Rapaflo Capsules

Last reviewed on RxList: 1/12/2021
Rapaflo Capsules Side Effects Center

What Is Rapaflo?

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

What Are Side Effects of Rapaflo?

Tell your doctor if you have serious side effects of Rapaflo including:

  • feeling like you might pass out, or
  • an erection that is painful or lasts 4 hours or longer.

Dosage for Rapaflo

The recommended dose of Rapaflo is 8 mg orally once daily with a meal.

What Drugs, Substances, or Supplements Interact with Rapaflo?

Rapaflo may interact with etoconazole, itraconazole, ritonavir, diltiazem, erythromycin, verapamil, cyclosporine, other alpha-blockers, digoxin, sildenafil, tadalafil, or anti-hypertensives. Tell your doctor all medications you are taking.

Rapaflo During Pregnancy and Breastfeeding

Although Rapaflo is not for use in women, this medication is not expected to be harmful to a fetus. If you are a woman using this medication, tell your doctor if you are pregnant or plan to become pregnant during treatment. It is not known whether this medication passes into breast milk, or if it could harm a nursing baby. Consult your doctor if you are breastfeeding.

Additional Information

Our Rapaflo (silodosin) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

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.


Sex-Drive Killers: The Causes of Low Libido See Slideshow
Rapaflo Capsules Consumer Information

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.

  • severe dizziness, or if you feel like you might pass out.

Common side effects may include:

  • dizziness;
  • 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.

Read the entire detailed patient monograph for Rapaflo Capsules (Silodosin Capsules)


Testosterone is a chemical found only in men. See Answer
Rapaflo Capsules Professional Information


Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

In U.S. clinical trials, 897 patients with BPH were exposed to 8 mg RAPAFLO daily. This includes 486 patients exposed for 6 months and 168 patients exposed for 1 year. The population was 44 to 87 years of age, and predominantly Caucasian. Of these patients, 42.8% were 65 years of age or older and 10.7% were 75 years of age or older.

In double-blind, placebo controlled, 12-week clinical trials, 466 patients were administered RAPAFLO and 457 patients were administered placebo. At least one treatment-emergent adverse reaction was reported by 55.2% of RAPAFLO treated patients (36.8% for placebo treated). The majority (72.1%) of adverse reactions for the RAPAFLO treated patients (59.8% for placebo treated) were qualified by the investigator as mild. A total of 6.4% of RAPAFLO treated patients (2.2% for placebo treated) discontinued therapy due to an adverse reaction (treatment-emergent), the most common reaction being retrograde ejaculation (2.8%) for RAPAFLO treated patients. Retrograde ejaculation is reversible upon discontinuation of treatment.

Adverse Reactions Observed In At Least 2% Of Patients

The incidence of treatment-emergent adverse reactions listed in the following table were derived from two 12-week, multicenter, double-blind, placebo-controlled clinical studies of RAPAFLO 8 mg daily in BPH patients. Adverse reactions that occurred in at least 2% of patients treated with RAPAFLO and more frequently than with placebo are shown in Table 1.

Table 1 : Adverse Reactions Occurring in ≥ 2% of Patients in 12-week, Placebo-Controlled Clinical Trials

Adverse ReactionsRAPAFLO
N = 466 n (%)
N = 457 n (%)
Retrograde Ejaculation131 (28.1)4 (0.9)
Dizziness15 (3.2)5 (1.1)
Diarrhea12 (2.6)6 (1.3)
Orthostatic Hypotension12 (2.6)7 (1.5)
Headache11 (2.4)4 (0.9)
Nasopharyngitis11 (2.4)10 (2.2)
Nasal Congestion10 (2.1)1 (0.2)

In the two 12-week, placebo-controlled clinical trials, the following adverse events were reported by between 1% and 2% of patients receiving RAPAFLO and occurred more frequently than with placebo: insomnia, PSA increased, sinusitis, abdominal pain, asthenia, and rhinorrhea. One case of syncope in a patient taking prazosin concomitantly and one case of priapism were reported in the RAPAFLO treatment group.

In a 9-month open-label safety study of RAPAFLO, one case of Intraoperative Floppy Iris Syndrome (IFIS) was reported.

Postmarketing Experience

The following adverse reactions have been identified during post approval use of silodosin. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure:

Skin and subcutaneous tissue disorders: toxic skin eruption, purpura, skin rash, pruritus, and urticaria

Hepatobiliary disorders: jaundice, impaired hepatic function associated with increased transaminase values

Immune system disorders: allergic-type reactions, not limited to skin reactions including swollen tongue and pharyngeal edema resulting in serious outcomes

Read the entire FDA prescribing information for Rapaflo Capsules (Silodosin Capsules)

© Rapaflo Capsules Patient Information is supplied by Cerner Multum, Inc. and Rapaflo Capsules Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

Health Solutions From Our Sponsors