Description and Brand Names

Drug information provided by: Merative, Micromedex®

US Brand Name

  1. Rapaflo

Descriptions


Silodosin is used to treat signs and symptoms of an enlarged prostate gland, which is also known as benign enlargement of the prostate (benign prostatic hyperplasia or BPH). Benign enlargement of the prostate is a problem that can occur in men as they get older. The prostate gland is located below the bladder. As the prostate gland gets larger, certain muscles in the gland may become tight and get in the way of the tube that drains urine from the bladder. This can cause problems in urinating, such as a need to urinate often, a weak stream when urinating, or a feeling of not being able to empty the bladder completely.

Silodosin helps relax the muscles in the prostate and in the opening to the bladder. This may help increase the flow of urine or decrease the symptoms.

This medicine is usually given only to men. It is not normally given to women or children.

This medicine is available only with your doctor's prescription.

This product is available in the following dosage forms:

  • Capsule

Before Using

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Silodosin is not indicated for use in the pediatric population. Safety and efficacy have not been established.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of silodosin in the elderly. However, elderly patients are more likely to have unwanted effects (eg, orthostatic hypotension), which may require caution in patients receiving silodosin.

Breastfeeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Drug Interactions

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

  • Atazanavir
  • Boceprevir
  • Clarithromycin
  • Cobicistat
  • Idelalisib
  • Indinavir
  • Itraconazole
  • Ketoconazole
  • Nefazodone
  • Nelfinavir
  • Nirmatrelvir
  • Ritonavir
  • Saquinavir
  • Telithromycin

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Alfuzosin
  • Bunazosin
  • Carbamazepine
  • Cyclosporine
  • Dapiprazole
  • Doxazosin
  • Melphalan
  • Moxisylyte
  • Phenoxybenzamine
  • Phentolamine
  • Prazosin
  • Simeprevir
  • Tamsulosin
  • Terazosin
  • Tolazoline
  • Trimazosin
  • Urapidil
  • Vardenafil

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Sildenafil
  • Tadalafil

Other Interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Hypotension (low blood pressure)—Use with caution. May make this condition worse.
  • Kidney disease, moderate—Use with caution. The effects of this medicine may be increased because of slower removal from the body.
  • Kidney disease, severe or
  • Liver disease, severe—Should not be used in patients with these conditions.

Proper Use

Take this medicine only as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.

It is best to take this medicine with a meal.

If you have trouble swallowing the capsule, you may open the capsule and sprinkle the powder into a small amount (tablespoonful) of applesauce. Swallow this mixture right away (within 5 minutes) without chewing. Drink a glass of cool water to make sure you swallow all of the medicine.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (capsules):
    • For benign prostatic hyperplasia (BPH):
      • Adults—8 milligrams (mg) once a day.
      • Children—Use is not recommended.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Precautions

It is very important that your doctor check your progress at regular visits for any unwanted effects that may be caused by this medicine.

Do not use this medicine if you are also taking clarithromycin (Biaxin®), ketoconazole (Nizoral®), itraconazole (Sporanox®), or ritonavir (Norvir®). Using these medicines together may cause serious unwanted effects.

Dizziness, lightheadedness, or fainting may occur after you take this medicine, especially when you get up from a lying or sitting position. Getting up slowly may help lessen this problem. If you feel dizzy, lie down so you do not faint. Then sit for a few moments before standing to prevent the dizziness from returning.

This medicine may cause some people to become dizzy or less alert than they are normally. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.

Benign prostatic hyperplasia can have the same symptoms as prostate cancer. They may also often occur together. Your doctor may test for the presence of the cancer before you start using this medicine.

Tell your eye doctor (ophthalmologist) that you have used or are using this medicine before cataract surgery or any other eye procedure. This medicine may cause a serious eye problem called Intraoperative Floppy Iris Syndrome (IFIS).

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Less common

  1. Chills
  2. cold sweats
  3. confusion
  4. dizziness
  5. dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position

Incidence not known

  1. Clay-colored stools
  2. dark urine
  3. fever
  4. headache
  5. hives, itching, rash
  6. loss of appetite
  7. nausea
  8. pinpoint red or purple spots on the skin
  9. skin blisters
  10. stomach pain
  11. unpleasant breath odor
  12. unusual tiredness or weakness
  13. vomiting of blood
  14. yellow eyes or skin

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  1. Change or problem with discharge of semen

Less common

  1. Diarrhea
  2. muscle aches
  3. sore throat
  4. stuffy or runny nose

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Portions of this document last updated: March 01, 2024

Original article: https://www.mayoclinic.org/drugs-supplements/silodosin-oral-route/description/drg-20072436