disease;
• prostate cancer;
• a condition for which you take a diuretic or "water pill"; or
• if you are on a low-salt diet.

Rapaflo can affect your pupils. If you have cataract surgery, tell your surgeon ahead of time that you use this medicine.

Rapaflo is not for use in women, and the effects of this medicine during pregnancy or in breastfeeding women are unknown.

Rapaflo is not approved for use by anyone younger than 18 years old.

Dizziness, lightheadedness, or ejaculation problems may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including: fainting.

Rarely, males may have a painful or prolonged erection lasting 4 or more hours. If this occurs, stop using this drug and get medical help right away, or permanent problems could occur.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:

• kidney disease
• liver disease
• low blood pressure
• prostate cancer
• an unusual or allergic reaction to silodosin, medicines, foods, dyes, or preservatives
• pregnant or trying to get pregnant
• breast-feeding

How should I use this medicine?

Take this medicine by mouth with a meal. Follow the directions on the prescription label. Do not cut, crush or chew this medicine. If you have difficulty swallowing the capsules, you may open the capsule and sprinkle the contents over a tablespoon of cool applesauce. Do not use hot applesauce or any other food or liquid. Swallow the dose immediately (within 5 minutes) after preparing it. Do not chew. Follow with an 8 ounce (240 ml) glass of water. Do not take your medicine more often than directed. Do not stop taking your medicine unless your doctor tells you to.

Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What may interact with this medicine?

Do not take this medicine with any of the following medications:

• clarithromycin
• itraconazole
• ketoconazole
• ritonavir

This medicine may also interact with the following medications:

• cyclosporine
• erythromycin
• medicines for erectile dysfunction like sildenafil, tadalafil, vardenafil
• medicines for blood pressure
• other medicines for benign prostatic hyperplasia like alfuzosin, doxazosin, phentolamine, phenoxybenzamine, prazosin, terazosin