Silodosin

Silodosin is a selective antagonist of post-synaptic alpha-1 adrenoreceptors, which are located in the human prostate, bladder base, bladder neck, prostatic capsule, and prostatic urethra. Blockade of these alpha-1 adrenoreceptors can cause smooth muscle in these tissues to relax, resulting in an improvement in urine flow and a reduction in BPH symptoms.

• Silodosin capsules, an alpha-1 adrenergic receptor antagonist, is indicated for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH). Silodosin capsule is not indicated for the treatment of hypertension.ICD-10: I10, N40.0

• Patients with severe renal impairment [Creatinine Clearance (CCr < 30 mL/min)]. ( 4 ) Patients with severe hepatic impairment (Child-Pugh score ≥ 10).contraindicated

8 mg capsules taken orally once daily with a meal. ( 2.1 ) 4 mg capsules taken orally once daily with a meal for those with moderate renal impairment [Creatinine Clearance (CCr) 30 mL/min to 50 mL/min]. ( 2.2 ) 2.1 Dosing Information The recommended dose is 8 mg orally once daily with a meal. Patients who have difficulty swallowing pills and capsules may carefully open the silodosin capsule and sprinkle the powder inside on a tablespoonful of applesauce. The applesauce should be swallowed immediately (within 5 minutes) without chewing and followed with an 8 oz glass of cool water to ensure complete swallowing of the powder. The applesauce used should not be hot, and it should be soft enough to be swallowed without chewing. Any powder/applesauce mixture should be used immediately (within 5 minutes) and not stored for future use. Subdividing the contents of a silodosin capsule is not recommended [see CLINICAL PHARMACOLOGY ( 12.3 )] . 2.2 Dosage Adjustment in Special Populations Renal impairment: Silodosin capsule is contraindicated in patients with severe renal impairment (CCr < 30 mL/min). In patients with moderate renal impairment (CCr 30 mL/min to 50 mL/min), the dose should be reduced to 4 mg once daily taken with a meal. No dosage adjustment is needed in patients with mild renal impairment (CCr 50 mL/min to 80 mL/min) [see CONTRAINDICATIONS ( 4 ), WARNINGS AND PRECAUTIONS ( 5.2 ), USE IN SPECIFIC POPULATIONS ( 8.6 ) and CLINICAL PHARMACOLOGY ( 12.3 )].

Postural hypotension, with or without symptoms (e.g., dizziness), may develop when beginning silodosin treatment. ( 5.1 ) In patients with moderate renal impairment, silodosin dose should be reduced to 4 mg once daily. ( 5.2 ) Silodosin should not be used in combination with other alpha-blockers. ( 5.5 ) Examine patients thought to have BPH prior to starting therapy with silodosin to rule out the presence of carcinoma of the prostate. ( 5.6 ) Inform patients planning cataract surgery to notify their ophthalmologist that they are taking silodosin because of the possibility of Intraoperative Floppy Iris Syndrome (IFIS). ( 5.7 ) 5.1 Orthostatic Effects Postural hypotension, with or without symptoms (e.g., dizziness) may develop when beginning silodosin treatment. As with other alpha-blockers, there is potential for syncope. Patients should be cautioned about driving, operating machinery, or performing hazardous tasks when initiating therapy [ see ADVERSE REACTIONS ( 6 ), USE IN SPECIFIC POPULATIONS ( 8.5 ), CLINICAL PHARMACOLOGY ( 12.2 ), and PATIENT COUNSELING INFORMATION ( 17 ) ] . 5.2 Renal Impairment In a clinical pharmacology study, plasma concentrations (AUC and C max ) of silodosin were approximately three times higher in subjects with moderate renal impairment compared with subjects with normal renal function, while half-lives of silodosin doubled in duration. The dose of silodosin should be reduced to 4 mg in patients with moderate renal impairment.

Most common adverse reactions (incidence ≥ 2%) are retrograde ejaculation, dizziness, diarrhea, orthostatic hypotension, headache, nasopharyngitis, and nasal congestion. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Lupin Pharmaceuticals, Inc. at 1-800-399-2561 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 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 silodosin daily. This includes 486 patients exposed for 6 months and 168 patients exposed for 1 year. The population was 44 years 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 silodosin and 457 patients were administered placebo. At least one treatment-emergent adverse reaction was reported by 55.2% of silodosin treated patients (36.8% for placebo treated). The majority (72.1%) of adverse reactions for the silodosin treated patients (59.8% for placebo treated) were qualified by the investigator as mild.

Renal impairment: Dose adjustment in moderate disease ( 2.2 ). Contraindicated in severe renal disease. ( 4 ) Hepatic impairment: Contraindicated in severe disease. ( 4 ) 8.1 Pregnancy Risk Summary Silodosin is not indicated for use in females. 8.2 Lactation Silodosin is not indicated for use in females. 8.3 Females and Males of Reproductive Potential Infertility Males Possible effects on male fertility could be observed based on findings in rats at exposures that were at least two times higher than at the MRHD (based on AUC). These findings may be reversible, and the clinical relevance is unknown [see NONCLINICAL TOXICOLOGY (13.1)]. 8.4 Pediatric Use Silodosin is not indicated for use in pediatric patients. Safety and effectiveness in pediatric patients have not been established. 8.5 Geriatric Use In double-blind, placebo-controlled, 12-week clinical studies of silodosin, 259 (55.6%) were under 65 years of age, 207 (44.4%) patients were 65 years of age and over, while 60 (12.9%) patients were 75 years of age and over. Orthostatic hypotension was reported in 2.3% of silodosin patients < 65 years of age (1.2% for placebo), 2.9% of silodosin patients ≥ 65 years of age (1.9% for placebo), and 5.0% of patients ≥ 75 years of age (0% for placebo).

Metabolism

The pharmacokinetics of silodosin have been evaluated in adult male subjects with doses ranging from 0.1 mg to 24 mg per day. The pharmacokinetics of silodosin are linear throughout this dosage range.

Silodosin was evaluated at doses of up to 48 mg/day in healthy male subjects. The dose-limiting adverse event was postural hypotension. Should overdose of silodosin lead to hypotension, support of the cardiovascular system is of first importance. Restoration of blood pressure and normalization of heart rate may be accomplished by maintaining the patient in the supine position. If this measure is inadequate, administration of intravenous fluid should be considered. If necessary, vasopressors could be used, and renal function should be monitored and supported as needed. Dialysis is unlikely to be of significant benefit since silodosin is highly (97%) protein bound.

• Dec 3, 2018ANDAANDA210687Msn
• Dec 3, 2018ANDAANDA211060Ajanta Pharma Ltd
• Dec 3, 2018ANDAANDA209745Amneal Pharms Co
• Dec 3, 2018ANDAANDA211166Macleods Pharms Ltd
• Dec 3, 2018ANDAANDA206541Lupin
• Dec 10, 2018ANDAANDA210626Aurobindo Pharma Ltd
• Nov 22, 2019ANDAANDA211731Alembic
• Feb 14, 2020ANDAANDA204793Hetero Labs Ltd V

1. 1Off Label Use1704.5%
2. 2Diarrhoea1514.0%
3. 3Fatigue1463.8%
4. 4Drug Ineffective1433.7%
5. 5Dizziness1383.6%
6. 6Acute Kidney Injury1233.2%
7. 7Anaemia1223.2%
8. 8Asthenia1203.1%
9. 9Pyrexia1193.1%
10. 10Drug Interaction1183.1%
11. 11Hypotension1173.1%
12. 12Urinary Retention1173.1%
13. 13Fall1122.9%
14. 14Death1092.9%
15. 15Dyspnoea1082.8%

The 10 most recently updated of 52 ClinicalTrials.gov registrations naming Silodosin as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• Silodosin for Urinary Symptoms in Female Patients With Multiple Sclerosis
  Recruiting · Phase 4 · Interventional · 60 enrolled · Atlantic Health System
  NCT07614321updated 2026-05-29
• Silodosin vs Tamsulosin for LUTS Due to BPH: A Randomized Crossover Trial
  Not yet recruiting · Phase 4 · Interventional · 140 enrolled · Ain Shams University
  NCT07467343updated 2026-03-16
• Effect of Preoperative Alpha-blockers on Successful Insertion Ureteral Access Sheath and Reduce Ureteral Injury in Non-prestented Patients During RIRS. Assessment of Factors for Successful Ureteral Access Sheath Insertion.
  Completed · Observational · 140 enrolled · St. Luke's Clinical Hospital, Russia
  NCT07202923updated 2025-11-24
• Sildosin as a Male Contraceptive Non Hormonal
  Not yet recruiting · Phase 1 · Interventional · 200 enrolled · Benha University
  NCT07195097updated 2025-09-26
• A Phase III Clinical Study of H077 Sustained-Release Tablets Compared With Silodosin Capsules in the Treatment of Benign Prostatic Hyperplasia
  Not yet recruiting · Phase 3 · Interventional · 728 enrolled · Shanghai Huilun Pharmaceutical Co., Ltd.
  NCT07146386updated 2025-08-28
• The Efficacy and Safety of Qianweitai (Silodosin Capsule) Versus Tamsulosin in the Treatment of BPH
  Completed · Phase 4 · Interventional · 110 enrolled · Shanghai Huilun Pharmaceutical Co., Ltd.
  NCT07134907updated 2025-08-21
• Medical Stone Expulsive Therapy for Acutely Obstructed Ureteric Calculi
  Completed · Phase 4 · Interventional · 240 enrolled · Getz Pharma
  NCT05977647updated 2025-08-20
• Comparative Evaluation of Safety and Efficacy of Dapoxetine, Silodosin, and Citalopram in the Management of Premature Ejaculation
  Completed · Phase 4 · Interventional · 450 enrolled · Beni-Suef University
  NCT07113145updated 2025-08-08
• On-demand Silodosin 4mg vs Dapoxetine 60mg in Treatment of Primary Premature Ejaculation
  Completed · Phase 2 · Phase 3 · Interventional · 95 enrolled · Benha University
  NCT07081659updated 2025-07-23
• Silodosin in Facilitating Flexible Uretroscopy
  Active not recruiting · Interventional · 42 enrolled · Ain Shams University
  NCT07068087updated 2025-07-16

Frequently asked questions

How does Silodosin work?

Silodosin is a selective antagonist of post-synaptic alpha-1 adrenoreceptors, which are located in the human prostate, bladder base, bladder neck, prostatic capsule, and prostatic urethra. Blockade of these alpha-1 adrenoreceptors can cause smooth muscle in these tissues to relax, resulting in an improvement in urine flow and a reduction in BPH symptoms.

What is Silodosin used for?

According to FDA labeling, Silodosin carries indications including: Silodosin capsules, an alpha-1 adrenergic receptor antagonist, is indicated for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH). Silodosin capsule is not indicated for the treatment of hypertension.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Silodosin?

Silodosin is classified as Alpha-adrenoreceptor antagonists, alpha-Adrenergic Blocker, Adrenergic alpha-Antagonists, Adrenergic alpha1-Antagonists, Cytochrome P450 3A4 Inhibitors, Decreased Bladder Sphincter Tone, Decreased Urethra Smooth Muscle Tone.

What are the brand names for Silodosin?

Silodosin is marketed under brand names including Rapaflo.

What are the contraindications for Silodosin?

Silodosin labeling lists contraindications including: Patients with severe renal impairment [Creatinine Clearance (CCr < 30 mL/min)]. ( 4 ) Patients with severe hepatic impairment (Child-Pugh score ≥ 10).. Always consult the full prescribing information and a clinician.