Generic Name: silodosin, Oral capsule

Generic Name:

silodosin, Oral capsule

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SECTION 1 of 5

Highlights for silodosin

Oral capsule
1

Silodosin is used in adult men to treat benign prostatic hyperplasia (BPH).

2

Silodosin helps to lessen your BPH symptoms and improve your ability to urinate.

3

Silodosin is available as an oral capsule.

4

The usual dose is 8 mg taken once per day with a meal.

5

Common side effects include problems with ejaculation, dizziness, diarrhea, low blood pressure when you stand up from sitting or lying down, headache, swelling of your nose or throat, and stuffy nose.

IMPORTANT INFORMATION

Fainting and dizziness warning

Silodosin may cause low blood pressure when you stand up from sitting or lying down, which may lead to dizziness and fainting. Don’t drive, operate machinery, or perform dangerous tasks until you know how it affects you.

Cataract surgery warning

Silodosin may affect your pupils during cataract surgery. A complication known as intraoperative floppy iris syndrome (IFIS) has occurred in some people who were taking or recently took this type of drug.

Drug Features

Silodosin is a prescription medication. It’s available as an oral capsule.

This drug may be used as part of a combination therapy. That means you need to take it with other drugs.

Why It's Used

Silodosin is used to treat the symptoms of benign prostatic hyperplasia (BPH) in men with an enlarged prostate.

More Details

How It Works

Silodosin belongs to a class of drugs called alpha-1 blockers. It works by relaxing muscles in your prostate and bladder.

More Details

Why It's Used

Silodosin is used to treat the symptoms of benign prostatic hyperplasia (BPH) in men with an enlarged prostate.

When the prostate is enlarged, it can pinch or squeeze your urethra and affect your ability to urinate. This may cause:

  • nighttime urination (nocturia)
  • sudden urge to urinate
  • frequent urge to urinate
  • difficulties in starting to urinate
  • feeling like you can’t completely empty your bladder
  • weak urine flow
  • straining while urinating
  • dribbling (leaking) after urination

How It Works

Silodosin belongs to a class of drugs called alpha-1 blockers. It works by relaxing muscles in your prostate and bladder.

Alpha-1 receptors are located in your prostate and bladder. They’re responsible for the contraction of the smooth muscles of the bladder and prostate. Silodosin blocks these receptors, which causes the smooth muscles in the prostate and bladder to relax. This will reduce your BPH symptoms and improve your ability to urinate.

SECTION 2 of 5

silodosin Side Effects

Oral capsule

Most Common Side Effects

The most common side effects that occur with silodosin include:

  • dizziness

  • diarrhea

  • low blood pressure when you stand up from sitting or lying down (orthostatic hypotension)

  • headache

  • retrograde ejaculation (occurs when semen enters the bladder instead of out of the tip of the penis

  • swelling of your nose or throat (nasopharyngitis)

  • stuffy nose

Mild side effects may disappear within a few days or a couple of weeks. Talk to your doctor or pharmacist If they’re more severe or don’t go away.

Serious Side Effects

If you experience any of these serious side effects, call your doctor right away. If your symptoms are potentially life threatening, or if you think you’re experiencing a medical emergency, call 9-1-1.

  • allergic (drug hypersensitivity) reaction. Symptoms may include:

    • swelling of your face, lips, tongue, or throat
    • problems with breathing or swallowing
    • skin rash
    • itching
    • hives
    • blisters on your skin or in your mouth, nose, or eyes
    • peeling skin
    • fainting or feeling dizzy
    • very rapid heartbeat
  •  liver problems. Symptoms may include: 

    • yellowing of your skin or the whites of your eyes
    • nausea
    • vomiting
    • loss of appetite
    • stomach pain and swelling
    • bruising easily
    • pale stool color
    • dark urine
    • unusual or unexplained tiredness
  • prolonged erection (priapism).This is an erection that lasts longer than 4 hours.

  • sudden drop in blood pressure, especially when you stand up from sitting or lying down. Symptoms may include:

    • dizziness
    • feeling lightheaded
    • fainting (syncope)
Pharmacist's Advice
Healthline Pharmacist Editorial Team

Silodosin doesn’t cause drowsiness.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare provider who knows your medical history.
SECTION 3 of 5

silodosin May Interact with Other Medications

Oral capsule

Silodosin can interact with other medications, herbs, or vitamins you might be taking. That’s why your doctor should manage all of your medications carefully. If you’re curious about how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Note: You can reduce your chances of drug interactions by having all of your prescriptions filled at the same pharmacy. That way, a pharmacist can check for possible drug interactions.

Food Interactions

Grapefruit juice can interfere with the same enzymes that break down or process silodosin. If you drink grapefruit juice while taking silodosin, it may increase the levels of silodosin in your body and possibly cause increased side effects.

Alcohol Interaction

Silodosin can make you dizzy. Consuming alcohol may also make you dizzy and drowsy. You should limit the amount of alcohol you drink.

Medications That Might Interact with This Drug

Antifungals

These medications increase the levels of silodosin in your body and cannot be taken with silodosin:

  • itraconazole (Sporanox)
  • ketoconazole (Nizoral)

This medication may increase the levels of silodosin in your body:

  • posaconazole (Noxafil)

Blood pressure medicines

These belong to the drug class calcium channel blockers. These medications may increase the levels of silodosin in your body:

  • diltiazem (Cardizem)
  • verapamil (Calan)

Using blood pressure medications and silodosin together may increase your risk of low blood pressure, a sudden drop in your blood pressure when getting up from a sitting or lying position, or fainting.

Antibiotics

This medication increases the levels of silodosin in your body and cannot be taken with silodosin:

  • clarithromycin (Biaxin) 

This medication may increase the levels of silodosin in your body:

  • erythromycin

Human immunodeficiency virus (HIV) medications

These belong to a drug class called protease inhibitors. These medications may increase the levels of silodosin in your body:

  • atazanavir (Reyataz)
  • darunavir (Prezista®, Prezcobix)
  • elvitegravir/cobicistat/emtricitabine/tenofovir (Stribild)
  • fosamprenavir (Lexiva)
  • lopinavir/ritonavir (Kaletra)
  • indinavir (Crixivan)
  • nelfinavir (Viracept)
  • saquinavir (Invirase)

This medication increases the levels of silodosin in your body and cannot be taken with silodosin:

  • ritonavir (Norvir)

Immune suppressing drug

This medication may increase the levels of silodosin in your body:

  • cyclosporine

Hepatitis C drug

This drug belongs to a class called HVC protease inhibitors. This medication may increase the levels of silodosin in your body:

  • boceprevir (Victrelis)

Other drugs used to treat benign prostatic hyperplasia (BPH)

These medications may cause your blood pressure to become too low if taken with silodosin. They may also increase your risk of a sudden drop in blood pressure when getting up from sitting or lying down (orthostatic hypotension), which may cause dizziness or fainting.

  • alfuzosin (Uroxatral)
  • doxazosin (Cardura)
  • prazosin (Minipress)
  • terazosin (Hytrin)
  • tamsulosin (Flomax)

Blood pressure drugs

These medications may cause your blood pressure to become too low if taken with silodosin. They may also increase your risk of a sudden drop in blood pressure when getting up from sitting or lying down (orthostatic hypotension), which may cause dizziness or fainting. 

  • metoprolol
  • carvedilol
  • atenolol
  • lisinopril
  • losartan
  • valsartan
  • amlodipine
  • clonidine

Erectile dysfunction drugs

These medications may cause your blood pressure to become too low if taken with silodosin. They may also increase your risk of a sudden drop in blood pressure when getting up from sitting or lying down (orthostatic hypotension), which may cause dizziness or fainting.

  • sildenafil (Viagra)
  • tadalafil (Cialis)
  • vardenafil (Levitra)

Pulmonary hypertension drug

This medication may cause your blood pressure to become too low if taken with silodosin. It may also increase your risk of a sudden drop in blood pressure when getting up from sitting or lying down (orthostatic hypotension), which may cause dizziness or fainting.

  • sildenafil (Revatio)

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.

People with kidney disease

Your body gets rid of silodosin partly through your kidneys. If your kidneys aren’t working well, more of the drug may stay in your body. This increases your risk of side effects. Silodosin isn’t recommended if you have severe kidney disease. If you have moderate kidney disease, your doctor may reduce your dose.

People with liver disease

Silodosin is processed by your liver. If your liver isn’t working well, more of the drug may stay in your body. This increases your risk of side effects. Silodosin isn’t recommended if you have severe liver disease, because it hasn’t been studied in this population.

People with low pressure (hypotension)

Silodosin may cause low blood pressure when you stand up from sitting or lying down, dizziness, and even further lowering of your blood pressure. Don’t drive, operate machinery, or perform dangerous tasks until you know how it affects you.

Pregnant women

Silodosin is used to treat BPH in men. It isn’t intended for women.

Silodosin is a pregnancy category B drug. That means two things:

  1. Studies of the drug in pregnant animals haven’t shown risk to the fetus.
  2. There aren’t enough studies done in pregnant women to show the drug poses a risk to the fetus.

Women who are breast-feeding

Silodosin is used to treat BPH in men. It isn’t intended for women. It isn’t known if silodosin passes through breast milk.

For seniors

If you’re 65 years or older, you may be at higher risk for low blood pressure when you stand up from sitting or lying down (orthostatic hypotension).

For children

It isn’t known if silodosin is safe and effective in children younger than 18 years old. It isn’t recommended for use in children.

Allergies

Silodosin can cause a severe allergic reaction. Symptoms may include:

  • trouble breathing
  • swelling of your throat or tongue
  • hives
  • itching
  • rash

Don’t take this drug again if you’ve ever had an allergic reaction to it. Taking it again could be fatal.

SECTION 4 of 5

How to Take silodosin (Dosage)

Oral capsule

All possible dosages and forms may not be included here. Your dose, form, and how often you take it will depend on: 

  • your age
  • the condition being treated
  • how severe your condition is
  • other medical conditions you have
  • how you react to the first dose

What Are You Taking This Medication For?

Benign prostatic hyperplasia
Form: Oral capsule
Strengths: 4 mg and 8 mg
Adult Dosage (ages 18-64 years)

The recommended dose is 8 mg taken once per day with a meal.

Child Dosage (ages 0-17 years)

The safety and effectiveness of silodosin in children haven’t been established. Silodosin isn’t recommended for children younger than 18 years old.

Senior Dosage (ages 65 years and older)

As you age, your organs (such as liver or kidneys) may not work as well. Your body may process this drug more slowly. Too much drug in your body can lead to more side effects. Based on how well your liver and kidneys are working, your doctor may decide to adjust your dose or not prescribe this drug at all.

Special Considerations

Kidney disease: Dosing for silodosin depends on your kidney function.

  • Severe kidney disease: Silodosin isn’t recommended.
  • Moderate kidney disease: The dose may be 4 mg taken once per day with a meal.
  • Mild kidney disease: The dose may be 8 mg taken once per day with a meal.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always to speak with your doctor or pharmacist about dosages that are right for you.
Pharmacist's Advice
Healthline Pharmacist Editorial Team

Silodosin comes with serious risks if you don't take it as prescribed.

If You Don’t Take It at All or Stop Taking It

If you don’t take or stop taking silodosin, you may have increased symptoms of BPH. If you stop or forget to take this medication for several days, talk with your doctor before starting again.

If You Take Too Much

You may experience low blood pressure, especially when you stand up from sitting or lying down. Symptoms may include:

  • feeling dizzy or lightheaded
  • fainting
  • weakness
  • blurry vision
  • confusion

Call your doctor or get emergency medical help right away if you think you’ve taken too much.

What To Do If You Miss a Dose

If you miss a dose, take it as soon as you can. However, if it’s just a few hours until your next dose, skip the missed dose.

Never try to catch up by taking two capsules at once. This could result in toxic side effects.

How To Tell If the Drug is Working

You may be able to tell this drug is working if your symptoms improve. You may have an easier time urinating.

Silodosin is a long-term drug treatment.

Important Considerations for Taking Silodosin

Silodosin should be taken with a meal

Taking silodosin on an empty stomach may increase your risk for side effects, such as a drop in blood pressure when rising from sitting or lying down (orthostatic hypotension).

You can open the capsule if you can’t swallow it whole

If you have difficulty swallowing pills and capsules, you can open the silodosin capsule carefully and sprinkle the powder inside on a tablespoonful of applesauce. Swallow the applesauce within 5 minutes without chewing. Drink an 8-ounce glass of cool water to make sure you completely swallowed the powder. The applesauce shouldn’t be hot and it should be soft enough to be swallowed without chewing. Don’t store any of this silodosin powder/applesauce mixture for future use.

Store in temperatures from 59–86°F (15–30°C)

Keep it away from light and high temperatures.

Keep your drugs away from areas where they could get wet, such as bathrooms. Store them away from moisture and damp locations.

Travel

When traveling with your medication:

  • Always carry it with you or in your carry-on bag.
  • Don’t worry about airport X-ray machines. They can’t hurt this medication.
  • You may need to show your pharmacy’s preprinted label to identify the medication. Keep the original prescription-labeled box with you when traveling.

Clinical monitoring

Prostate-specific antigen blood test: The symptoms of BPH and prostate cancer may be similar. Your doctor may perform an exam and a blood test called a prostate specific antigen (PSA) to make sure you don’t have prostate cancer before prescribing silodosin.

Blood pressure: You doctor may check to see if your blood pressure is low (hypotension). If you have low blood pressure, taking silodosin may lower your blood pressure even more and may not be safe for you to take.

Your diet

To help reduce the symptoms of benign prostatic hyperplasia (BPH), your doctor may instruct you to limit the amount of fluid you drink at night and reduce the amount of alcohol and caffeine you drink.

Insurance

Many insurance companies will require a prior authorization before they approve the prescription and pay for silodosin.

Are There Any Alternatives?

There are other drugs available to treat your condition. Some may be more suitable for you than others. Talk to your doctor about possible alternatives.

What does the pill look like?

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How Much Does silodosin Cost?

Oral capsule
We've partnered with GoodRX so you can compare prices and save money on your next prescription. Check out the lowest cash prices below and enter your zip code to find the best deal near you.

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Lowest price for silodosin

Membership warehouse $199.15
Kroger Pharmacy $199.91
Publix $199.96
These represent the lowest cash prices for silodosin and may be lower than your insurance.

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Content developed in collaboration with University of Illinois-Chicago, Drug Information Group

Medically reviewed by Creighton University, Center for Drug Information and Evidence-Based Practice on July 20, 2015

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.

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