Trade Names:Rapaflo- Capsules 4 mg- Capsules 8 mg
Selectively blocks postsynaptic alpha-1 adrenoreceptors located in the prostate, bladder base, prostatic capsule, and prostatic urethra.
AUC is 373.4 ng•h/mL. C max is 61.6 ng/mL. T max is 2.6 h. Absolute bioavailability is about 32%.
Vd is 49.5 L. Approximately 97% is protein bound.
Extensively metabolized through glucuronidation, alcohol and aldehyde dehydrogenase, and CYP3A4 pathways. The major metabolite is pharmacologically active.
Half-life of silodosin is 13.3 h, and that of the major metabolite is about 24 h. Excretion is 54.9% in feces and 33.5% in the urine.
AUC, C max , and elimination half-life are increased in patients with moderate renal impairment.Hepatic Function Impairment
Pharmacokinetics not altered in patients with moderate hepatic impairment. Patients with severe hepatic impairment have not been studied.Elderly
Exposure and elimination half-life are approximately 15% and 20%, respectively, more in subjects with a mean age of 69 yr compared with subjects with a mean age of 24 yr.
Treatment of signs and symptoms of benign prostatic hyperplasia (BPH).
Severe renal impairment (CrCl less than 30 mL/min); severe hepatic impairment (Child-Pugh score 10 or more); coadministration with strong CYP3A4 inhibitors (eg, clarithromycin; itraconazole, ketoconazole, ritonavir).
PO 8 mg once daily with a meal.Dose ModificationAdults
PO Renal impairment (CrCl 30 to 50 mL/min): 4 mg once daily with a meal.
Store at 59° to 86°F. Protect from light and moisture.
Additive pharmacologic effects and adverse reactions may occur. Avoid coadministration with silodosin.Antihypertensives
Use with caution. The risk of dizziness and orthostatic hypotension may be increased.Moderate CYP3A4 inhibitors (eg, diltiazem, erythromycin, verapamil)
Silodosin plasma concentrations may be elevated, increasing the pharmacologic effects and adverse reactions. Use with caution.Phosphodiesterase type 5 inhibitors (eg, sildenafil, tadalafil)
The risk of dizziness and orthostatic reactions may be increased.Strong CYP3A4 inhibitors (eg, itraconazole, ketoconazole, ritonavir)
Silodosin plasma concentrations may be elevated, increasing the pharmacologic effects and adverse reactions. Coadministration with silodosin is contraindicated.Strong P-glycoprotein inhibitors (eg, cyclosporine)
Silodosin exposure may be increased. Coadministration with silodosin is not recommended.
None well documented.
Orthostatic hypotension (3%).
Dizziness (3%); headache (2%); asthenia, insomnia (1% to 2%).
Purpura, toxic skin eruption (postmarketing).
Nasal congestion, nasopharyngitis (2%); rhinorrhea (1% to 2%).
Retrograde ejaculation (28%); increased prostate-specific antigen (1% to 2%).
Impaired hepatic function associated with increased transaminase values, jaundice (postmarketing).
Sinusitis (1% to 2%).
Abdominal pain (1% to 2%).
Prior to starting therapy, examine patients thought to have BPH for carcinoma of the prostate.
Category B .
No information provided.
Safety and efficacy not established.
Risk of orthostatic hypotension may be increased.
Plasma concentrations were approximately 3-fold higher and the half-life was prolonged 2-fold in individuals with moderate renal impairment. Use with caution and in reduced dose in patients with moderate renal impairment.
Contraindicated in individuals with severe hepatic impairment. No dosage adjustments are needed in patients with mild or moderate hepatic impairment.
Caution patients about driving, operating machinery, or performing hazardous tasks when initiating therapy.
Intraoperative floppy iris syndrome has been reported during cataract surgery in patients receiving or previously treated with alpha-1 blockers.
Postural hypotension, with or without symptoms, may occur at the beginning of treatment.
Rule out before starting therapy.
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