1 What is Rapaflo?

Brand: Rapaflo

Generic: Silodosin

Rapaflo relaxes your prostate muscles thus facilitating the flow of urine.

Your doctor prescribes you this medicine if you have an enlarged prostate, also known as benign enlargement of the prostate (benign prostatic hyperplasia or BPH). It is available in capsule form.

2 What to Know Before Using

Before using Rapaflo, you must know all about the risks and complications associated with it. Together with your doctor, you can decide whether the medication will do you more goods than the harms.

Here are some factors to be considered before deciding to use this medicine:

Allergies: Inform your doctor about the allergies you have, such as to this medication, other medications, or to foods, dyes, or preservatives.

Pediatric: Not indicated for use in children.

Pregnancy: Not indicated for use in females.

Breastfeeding: Not indicated for use in females.

Geriatric: It may be used in elderly after adjusting the doses.

Drug Interactions: Taking two medicines together can be harmful due to possible interactions. In other cases, even if there is a possible interaction between two medicines your doctor may advise you to take them together after adjusting the dose or issuing precautions.

Here is a list of the medicines which in general are not recommended to be used with silodosin.

Inform your doctor if you are using any of these medicines:

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

Though usually not recommended, your doctor may decide, after adjusting dose or frequency of one or both medicines, to use this medicine with any of the following medicines:

  • Cyclosporine
  • Eliglustat
  • Lomitapide
  • Nilotinib
  • Simeprevir
  • Tocophersolan

Rarely and only when absolutely needed, this medicine may be used with the following medicines even if using them together may put you at risk of certain side effects.

In such cases, you may have to take the adjusted dose or change the frequency of intake.

  • Sildenafil
  • Tadalafil
  • Vardenafil

Other Interactions: Taking your medicine together with certain foods or items such as alcohol or tobacco may cause undesirable interactions. Talk to your doctor to know if using this medicine with food, alcohol, or tobacco is safe.

Inform your doctor about the following conditions, if any:

  • Hypotension (low blood pressure): Use cautiously.
  • Kidney disease, moderate: Use cautiously.
  • Severe kidney or liver impairment: Do not use silodosin.

3 Proper Usage

To use Rapaflo properly, you must follow all instructions given by your doctor. Here are some points to consider:

  • Follow your doctor’s instructions and do not take more, less, more frequently or for a longer duration than recommended.
  • For better results, take silodosin with a meal.

Dosing: For best results, follow your doctor to know what amount of medicine you should take in a single dose.

The doses of a medicine can differ according to the conditions for which it is being prescribed. Remember your doses can differ. Consult your doctor if you have anything to ask.

The doses of capsules are:

For benign prostatic hyperplasia (BPH):

  • Adults: A single once a day dose of 4 to 8 milligrams (mg).
  • Children: Not indicated for use in children.

Missed Dose: Take your missed dose once you remember but avoid it if it’s time to take your next dose, and follow your normal dosing schedule.

Avoid taking double doses to make up for the missed dose. Do not miss more than a dose. If you do, call your doctor before restarting it.


  • Store in a closed container at room temperature.
  • Keep away from heat, moisture, and direct light.
  • Do not freeze.
  • Keep away from children.
  • Discard any unused or expired medicines.

4 Precautions to Take

Before using Rapaflo, there are some precautions you must take. Your progress should be regularly monitored to determine if you are responding to the treatment or have undesirable side effects. Remember:

Do not take silodosin together with clarithromycin, ketoconazole, itraconazole, or ritonavir.

You may feel dizzy or even faint while suddenly standing from a lying or sitting position. Therefore, do not suddenly change the position to avoid fainting.

Take special care while driving or using machines, as it might cause dizziness or drowsiness.

Using this medicine before or during cataract surgery has been linked to a serious eye condition known as Intraoperative Floppy Iris Syndrome (IFIS). Therefore, inform your ophthalmologist about your intake of silodosin if you are planning for a cataract surgery.

Consult your doctor before taking any prescription or nonprescription medicines and herbal or vitamin supplements.

5 Potential Side Effects

As with many medications, there are several potential side effects associated with Rapaflo.

Consult your doctor immediately if you experience any of the following side effects:

Less common:

  • Chills
  • Sweating
  • Confusion
  • Dizziness
  • Dizziness or fainting while suddenly standing from a lying or sitting position

Incidence not known: 

  • Abdominal pain
  • Pale stools
  • Dark concentrated urine
  • Fever
  • Headache
  • Decreased appetite
  • Nausea
  • Red or purple dots on the skin
  • Rash
  • Foul smelling breath
  • Excessive tiredness
  • Bloody vomit
  • Yellowish eyes or skin

Mild and non-serious side effects usually go away on their own without requiring medical intervention. You may also ask your doctor to learn more about how you may prevent or reduce the side effects.

Talk to your doctor if the side effects persist or worry you, including:

More common:

  • Ejaculatory problems

Less common:

The side effects of the medicine are not limited to the ones listed above. Call your doctor immediately if you experience any side effects that are uncommon or worry you. To report side effects to the FDA, contact at 1-800-FDA-1088.

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