Tamsulosin Hydrochloride

1 INDICATIONS AND USAGE Tamsulosin hydrochloride capsules are indicated for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH) [see Clinical Studies (14)]. Tamsulosin hydrochloride capsules are not indicated for the treatment of hypertension. Tamsulosin hydrochloride capsules are an alpha 1 adrenoceptor antagonist indicated for treatment of the signs and symptoms of benign prostatic hyperplasia (1) Tamsulosin hydrochloride capsules are not indicated for the treatment of hypertension (1)

2 DOSAGE AND ADMINISTRATION Tamsulosin hydrochloride capsules 0.4 mg once daily is recommended as the dose for the treatment of the signs and symptoms of BPH. It should be administered approximately one-half hour following the same meal each day. Tamsulosin hydrochloride capsules should not be crushed, chewed or opened. For those patients who fail to respond to the 0.4 mg dose after 2 to 4 weeks of dosing, the dose of tamsulosin hydrochloride capsules can be increased to 0.8 mg once daily. Tamsulosin hydrochloride capsules 0.4 mg should not be used in combination with strong inhibitors of CYP3A4 (e.g., ketoconazole) [see Warnings and Precautions (5.2)]. If tamsulosin hydrochloride capsules administration is discontinued or interrupted for several days at either the 0.4 mg or 0.8 mg dose, therapy should be started again with the 0.4 mg once-daily dose. 0.4 mg once daily taken approximately one-half hour following the same meal each day. Tamsulosin hydrochloride capsules should not be crushed, chewed or opened. (2) Can be increased to 0.8 mg once daily for patients who fail to respond to the 0.4 mg dose after 2 to 4 weeks of dosing (2) If discontinued or interrupted for several days, therapy should start again with the 0.4 mg once-daily dose (2)

6 ADVERSE REACTIONS The most common adverse events (≥2% of patients and at a higher incidence than placebo) with the 0.4 mg dose or 0.8 mg dose were headache, dizziness, rhinitis, infection, abnormal ejaculation, asthenia, back pain, diarrhea, pharyngitis, chest pain, cough increased, somnolence, nausea, sinusitis, insomnia, libido decreased, tooth disorder, and blurred vision (6.1) To report SUSPECTED ADVERSE REACTIONS, contact XLCare Pharmaceuticals, Inc. at 1-866-495-1995 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical studies are conducted under widely varying conditions, adverse reactions rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice. The incidence of treatment-emergent adverse events has been ascertained from six short-term U.S. and European placebo-controlled clinical trials in which daily doses of 0.1 to 0.8 mg tamsulosin hydrochloride capsules were used. These studies evaluated safety in 1783 patients treated with tamsulosin hydrochloride capsules and 798 patients administered placebo. Table 1 summarizes the treatment-emergent adverse events that occurred in ≥2% of patients receiving either tamsulosin hydrochloride capsules 0.4 mg or 0.8 mg and at an incidence numerically higher than that in the placebo group during two 13-week U.S. trials (US92-03A and US93-01) conducted in 1487 men. Table 1 Treatment-Emergent* Adverse Events Occurring in ≥2% of Tamsulosin Hydrochloride Capsules or Placebo Patients in Two U.S. Short-Term Placebo-Controlled Clinical Studies BODY SYSTEM/ ADVERSE EVENT TAMSULOSIN HYDROCHLORIDE CAPSULES GROUPS PLACEBO 0.4 mg n=502 0.8 mg n=492 n=493 BODY AS WHOLE Headache 97 (19.3%) 104 (21.1%) 99 (20.1%) Infection† 45 (9%) 53 (10.8%) 37 (7.5%) Asthenia 39 (7.8%) 42 (8.5%) 27 (5.5%) Back pain 35 (7%) 41 (8.3%) 27 (5.5%) Chest pain 20 (4%) 20 (4.1%) 18 (3.7%) NERVOUS SYSTEM Dizziness 75 (14.9%) 84 (17.1%) 50 (10.1%) Somnolence 15 (3%) 21 (4.3%) 8 (1.6%) Insomnia 12 (2.4%) 7 (1.4%) 3 (0.6%) Libido decreased 5 (1%) 10 (2%) 6 (1.2%) RESPIRATORY SYSTEM Rhinitis‡ 66 (13.1%) 88 (17.9%) 41 (8.3%) Pharyngitis 29 (5.8%) 25 (5.1%) 23 (4.7%) Cough increased 17 (3.4%) 22 (4.5%) 12 (2.4%) Sinusitis 11 (2.2%) 18 (3.7%) 8 (1.6%) DIGESTIVE SYSTEM Diarrhea 31 (6.2%) 21 (4.3%) 22 (4.5%) Nausea 13 (2.6%) 19 (3.9%) 16 (3.2%) Tooth disorder 6 (1.2%) 10 (2%) 7 (1.4%) UROGENITAL SYSTEM Abnormal ejaculation 42 (8.4%) 89 (18.1%) 1 (0.2%) SPECIAL SENSES Blurred vision 1 (0.2%) 10 (2%) 2 (0.4%) * A treatment-emergent adverse event was defined as any event satisfying one of the following criteria: The adverse event occurred for the first time after initial dosing with double-blind study medication; The adverse event was present prior to or at the time of initial dosing with double-blind study medication and subsequently increased in severity during double-blind treatment; or The adverse event was present prior to or at the time of initial dosing with double-blind study medication, disappeared completely, and then reappeared during double-blind treatment. † Coding preferred terms also include cold, common cold, head cold, flu, and flu-like symptoms. ‡ Coding preferred terms also include nasal congestion, stuffy nose, runny nose, sinus congestion, and hay fever. Signs and Symptoms of Orthostasis In the two U.S. studies, symptomatic postural hypotension was reported by 0.2% of patients (1 of 502) in the 0.4 mg group, 0.4% of patients (2 of 492) in the 0.8 mg group, and by no patients in the placebo group. Syncope was reported by 0.2% of patients (1 of 502) in the 0.4 mg group, 0.4% of patients (2 of 492) in the 0.8 mg group, and 0.6% of patients (3 of 493) in the placebo group. Dizziness was reported by 15% of patients (75 of 502) in the 0.4 mg group, 17% of patients (84 of 492) in the 0.8 mg group, and 10% of patients (50 of 493) in the placebo group. Vertigo was reported by 0.6% of patients (3 of 502) in the 0.4 mg group, 1% of patients (5 of 492) in the 0.8 mg group, and by 0.6% of patients (3 of 493) in the placebo group. Multiple testing for orthostatic hypotension was conducted in a number of studies. Such a test was considered positive if it met one or more of the following criteria: (1) a decrease in systolic blood pressure of ≥20 mmHg upon standing from the supine position during the orthostatic tests; (2) a decrease in diastolic blood pressure ≥10 mmHg upon standing, with the standing diastolic blood pressure <65 mmHg during the orthostatic test; (3) an increase in pulse rate of ≥20 bpm upon standing with a standing pulse rate ≥100 bpm during the orthostatic test; and (4) the presence of clinical symptoms (faintness, lightheadedness/lightheaded, dizziness, spinning sensation, vertigo, or postural hypotension) upon standing during the orthostatic test. Following the first dose of double-blind medication in Study 1, a positive orthostatic test result at 4 hours post dose was observed in 7% of patients (37 of 498) who received tamsulosin hydrochloride capsules 0.4 mg once daily and in 3% of the patients (8 of 253) who received placebo. At 8 hours post dose, a positive orthostatic test result was observed for 6% of the patients (31 of 498) who received tamsulosin hydrochloride capsules 0.4 mg once daily and 4% (9 of 250) who received placebo (Note: patients in the 0.8 mg group received 0.4 mg once daily for the first week of Study 1). In Studies 1 and 2, at least one positive orthostatic test result was observed during the course of these studies for 81 of the 502 patients (16%) in the tamsulosin hydrochloride capsules 0.4 mg once-daily group, 92 of the 491 patients (19%) in the tamsulosin hydrochloride capsules 0.8 mg once-daily group, and 54 of the 493 patients (11%) in the placebo group. Because orthostasis was detected more frequently in tamsulosin hydrochloride capsule-treated patients than in placebo recipients, there is a potential risk of syncope [see Warnings and Precautions (5.1)]. Abnormal Ejaculation Abnormal ejaculation includes ejaculation failure, ejaculation disorder, retrograde ejaculation, and ejaculation decrease. As shown in Table 1, abnormal ejaculation was associated with tamsulosin hydrochloride capsules administration and was dose-related in the U.S. studies. Withdrawal from these clinical studies of tamsulosin hydrochloride capsules because of abnormal ejaculation was also dose-dependent, with 8 of 492 patients (1.6%) in the 0.8 mg group and no patients in the 0.4 mg or placebo groups discontinuing treatment due to abnormal ejaculation. Laboratory Tests No laboratory test interactions with tamsulosin hydrochloride capsules are known. Treatment with tamsulosin hydrochloride capsules for up to 12 months had no significant effect on prostate-specific antigen (PSA). 6.2 Postmarketing Experience The following adverse reactions have been identified during post-approval use of tamsulosin hydrochloride capsules. 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. Decisions to include these reactions in labeling are typically based on one or more of the following factors: (1) seriousness of the reaction, (2) frequency of reporting, or (3) strength of causal connection to tamsulosin hydrochloride capsules. Allergic-type reactions such as skin rash, urticaria, pruritus, angioedema, and respiratory symptoms have been reported with positive rechallenge in some cases. Priapism has been reported rarely. Infrequent reports of dyspnea, palpitations, hypotension, atrial fibrillation, arrhythmia, tachycardia, skin desquamation including reports of Stevens-Johnson syndrome, erythema multiforme, dermatitis exfoliative, constipation, vomiting, dry mouth, visual impairment, and epistaxis have been received during the postmarketing period. During cataract and glaucoma surgery, a variant of small pupil syndrome known as Intraoperative Floppy Iris Syndrome (IFIS) has been reported in association with alpha 1 blocker therapy [see Warnings and Precautions (5.5)].

12.3 Pharmacokinetics The pharmacokinetics of tamsulosin hydrochloride have been evaluated in adult healthy volunteers and patients with BPH after single and/or multiple administration with doses ranging from 0.1 mg to 1 mg. Absorption Absorption of tamsulosin hydrochloride from tamsulosin hydrochloride capsules 0.4 mg is essentially complete (>90%) following oral administration under fasting conditions. Tamsulosin hydrochloride exhibits linear kinetics following single and multiple dosing, with achievement of steady-state concentrations by the fifth day of once-a-day dosing. Effect of Food The time to maximum concentration (T max ) is reached by 4 to 5 hours under fasting conditions and by 6 to 7 hours when tamsulosin hydrochloride capsules are administered with food. Taking tamsulosin hydrochloride capsules under fasted conditions results in a 30% increase in bioavailability (AUC) and 40% to 70% increase in peak concentrations (C max ) compared to fed conditions (Figure 1). Figure 1 Mean Plasma Tamsulosin Hydrochloride Concentrations Following Single-Dose Administration of Tamsulosin Hydrochloride Capsules 0.4 mg Under Fasted and Fed Conditions (n=8) The effects of food on the pharmacokinetics of tamsulosin hydrochloride are consistent regardless of whether a tamsulosin hydrochloride capsules are taken with a light breakfast or a high-fat breakfast (Table 2). Table 2 Mean (± S.D.) Pharmacokinetic Parameters Following Tamsulosin Hydrochloride Capsules 0.4 mg Once Daily or 0.8 mg Once Daily with a Light Breakfast, High-Fat Breakfast or Fasted Pharmacokinetic Parameter 0.4 mg QD to healthy volunteers; n=23 (age range 18 to 32 years) 0.8 mg QD to healthy volunteers; n=22 (age range 55 to 75 years) Light Breakfast Fasted Light Breakfast High-Fat Breakfast Fasted C min (ng/mL) 4 ± 2.6 3.8 ± 2.5 12.3 ± 6.7 13.5 ± 7.6 13.3 ± 13.3 C max (ng/mL) 10.1 ± 4.8 17.1 ± 17.1 29.8 ± 10.3 29.1 ± 11 41.6 ± 15.6 C max /C min Ratio 3.1 ± 1 5.3 ± 2.2 2.7 ± 0.7 2.5 ± 0.8 3.6 ± 1.1 T max (hours) 6 4 7 6.6 5 T 1/2 (hours) - - - - 14.9 ± 3.9 AUC τ (ng•hr/mL) 151 ± 81.5 199 ± 94.1 440 ± 195 449 ± 217 557 ± 257 C min = observed minimum concentration C max = observed maximum tamsulosin hydrochloride plasma concentration T max = median time-to-maximum concentration T 1/2 = observed half-life AUCτ = area under the tamsulosin hydrochloride plasma time curve over the dosing interval Distribution The mean steady-state apparent volume of distribution of tamsulosin hydrochloride after intravenous administration to 10 healthy male adults was 16 L, which is suggestive of distribution into extracellular fluids in the body. Tamsulosin hydrochloride is extensively bound to human plasma proteins (94% to 99%), primarily alpha 1 acid glycoprotein (AAG), with linear binding over a wide concentration range (20 to 600 ng/mL). The results of two-way in vitro studies indicate that the binding of tamsulosin hydrochloride to human plasma proteins is not affected by amitriptyline, diclofenac, glyburide, simvastatin plus simvastatin-hydroxy acid metabolite, warfarin, diazepam, propranolol, trichlormethiazide, or chlormadinone. Likewise, tamsulosin hydrochloride had no effect on the extent of binding of these drugs. Metabolism There is no enantiomeric bioconversion from tamsulosin hydrochloride [R(-) isomer] to the S(+) isomer in humans. Tamsulosin hydrochloride is extensively metabolized by cytochrome P450 enzymes in the liver and less than 10% of the dose is excreted in urine unchanged. However, the pharmacokinetic profile of the metabolites in humans has not been established. Tamsulosin is extensively metabolized, mainly by CYP3A4 and CYP2D6 as well as via some minor participation of other CYP isoenzymes. Inhibition of hepatic drug-metabolizing enzymes may lead to increased exposure to tamsulosin [see Warnings and Precautions (5.2) and Drug Interactions (7.1)]. The metabolites of tamsulosin hydrochloride undergo extensive conjugation to glucuronide or sulfate prior to renal excretion. Incubations with human liver microsomes showed no evidence of clinically significant metabolic interactions between tamsulosin hydrochloride and amitriptyline, albuterol (beta agonist), glyburide (glibenclamide) and finasteride (5-alpha-reductase inhibitor for treatment of BPH). However, results of the in vitro testing of the tamsulosin hydrochloride interaction with diclofenac and warfarin were equivocal. Excretion On administration of the radiolabeled dose of tamsulosin hydrochloride to 4 healthy volunteers, 97% of the administered radioactivity was recovered, with urine (76%) representing the primary route of excretion compared to feces (21%) over 168 hours. Following intravenous or oral administration of an immediate-release formulation, the elimination half-life of tamsulosin hydrochloride in plasma ranged from 5 to 7 hours. Because of absorption rate-controlled pharmacokinetics with tamsulosin hydrochloride capsules, the apparent half-life of tamsulosin hydrochloride is approximately 9 to 13 hours in healthy volunteers and 14 to 15 hours in the target population. Tamsulosin hydrochloride undergoes restrictive clearance in humans, with a relatively low systemic clearance (2.88 L/h). Specific Populations Pediatric use Tamsulosin hydrochloride capsules are not indicated for use in pediatric populations [see Use in Specific Populations (8.4)]. Geriatric (age) use Cross-study comparison of tamsulosin hydrochloride capsules overall exposure (AUC) and half-life indicates that the pharmacokinetic disposition of tamsulosin hydrochloride may be slightly prolonged in geriatric males compared to young, healthy male volunteers. Intrinsic clearance is independent of tamsulosin hydrochloride binding to AAG, but diminishes with age, resulting in a 40% overall higher exposure (AUC) in subjects of age 55 to 75 years compared to subjects of age 20 to 32 years [see Use in Specific Populations (8.5)]. Renal impairment The pharmacokinetics of tamsulosin hydrochloride have been compared in 6 subjects with mild-moderate (30≤ CL cr <70 mL/min/1.73 m 2 ) or moderate-severe (10≤ CL cr <30 mL/min/1.73 m 2 ) renal impairment and 6 normal subjects (CL cr >90 mL/min/1.73 m 2 ). While a change in the overall plasma concentration of tamsulosin hydrochloride was observed as the result of altered binding to AAG, the unbound (active) concentration of tamsulosin hydrochloride, as well as the intrinsic clearance, remained relatively constant. Therefore, patients with renal impairment do not require an adjustment in tamsulosin hydrochloride capsules dosing. However, patients with end-stage renal disease (CL cr <10 mL/min/1.73 m 2 ) have not been studied [see Use in Specific Populations (8.6)]. Hepatic impairment The pharmacokinetics of tamsulosin hydrochloride have been compared in 8 subjects with moderate hepatic impairment (Child-Pugh's classification: Grades A and B) and 8 normal subjects. While a change in the overall plasma concentration of tamsulosin hydrochloride was observed as the result of altered binding to AAG, the unbound (active) concentration of tamsulosin hydrochloride does not change significantly, with only a modest (32%) change in intrinsic clearance of unbound tamsulosin hydrochloride. Therefore, patients with moderate hepatic impairment do not require an adjustment in tamsulosin hydrochloride capsules dosage. Tamsulosin hydrochloride has not been studied in patients with severe hepatic impairment [see Use in Specific Populations (8.7)]. Drug Interactions Cytochrome P450 inhibition Strong and moderate inhibitors of CYP3A4 or CYP2D6 The effects of ketoconazole (a strong inhibitor of CYP3A4) at 400 mg once daily for 5 days on the pharmacokinetics of a single tamsulosin hydrochloride capsule 0.4 mg dose was investigated in 24 healthy volunteers (age range 23 to 47 years). Concomitant treatment with ketoconazole resulted in an increase in the C max and AUC of tamsulosin by a factor of 2.2 and 2.8, respectively [see Warnings and Precautions (5.2) and Clinical Pharmacology (12.3)] . The effects of concomitant administration of a moderate CYP3A4 inhibitor (e.g., erythromycin) on the pharmacokinetics of tamsulosin hydrochloride have not been evaluated [see Warnings and Precautions (5.2) and Drug Interactions (7.1)]. The effects of paroxetine (a strong inhibitor of CYP2D6) at 20 mg once daily for 9 days on the pharmacokinetics of a single tamsulosin hydrochloride capsule 0.4 mg dose was investigated in 24 healthy volunteers (age range 23 to 47 years). Concomitant treatment with paroxetine resulted in an increase in the C max and AUC of tamsulosin by a factor of 1.3 and 1.6, respectively [see Warnings and Precautions (5.2) and Drug Interactions (7.1)] . A similar increase in exposure is expected in CYP2D6 poor metabolizers (PM) as compared to extensive metabolizers (EM). A fraction of the population (about 7% of Caucasians and 2% of African Americans) are CYP2D6 PMs. Since CYP2D6 PMs cannot be readily identified and the potential for significant increase in tamsulosin exposure exists when tamsulosin hydrochloride capsules 0.4 mg are coadministered with strong CYP3A4 inhibitors in CYP2D6 PMs, tamsulosin hydrochloride capsules 0.4 mg should not be used in combination with strong inhibitors of CYP3A4 (e.g., ketoconazole) [see Warnings and Precautions (5.2) and Drug Interactions (7.1)]. The effects of concomitant administration of a moderate CYP2D6 inhibitor (e.g., terbinafine) on the pharmacokinetics of tamsulosin hydrochloride have not been evaluated [see Warnings and Precautions (5.2) and Drug Interactions (7.1)] . The effects of coadministration of both a CYP3A4 and a CYP2D6 inhibitor with tamsulosin hydrochloride capsules have not been evaluated. However, there is a potential for significant increase in tamsulosin exposure when tamsulosin hydrochloride capsules 0.4 mg are coadministered with a combination of both CYP3A4 and CYP2D6 inhibitors [see Warnings and Precautions (5.2) and Drug Interactions (7.1)] . Cimetidine The effects of cimetidine at the highest recommended dose (400 mg every 6 hours for 6 days) on the pharmacokinetics of a single tamsulosin hydrochloride capsule 0.4 mg dose was investigated in 10 healthy volunteers (age range 21 to 38 years). Treatment with cimetidine resulted in a significant decrease (26%) in the clearance of tamsulosin hydrochloride, which resulted in a moderate increase in tamsulosin hydrochloride AUC (44%) [see Warnings and Precautions (5.2) and Drug Interactions (7.1)] . Other alpha adrenergic blocking agents The pharmacokinetic and pharmacodynamic interactions between tamsulosin hydrochloride capsules and other alpha adrenergic blocking agents have not been determined; however, interactions between tamsulosin hydrochloride capsules and other alpha adrenergic blocking agents may be expected [see Warnings and Precautions (5.2) and Drug Interactions (7.2)] . PDE5 inhibitors Caution is advised when alpha adrenergic blocking agents, including tamsulosin hydrochloride, are coadministered with PDE5 inhibitors. Alpha-adrenergic blockers and PDE5 inhibitors are both vasodilators that can lower blood pressure. Concomitant use of these two drug classes can potentially cause symptomatic hypotension [see Warnings and Precautions (5.2) and Drug Interactions (7.3)] . Warfarin A definitive drug-drug interaction study between tamsulosin hydrochloride and warfarin was not conducted. Results from limited in vitro and in vivo studies are inconclusive. Therefore, caution should be exercised with concomitant administration of warfarin and tamsulosin hydrochloride capsules [see Warnings and Precautions (5.2) and Drug Interactions (7.4)]. Nifedipine, atenolol, enalapril In three studies in hypertensive subjects (age range 47 to 79 years) whose blood pressure was controlled with stable doses of nifedipine, atenolol, or enalapril for at least 3 months, tamsulosin hydrochloride capsules 0.4 mg for 7 days followed by tamsulosin hydrochloride capsules 0.8 mg for another 7 days (n=8 per study) resulted in no clinically significant effects on blood pressure and pulse rate compared to placebo (n=4 per study). Therefore, dosage adjustments are not necessary when tamsulosin hydrochloride capsules are administered concomitantly with nifedipine, atenolol, or enalapril [see Drug Interactions (7.5)]. Digoxin and theophylline In two studies in healthy volunteers (n=10 per study; age range 19 to 39 years) receiving tamsulosin hydrochloride capsules 0.4 mg/day for 2 days, followed by tamsulosin hydrochloride capsules 0.8 mg/day for 5 to 8 days, single intravenous doses of digoxin 0.5 mg or theophylline 5 mg/kg resulted in no change in the pharmacokinetics of digoxin or theophylline. Therefore, dosage adjustments are not necessary when a tamsulosin hydrochloride capsule is administered concomitantly with digoxin or theophylline [see Drug Interactions (7.6)]. Furosemide The pharmacokinetic and pharmacodynamic interaction between tamsulosin hydrochloride capsules 0.8 mg/day (steady-state) and furosemide 20 mg intravenously (single dose) was evaluated in 10 healthy volunteers (age range 21 to 40 years). Tamsulosin hydrochloride capsules had no effect on the pharmacodynamics (excretion of electrolytes) of furosemide. While furosemide produced an 11% to 12% reduction in tamsulosin hydrochloride C max and AUC, these changes are expected to be clinically insignificant and do not require adjustment of the tamsulosin hydrochloride capsules dosage [see Drug Interactions (7.7)] . Figure 1