RAPAFLO® (silodosin) Capsules

(description)

Clinical pharmacology

Indications and usage

Contraindications

Precautions

Adverse reactions

Dosage and administration

How supplied

Reference

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HIGHLIGHTS OF PRESCRIBING INFORMATION
RAPAFLO® (silodosin) capsules
Revised: November 2009
Rx only

17376121109

These highlights do not include all the information needed to use RAPAFLO® safely and effectively. See full prescribing information for RAPAFLO.

RAPAFLO® (silodosin) capsule for oral use
Initial U.S. Approval: 2008

DESCRIPTION
RAPAFLO is the brand name for silodosin, a selective antagonist of alpha-1 adrenoreceptors. The chemical name of silodosin is 1-(3-Hydroxypropyl)-5-[(2R)-2-({2-[2-(2,2,2-trifluoroethoxy)phenoxy]ethyl}amino)propyl]-2,3-dihydro-1H-indole-7-carboxamide and the molecular formula is C25H32F3N3O4 with a molecular weight of 495.53

Clinical pharmacology

CLINICAL PHARMACOLOGY

Mechanism of Action
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.

An in vitro study examining binding affinity of silodosin to the three subtypes of the alpha-1 adrenoreceptors (alpha-1A, alpha-1B, and alpha-1D) was conducted. The results of the study demonstrated that silodosin binds with high affinity to the alpha-1A subtype.

Indications and usage

INDICATIONS AND USAGE
RAPAFLO, an alpha-1 adrenergic receptor antagonist, is indicated for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH).
RAPAFLO is not indicated for the treatment of hypertension.

Contraindications

CONTRAINDICATIONS
--Patients with severe renal impairment [Creatinine Clearance (CCr < 30 mL/min)].
--Patients with severe hepatic impairment (Child-Pugh score >/= 10).
--Concomitant administration with strong Cytochrome P450 3A4 (CYP3A4) inhibitors (e.g., ketoconazole, clarithromycin, itraconazole, ritonavir).

Precautions

WARNINGS AND PRECAUTIONS
--Postural hypotension, with or without symptoms (e.g., dizziness), may develop when beginning RAPAFLO treatment.
--In patients with moderate renal impairment, RAPAFLO dose should be reduced to 4 mg once daily.
--RAPAFLO should not be used in combination with other alpha-blockers.
--Examine patients thought to have BPH prior to starting therapy with RAPAFLO to rule out the presence of carcinoma of the prostate.
--Inform patients planning cataract surgery to notify their ophthalmologist that they are taking RAPAFLO because of the possibility of Intraoperative Floppy Iris Syndrome (IFIS).

DRUG INTERACTIONS
--Strong P-glycoprotein inhibitors (e.g., cyclosporine): Co-administration may increase plasma silodosin concentration. Concomitant use is not recommended.
--Alpha-blockers: Interactions involving concomitant use have not been determined. However, interactions are expected and concomitant use is not recommended.
--Concomitant use of PDE5 inhibitors with alpha-blockers including Rapaflo can potentially cause symptomatic hypotension.

USE IN SPECIFIC POPULATIONS
--Renal impairment: Dose adjustment in moderate disease . Contraindicated in severe renal disease.
--Hepatic impairment: Contraindicated in severe disease.

Adverse reactions

ADVERSE REACTIONS
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 Watson Pharmaceuticals, Inc. at 1-800-272-5525 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Dosage and administration

DOSAGE AND ADMINISTRATION
8 mg capsules taken orally once daily with a meal.

4 mg capsules taken orally once daily with a meal for those with moderate renal impairment [Creatinine Clearance (CCr) 30-50 mL/min].

How supplied

DOSAGE FORMS AND STRENGTHS
Capsules: 8 mg and 4 mg.

Reference

Package Insert data:
Manufactured by:
Watson Laboratories, Inc.
Corona, CA 92880 USA

Distributed by:
Watson Pharma, Inc.
Morristown, NJ 07962 USA

Under license from:
Kissei Pharmaceutical Co., Ltd.
Nagano, Japan

Address medical inquiries to:
WATSON
Medical Communications
P.O. Box 1953
Morristown, NJ 07962-1953
800-272-5525

For additional information see:
www.rapaflo.com
or call 1-866-RAPAFLO (727-2356)

Rx only

Revised: November 2009

173761-2
S1109

Reference(s)

National Institutes of Health, U.S. National Library of Medicine, DailyMed Database.
Provides access to the latest drug monographs submitted to the Food and Drug Administration (FDA). Please review the latest applicable package insert for additional information and possible updates. A local search option of this data can be found here.