Generic name: silodosin [ SIL-oh-DOE-sin ]
Brand name: Rapaflo
Dosage form: oral capsule (4 mg; 8 mg)
Drug class: Alpha-adrenoreceptor antagonists

Medically reviewed by Drugs.com on Jun 1, 2023. Written by Cerner Multum.

What is silodosin?

Silodosin is an alpha-blocker that is used to improve urination in men with benign prostatic hyperplasia (enlarged prostate).

Silodosin may also be used for purposes not listed in this medication guide.

Silodosin side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have severe dizziness, or if you feel like you might pass out.

Silodosin may cause dizziness or fainting, especially when you first start taking it. You may feel very dizzy when you first wake up or get up too fast from a sitting or lying position.

Common side effects of silodosin may include:

• dizziness, feeling like you might pass out;

• headache;

• diarrhea;

• abnormal ejaculation; or

• stuffy nose, sinus pain.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Warnings

Tell your doctor about all your other medicines. Some drugs should not be used with silodosin.

Related/similar drugs

tamsulosin, finasteride, tadalafil, Flomax, prazosin, Cialis

Before taking this medicine

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

• severe liver disease; or

• severe kidney disease.

Some drugs should not be used with silodosin. Your treatment plan may change if you also use:

• nefazodone;

• an antibiotic--clarithromycin, telithromycin;

• antifungal medicine--itraconazole, ketoconazole, posaconazole, voriconazole; or

• antiviral medicine for HIV or hepatitis C--boceprevir, cobicistat, dasabuvir, elvitegravir, indinavir, lopinavir/ritonavir, nelfinavir, ombitasvir, paritaprevir saquinavir, telaprevir, or tipranavir.

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.

Silodosin can affect your pupils. If you need eye surgery, tell the surgeon about your use of silodosin, even if you no longer take it.

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

Not approved for use by anyone younger than 18 years old.

How should I take silodosin?

Your doctor may test your prostate specific antigen (PSA) to check for prostate cancer before you take silodosin.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

Take once daily with a meal.

If you cannot swallow a capsule whole, open it and mix the medicine with applesauce. Swallow the mixture right away without chewing.

Your blood pressure may get too low during prolonged illness. Call your doctor if you are sick with vomiting or diarrhea.

Your blood pressure will need to be checked often.

Store at room temperature away from moisture, heat, and light.

Silodosin dosing information

Usual Adult Dose for Benign Prostatic Hyperplasia:

8 mg orally once a day with a meal

Comments: Patients who have difficulty swallowing may open the capsule and sprinkle the powder on a tablespoonful of applesauce. The applesauce should not be hot, and should be soft enough to be swallowed within 5 minutes without chewing and followed with 8 ounces of cool water.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking silodosin?

Avoid driving or hazardous activity until you know how silodosin will affect you. Your reactions could be impaired.

What other drugs will affect silodosin?

Tell your doctor about all your current medicines. Many drugs can increase your risk of very low blood pressure while taking silodosin, especially:

• medicines similar to silodosin (alfuzosin, doxazosin, prazosin, tamsulosin, or terazosin);

• heart or blood pressure medication; or

• sildenafil (Viagra) and other erectile dysfunction medicines.

This list is not complete and many other drugs may affect silodosin. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer

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