Fesoterodine

INDICATIONS AND USAGE Fesoterodine fumarate extended-release tablets are indicated for the treatment of: Overactive bladder (OAB) in adults with symptoms of urge urinary incontinence, urgency, and frequency. ( 1.1 ) 1.1 Adult Overactive Bladder Fesoterodine fumarate extended-release tablets are indicated for the treatment of overactive bladder (OAB) in adults with symptoms of urge urinary incontinence, urgency, and frequency. Pediatric use information is approved for Pfizer Inc.’s TOVIAZ ® (fesoterodine fumarate) extended-release tablets. However, due to Pfizer Inc.’s marketing exclusivity rights, this drug product is not labeled with that information. 1.1 Adult Overactive Bladder Fesoterodine fumarate extended-release tablets are indicated for the treatment of overactive bladder (OAB) in adults with symptoms of urge urinary incontinence, urgency, and frequency. Pediatric use information is approved for Pfizer Inc.’s TOVIAZ ® (fesoterodine fumarate) extended-release tablets. However, due to Pfizer Inc.’s marketing exclusivity rights, this drug product is not labeled with that information.

DOSAGE AND ADMINISTRATION OAB in Adults: The recommended starting dosage is 4 mg orally once daily. Based upon individual response and tolerability, increase to the maximum dosage of 8 mg once daily. ( 2.1 ) NDO in Pediatric Patients 6 Years and Older: Pediatric Patients Weighing Greater than 25 kg and up to 35 kg: The recommended dosage is 4 mg orally once daily. If needed, dosage may be increased to 8 mg orally once daily. (2.2) Pediatric Patients Weighing Greater than 35 kg: The recommended starting dosage is 4 mg orally once daily. After one week, increase to 8 mg orally once daily. (2.2) Adult or Pediatric Patients with Renal Impairment: Refer to the full prescribing information for recommended dosage. (2.3, 2.4) Dosage Modifications Due to Strong CYP3A4 Inhibitors: Refer to the full prescribing information for recommended dosage. ( 2.5 ) Administration: Swallow whole with liquid. Do not chew, divide, or crush. Take with or without food. ( 2.6 ) 2.1 Recommended Dosage for Adult Patients with OAB The recommended starting dosage of fesoterodine fumarate extended-release tablets in adults is 4 mg orally once daily. Based upon individual response and tolerability, increase to the maximum dosage of fesoterodine fumarate extended-release tablets 8 mg once daily. For administration instructions, see Dosage and Administration ( 2.6 ). 2.2 Recommended Dosage for Pediatric Patients Aged 6 Years and Older with NDO Pediatric Patients Weighing Greater than 25 kg and up to 35 kg The recommended dosage of fesoterodine fumarate extended-release tablets are 4 mg orally once daily. If needed, dosage may be increased to fesoterodine fumarate extended-release tablets 8 mg orally once daily. For administration instructions, s ee Dosage and Administration ( 2.6 ). Pediatric Patients Weighing Greater than 35 kg The recommended starting dosage of fesoterodine fumarate extended-release tablets are 4 mg orally once daily. After one week, increase to fesoterodine fumarate extended-release tablets 8 mg orally once daily. For administration instructions, see Dosage and Administration ( 2.6) . 2.3 Recommended Dosage in Adult Patients with Renal Impairment The recommended dosage of fesoterodine fumarate extended-release tablets in adult patients with renal impairment is described in Table 1 [see Use in Specific Populations ( 8.6 )]. For administration instructions, see Dosage and Administration ( 2.6 ). Table 1 Fesoterodine Fumarate Extended-Release Tablets Recommended Dose in Adult Patients with Renal Impairment (Administered Orally Once Daily) Estimated Creatinine Clearance 1 Recommended Dose CLcr 30 to 89 mL/min 8 mg CLcr 15 to 29 mL/min 4 mg CLcr <15 mL/min 4 mg 1 Calculate CLcr using the Cockcroft-Gault formula 2.4 Recommended Dosage in Pediatric Patients with Renal Impairment Pediatric Patients Weighing Greater than 25 kg and up to 35 kg The recommended dosage of fesoterodine fumarate extended-release tablets in pediatric patients with renal impairment weighing greater than 25 kg and up to 35 kg is described in Table 2 [see Use in Specific Populations (8.6)]. For administration instructions, see Dosage and Administration ( 2.6 ) . Table 2 Fesoterodine Fumarate Extended-Release Tablets Recommended Dose in Pediatric Patients Aged 6 Years and Older Weighing Greater Than 25 kg and up to 35 kg With Renal Impairment (Administered Orally Once Daily) 1 Estimate GFR using a validated GFR estimating equation for the pediatric age range of the approved indication. 2 Dosing was derived assuming similar proportional effects of renal impairment in adults and pediatric patients 6 years and older. Estimated Glomerular Filtration Rate (GFR) 1 Recommended Dose 2 eGFR 30 to 89 mL/min/1.73m 2 4 mg eGFR 15 to 29 mL/min/1.73m 2 Use is Not Recommended eGFR <15 mL/min/1.73m 2 or requiring dialysis Use is Not Recommended Pediatric Patients weighing greater than 35 kg The recommended dosage of fesoterodine fumarate extended-release tablets in pediatric patients with renal impairment weighing greater than 35 kg is described in Table 3 [see Use in Specific Populations ( 8.6 )]. For administration instructions, see Dosage and Administration ( 2.6 ) . Table 3 Fesoterodine Fumarate Extended-Release Tablets Recommended Dose in Pediatric Patients Aged 6 Years and Older Weighing Greater Than 35 kg With Renal Impairment (Administered Orally Once Daily) 1 Estimate GFR using a validated GFR estimating equation for the pediatric age range of the approved indication. 2 The recommended starting dosage of fesoterodine fumarate extended-release tablets are 4 mg orally once daily. After one week, increase to the recommended dosage of fesoterodine fumarate extended-release tablets 8 mg orally once daily. 3 Dosing was derived assuming similar proportional effects of renal impairment in adults and pediatric patients 6 years and older. Estimated GFR 1 Recommended Dose 3 eGFR 30 to 89 mL/min/1.73m 2 8 mg 2 eGFR15 to 29 mL/min/1.73m 2 4 mg eGFR <15 mL/min/1.73m 2 or requiring dialysis Use is Not Recommended 2.5 Fesoterodine Fumarate Extended-Release Tablets Dosage Modifications Due to Strong CYP3A4 Inhibitors Adult Patients with OAB The maximum recommended dosage is fesoterodine fumarate extended-release tablets 4 mg orally once daily in adult patients taking strong CYP3A4 inhibitors [see Drug Interactions ( 7.2 ) and Clinical Pharmacology ( 12.3 )]. For administration instructions, see Dosage and Administration ( 2.6 ). Pediatric Patients with NDO Pediatric Patients Weighing Greater than 25 kg and up to 35 kg The use of fesoterodine fumarate extended-release tablets in pediatric patients weighing greater than 25 kg and up to 35 kg and taking strong CYP3A4 inhibitors is not recommended [see Drug Interactions ( 7.2 ) and Clinical Pharmacology ( 12.3 )] . For administration instructions, see Dosage and Administration ( 2.6 ) . Pediatric Patients Weighing Greater than 35 kg The maximum recommended dosage is fesoterodine fumarate extended-release tablets 4 mg orally once daily in pediatric patients weighing greater than 35 kg and taking strong CYP3A4 inhibitors [see Drug Interactions ( 7.2 ) and Clinical Pharmacology ( 12.3 )] . For administration instructions, see Dosage and Administration ( 2.6 ) . 2.6 Administration Instructions Swallow fesoterodine fumarate extended-release tablets whole with liquid. Do not chew, divide, or crush. Take with or without food [see Clinical Pharmacology ( 12.3 )].

WARNINGS AND PRECAUTIONS Angioedema: Promptly discontinue fesoterodine fumarate extended-release tablets and provide appropriate therapy. ( 5.1 ) Urinary Retention: Fesoterodine fumarate extended-release tablets are not recommended in patients with clinically significant bladder outlet obstruction because of the risk of urinary retention. ( 5.2 ) Decreased Gastrointestinal Motility: Fesoterodine fumarate extended-release tablets are not recommended for use in patients with decreased gastrointestinal motility, such as those with severe constipation. ( 5.3 ) Worsening of Narrow Angle Glaucoma: Use fesoterodine fumarate extended-release tablets with caution in patients being treated for narrow-angle glaucoma. ( 5.4 ) Central Nervous System Effects: Somnolence has been reported with fesoterodine fumarate extended-release tablets. Advise patients not to drive or operate heavy machinery until they know how fesoterodine fumarate extended-release tablets affects them. ( 5.5 ) Worsening of Myasthenia Gravis Symptoms: Use fesoterodine fumarate extended-release tablets with caution in patients with myasthenia gravis. ( 5.6 ) 5.1 Angioedema Angioedema of the face, lips, tongue, and/or larynx has been reported with fesoterodine fumarate extended-release tablets. In some cases, angioedema occurred after the first dose; however, cases have been reported to occur hours after the first dose or after multiple doses. Angioedema associated with upper airway swelling may be life-threatening. Fesoterodine fumarate extended-release tablets are contraindicated in patients with a known or suspected hypersensitivity to fesoterodine fumarate extended-release tablets or any of its ingredients [see Contraindications ( 4 )]. If involvement of the tongue, hypopharynx, or larynx occurs, fesoterodine fumarate extended-release tablets should be promptly discontinued and appropriate therapy and/or measures to ensure a patent airway should be promptly provided. 5.2 Urinary Retention in Adult Patients with Bladder Outlet Obstruction The use of fesoterodine fumarate extended-release tablets, like other antimuscarinic drugs, in patients with clinically significant bladder outlet obstruction, including patients with urinary retention, may result in further urinary retention and kidney injury. The use of fesoterodine fumarate extended-release tablets is not recommended in patients with clinically significant bladder outlet obstruction, and is contraindicated in patients with urinary retention [see Contraindications ( 4 ) and Adverse Reactions ( 6.1 )]. 5.3 Decreased Gastrointestinal Motility Fesoterodine fumarate extended-release tablets are associated with decreased gastric motility. Fesoterodine fumarate extended-release tablets are contraindicated in patients with gastric retention [see Contraindications ( 4 )]. The use of fesoterodine fumarate extended-release tablets are not recommended in patients with decreased gastrointestinal motility, such as those with severe constipation. 5.4 Worsening of Narrow-Angle Glaucoma Fesoterodine fumarate extended-release tablets can worsen controlled narrow-angle glaucoma. Fesoterodine fumarate extended-release tablets are contraindicated in patients with uncontrolled narrow-angle glaucoma [see Contraindications ( 4 )]. Fesoterodine fumarate extended-release tablets should be used with caution in patients being treated for narrow-angle glaucoma. 5.5 Central Nervous System Effects Fesoterodine fumarate extended-release tablets are associated with anticholinergic central nervous system (CNS) adverse reactions [see Adverse Reactions ( 6.1 )]. A variety of CNS anticholinergic effects have been reported, including headache, dizziness, and somnolence. Patients should be monitored for signs of anticholinergic CNS effects, particularly after beginning treatment or increasing the dose. Advise patients not to drive or operate heavy machinery until they know how fesoterodine fumarate affects them. If a patient experiences anticholinergic CNS effects, fesoterodine fumarate extended-release tablets dose reduction or discontinuation should be considered. 5.6 Worsening of Myasthenia Gravis Symptoms Fesoterodine fumarate extended-release tablets should be used with caution in patients with myasthenia gravis due to the risk of worsening of symptoms of the disease.

CONTRAINDICATIONS Fesoterodine fumarate extended-release tablets are contraindicated in patients with any of the following, known or suspected hypersensitivity to fesoterodine fumarate extended-release tablets or any of its ingredients, or to tolterodine tartrate tablets or tolterodine tartrate extended-release capsules [s ee Clinical Pharmacology ( 12.1 ) ]. Reactions have included angioedema [ see Warnings and Precautions ( 5.1 ) ]. urinary retention [ see Warnings and Precautions ( 5.2 ) ] gastric retention [ see Warnings and Precautions ( 5.3 ) ] uncontrolled narrow-angle glaucoma [ see Warnings and Precautions ( 5.4 ) ] • Known or suspected hypersensitivity to fesoterodine fumarate extended-release tablets or any of its ingredients or to tolterodine tartrate tablets or tolterodine tartrate extended-release capsules. ( 4 ) • Urinary retention ( 4 ) • Gastric retention ( 4 ) • Uncontrolled narrow-angle glaucoma. ( 4 )

DRUG INTERACTIONS 7.1 Antimuscarinic Drugs Coadministration of fesoterodine fumarate with other antimuscarinic agents that produce dry mouth, constipation, urinary retention, and other anticholinergic pharmacological effects may increase the frequency and/or severity of such effects. Anticholinergic agents may potentially alter the absorption of some concomitantly administered drugs due to anticholinergic effects on gastrointestinal motility. 7.2 CYP3A4 Inhibitors Doses of fesoterodine fumarate extended-release tablets greater than 4 mg are not recommended in adult patients taking strong CYP3A4 inhibitors, such as ketoconazole, itraconazole, and clarithromycin [see Dosage and Administration (2.5)]. The fesoterodine fumarate extended-release dose in pediatric patients taking strong CYP3A4 inhibitors is recommended to be reduced to 4 mg once daily in patients >35 kg and is not recommended in patients weighing greater than 25 kg and up to 35 kg [see Dosage and Administration ( 2.5 )]. In a study in adults, coadministration of the strong CYP3A4 inhibitor ketoconazole with fesoterodine led to approximately a doubling of the maximum concentration (C max ) and area under the concentration versus time curve (AUC) of 5-hydroxymethyl tolterodine (5-HMT), the active metabolite of fesoterodine. Compared with CYP2D6 extensive metabolizers not taking ketoconazole, further increases in the exposure to 5-HMT were observed in subjects who were CYP2D6 poor metabolizers taking ketoconazole [ see Clinical Pharmacology ( 12.3 ) ]. There is no clinically relevant effect of moderate CYP3A4 inhibitors on the pharmacokinetics of fesoterodine. Following blockade of CYP3A4 by coadministration of the moderate CYP3A4 inhibitor fluconazole 200 mg twice a day for 2 days, the average (90% confidence interval) increase in C max and AUC of the active metabolite of fesoterodine was approximately 19% (11% to 28%) and 27% (18% to 36%) respectively. No dosing adjustments are recommended in the presence of moderate CYP3A4 inhibitors (e.g., erythromycin, fluconazole, diltiazem, verapamil and grapefruit juice). The effect of weak CYP3A4 inhibitors (e.g. cimetidine) was not examined; it is not expected to be in excess of the effect of moderate inhibitors [ see Clinical Pharmacology ( 12.3 ) ]. 7.3 CYP3A4 Inducers No dosing adjustments are recommended in the presence of CYP3A4 inducers, such as rifampin and carbamazepine. Following induction of CYP3A4 by coadministration of rifampin 600 mg once a day, C max and AUC of the active metabolite of fesoterodine decreased by approximately 70% and 75%, respectively, after oral administration of fesoterodine fumarate extended-release tablets 8 mg. The terminal half-life of the active metabolite was not changed. 7.4 CYP2D6 Inhibitors The interaction with CYP2D6 inhibitors was not tested clinically. In poor metabolizers for CYP2D6, representing a maximum CYP2D6 inhibition, C max and AUC of the active metabolite are increased 1.7- and 2-fold, respectively. No dosing adjustments are recommended in the presence of CYP2D6 inhibitors. 7.5 Drugs Metabolized by Cytochrome P450 In vitro data indicate that at therapeutic concentrations, the active metabolite of fesoterodine does not have the potential to inhibit or induce Cytochrome P450 enzyme systems [ see Clinical Pharmacology ( 12.3 ) ]. 7.6 Oral Contraceptives In the presence of fesoterodine, there are no clinically significant changes in the plasma concentrations of combined oral contraceptives containing ethinyl estradiol and levonorgestrel [ see Clinical Pharmacology ( 12.3 ) ]. 7.7 Warfarin A clinical study has shown that fesoterodine extended-release tablets 8 mg once daily has no significant effect on the pharmacokinetics or the anticoagulant activity (PT/INR) of warfarin 25 mg. Standard therapeutic monitoring for warfarin should be continued [see Clinical Pharmacology ( 12.3 )]. 7.8 Drug-Laboratory Test Interactions Interactions between fesoterodine fumarate and laboratory tests have not been studied

ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in labeling: • Angioedema [see Warnings and Precautions (5.1)] • Urinary Retention [see Warnings and Precautions (5.2)] • Decreased Gastointestinal Motility [see Warnings and Precautions (5.3)] • Most frequently reported adverse events with fesoterodine fumarate in adult patients with OAB (≥4%) were: dry mouth (placebo, 7%; fesoterodine fumarate 4 mg, 19%; fesoterodine fumarate 8 mg, 35%) and constipation (placebo, 2%; fesoterodine fumarate 4 mg, 4%; fesoterodine fumarate 8 mg, 6%). ( 6.1 ) • Most frequently reported adverse reactions with fesoterodine fumarate in pediatric patients (≥2%) with NDO were: diarrhea, urinary tract infection (UTI), dry mouth, constipation, abdominal pain, nausea, weight increased, and headache. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Alembic Pharmaceuticals Limited at 1-866-210-9797 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 practice. Adult Overactive Bladder (OAB) The safety of fesoterodine fumarate was evaluated in Phase 2 and 3 controlled trials in a total of 2,859 patients with overactive bladder, of which 2,288 were treated with fesoterodine fumarate. Of this total, 782 received fesoterodine fumarate 4 mg/day, and 785 received fesoterodine fumarate 8 mg/day with treatment periods of 8-or 12-weeks. Approximately 80% of these patients had greater than 10-weeks of exposure to fesoterodine fumarate in these trials. A total of 1,964 patients participated in two 12-week, Phase 3 efficacy and safety studies and subsequent open-label extension studies. In these two studies combined, 554 patients received fesoterodine fumarate 4 mg/day and 566 patients received fesoterodine fumarate 8 mg/day. In Phase 2 and 3 placebo-controlled trials combined, the incidences of serious adverse events in patients receiving placebo, fesoterodine fumarate 4 mg, and fesoterodine fumarate 8 mg were 1.9%, 3.5%, and 2.9%, respectively. All serious adverse events were judged to be not related or unlikely to be related to study medication by the investigator, except for four patients receiving fesoterodine fumarate who reported one serious adverse reaction each: angina, chest pain, gastroenteritis, and QT prolongation on ECG. The most commonly reported adverse event in patients treated with fesoterodine fumarate was dry mouth. The incidence of dry mouth was higher in those taking 8 mg/day (35%) and in those taking 4 mg/day (19%), as compared to placebo (7%). Dry mouth led to discontinuation in 0.4%, 0.4%, and 0.8% of patients receiving placebo, fesoterodine fumarate 4 mg, and fesoterodine fumarate 8 mg, respectively. For those patients who reported dry mouth, most had their first occurrence of the event within the first month of treatment. The second most commonly reported adverse event was constipation. The incidence of constipation was 2% in those taking placebo, 4% in those taking 4 mg/day, and 6% in those taking 8 mg/day. Table 4 lists adverse events, regardless of causality, that were reported in the combined Phase 3, randomized, placebo-controlled trials at an incidence greater than placebo and in 1% or more of patients treated with fesoterodine fumarate 4 mg or 8 mg once daily for up to 12-weeks. Table 4: Adverse Events With an Incidence Exceeding the Placebo Rate and Reported by ≥1% of Patients From Double-Blind, Placebo-Controlled Phase 3 Trials of 12-Weeks Treatment Duration System organ class/Preferred term Placebo N=554 % Fesoterodine fumarate 4 mg/day N=554 % Fesoterodine fumarate 8 mg/day N=566 % Gastrointestinal disorders Dry mouth 7 18.8 34.6 Constipation 2 4.2 6 Dyspepsia 0.5 1.6 2.3 Nausea 1.3 0.7 1.9 Abdominal pain upper 0.5 1.1 0.5 Infections Urinary tract infection 3.1 3.2 4.2 Upper respiratory tract infection 2.2 2.5 1.8 Eye disorders Dry eyes 0 1.4 3.7 Renal and urinary disorders Dysuria 0.7 1.3 1.6 Urinary retention 0.2 1.1 1.4 Respiratory disorders Cough 0.5 1.6 0.9 Dry throat 0.4 0.9 2.3 General disorders Edema peripheral 0.7 0.7 1.2 Musculoskeletal disorders Back pain 0.4 2 0.9 Psychiatric disorders Insomnia 0.5 1.3 0.4 Investigations ALT increased 0.9 0.5 1.2 GGT increased 0.4 0.4 1.2 Skin disorders Rash 0.5 0.7 1.1 ALT = alanine aminotransferase; GGT = gamma glutamyltransferase Patients also received fesoterodine fumarate for up to three years in open-label extension phases of one Phase 2 and two Phase 3 controlled trials. In all open-label trials combined, 857, 701, 529, and 105 patients received fesoterodine fumarate for at least 6 months, 1 year, 2 years, and 3 years, respectively. The adverse events observed during long-term, open-label studies were similar to those observed in the 12-week, placebo-controlled studies, and included dry mouth, constipation, dry eyes, dyspepsia, and abdominal pain. Similar to the controlled studies, most adverse events of dry mouth and constipation were mild to moderate in intensity. Serious adverse events, judged to be at least possibly related to study medication by the investigator and reported more than once during the open-label treatment period of up to 3 years, included urinary retention (3 cases), diverticulitis (3 cases), constipation (2 cases), irritable bowel syndrome (2 cases), and electrocardiogram QT corrected interval prolongation (2 cases). Pediatric Neurogenic Detrusor Overactivity (NDO) The safety of fesoterodine fumarate was evaluated in a total of 131 pediatric patients with NDO. Patients received fesoterodine fumarate 4 mg or fesoterodine fumarate 8 mg orally once daily in two clinical trials (Studies 3 and 4). Study 3 was a Phase 3 study in pediatric patients with NDO from 6 years to 17 years of age and weighing greater than 25 kg. This study consisted of a 12-week efficacy phase, in which 84 patients received fesoterodine fumarate, followed by a 12-week safety extension phase, in which 103 patients received fesoterodine fumarate. Of the 103 patients who received fesoterodine fumarate in the safety extension phase, 67 continued fesoterodine fumarate from the efficacy phase and 36 switched from an active comparator in the efficacy phase to fesoterodine fumarate in the safety extension phase. Study 4 (N=11) was an 8-week, Phase 2 pharmacokinetic (PK) and safety study in pediatric patients with NDO from 8 years to 17 years of age. The most commonly reported adverse reactions in pediatric patients with NDO who received fesoterodine fumarate 4 mg or 8 mg in Study 3 (≥2%) were diarrhea, UTI, dry mouth, constipation, abdominal pain, nausea, weight increased and headache. Table 5 lists the adverse reactions reported at an incidence greater than or equal to 2% in either treatment group in the Study 3 efficacy phase. Table 5: Adverse Reactions Reported in ≥2% of Patients With NDO Aged 6 Years to 17 Years in the 12-Week Efficacy Phase of Study 3 Preferred term Fesoterodine Fumarate 4 mg (N=42) % Fesoterodine Fumarate 8 mg (N=42) % Diarrhea 11.9 7.1 Urinary tract infection 9.5 2.4 Dry mouth 7.1 9.5 Constipation 7.1 7.1 Abdominal pain † 7.1 4.8 Nausea 4.8 2.4 Weight increased 4.8 0 Headache 4.8 7.1 † Includes abdominal pain and abdominal pain upper Ophthalmological Adverse Reactions Ophthalmological adverse reactions, including myopia, accommodation disorder and blurred vision, were reported in 8 of 131 (6.1%) pediatric patients with NDO who received fesoterodine fumarate 4 mg or fesoterodine fumarate 8 mg in Study 3 (both efficacy and safety extension phases) and Study 4. The ophthalmological adverse reactions did not result in discontinuation of fesoterodine fumarate in any patient. Increases in Heart Rate Increases in heart rate were reported in pediatric patients with NDO who

CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Fesoterodine is a competitive muscarinic receptor antagonist. After oral administration, fesoterodine is rapidly and extensively hydrolyzed by nonspecific esterases to its active metabolite, 5-hydroxymethyl tolterodine, which is responsible for the antimuscarinic activity of fesoterodine. Muscarinic receptors play a role in contractions of urinary bladder smooth muscle. Inhibition of these receptors in the bladder is presumed to be the mechanism by which fesoterodine produces its effects. 12.2 Pharmacodynamics In a urodynamic study involving patients with involuntary detrusor contractions, the effects after the administration of fesoterodine on the volume at first detrusor contraction and bladder capacity were assessed. Administration of fesoterodine increased the volume at first detrusor contraction and bladder capacity in a dose-dependent manner. These findings are consistent with an antimuscarinic effect on the bladder. Cardiac Electrophysiology The effect of fesoterodine 4 mg and 28 mg on the QT interval was evaluated in a double-blind, randomized, placebo- and positive-controlled (moxifloxacin 400 mg once a day) parallel trial with once-daily treatment over a period of 3 days in 261 male and female subjects aged 44 to 65 years. Electrocardiographic parameters were measured over a 24-hour period at pre-dose, after the first administration, and after the third administration of study medication. Fesoterodine 28 mg was chosen because this dose, when administered to CYP2D6 extensive metabolizers, results in an exposure to the active metabolite that is similar to the exposure in a CYP2D6 poor metabolizer receiving fesoterodine 8 mg together with CYP3A4 blockade. Corrected QT intervals (QTc) were calculated using Fridericia’s correction and a linear individual correction method. Analyses of 24-hour average QTc, time-matched baseline-corrected QTc, and time-matched placebo-subtracted QTc intervals indicate that fesoterodine at doses of 4 and 28 mg/day did not prolong the QT interval. The sensitivity of the study was confirmed by positive QTc prolongation by moxifloxacin. In this study, conducted in subjects aged 44 to 65 years, fesoterodine fumarate was associated with an increase in heart rate that correlates with increasing dose. When compared to placebo, the mean increase in heart rate associated with fesoterodine 4 mg/day and fesoterodine 28 mg/day was 3 beats/minute and 11 beats/minute, respectively. In the two, phase 3, placebo-controlled studies in adult patients with overactive bladder, the mean increases in heart rate compared to placebo were 3 to 4 beats/minute in the fesoterodine 4 mg/day group and 3 to 5 beats/minute in the fesoterodine 8 mg/day group. 12.3 Pharmacokinetics Absorption After oral administration, fesoterodine is well absorbed. Due to rapid and extensive hydrolysis by nonspecific esterases to its active metabolite 5-hydroxymethyl tolterodine, fesoterodine cannot be detected in plasma. Bioavailability of the active metabolite is 52%. After single or multiple-dose oral administration of fesoterodine in doses from 4 mg to 28 mg, plasma concentrations of the active metabolite are proportional to the dose. Maximum plasma levels are reached after approximately 5 hours. No accumulation occurs after multiple-dose administration. A Summary of pharmacokinetic parameters for the active metabolite after a single dose of fesoterodine fumarate 4 mg and 8 mg in extensive and poor metabolizers of CYP2D6 is provided in Table 8. Table 8: Summary of Geometric Mean [CV] Pharmacokinetic Parameters for the Active Metabolite After a Single Dose of fesoterodine fumarate 4 mg and 8 mg in Extensive and Poor CYP2D6 Metabolizers Fesoterodine fumarate 4 mg Fesoterodine fumarate 8 mg Parameter EM (N=16) PM (N=8) EM (N=16) PM (N=8) C max (ng/mL) 1.89 [43%] 3.45 [54%] 3.98 [28%] 6.90 [39%] AUC 0-tz (ng*h/mL) 21.2 [38%] 40.5 [31%] 45.3 [32%] 88.7 [36%] t max (h) a 5 [2 to 6] 5 [5 to 6] 5 [3 to 6] 5 [5 to 6] t 1/2 (h) 7.31 [27%] 7.31 [30%] 8.59 [41%] 7.66 [21%] EM = extensive CYP2D6 metabolizer, PM = poor CYP2D6 metabolizer, CV = coefficient of variation; C max = maximum plasma concentration, AUC 0-tz = area under the concentration time curve from zero up to the last measurable plasma concentration, t max = time to reach C max , t 1/2 = terminal half-life a Data presented as median (range) Effect of Food There is no clinically relevant effect of food on the pharmacokinetics of fesoterodine. In a study of the effects of food on the pharmacokinetics of fesoterodine in 16 healthy male volunteers, concomitant food intake increased the active metabolite of fesoterodine AUC by approximately 19% and C max by 18% [see Dosage and Administration (2.1) ] . Distribution Plasma protein binding of the active metabolite is low (approximately 50%) and is primarily bound to albumin and alpha-1-acid glycoprotein. The mean steady-state volume of distribution following intravenous infusion of the active metabolite is 169 L. Metabolism After oral administration, fesoterodine is rapidly and extensively hydrolyzed to its active metabolite. The active metabolite is further metabolized in the liver to its carboxy, carboxy-N-desisopropyl, and N-desisopropyl metabolites via two major pathways involving CYP2D6 and CYP3A4. None of these metabolites contribute significantly to the antimuscarinic activity of fesoterodine. Variability in CYP2D6 Metabolism A subset of individuals (approximately 7% of Caucasians and approximately 2% of African Americans) are poor metabolizers for CYP2D6. C max and AUC of the active metabolite are increased 1.7- and 2-fold, respectively, in CYP2D6 poor metabolizers, as compared to extensive metabolizers. Excretion Hepatic metabolism and renal excretion contribute significantly to the elimination of the active metabolite. After oral administration of fesoterodine, approximately 70% of the administered dose was recovered in urine as the active metabolite (16%), carboxy metabolite (34%), carboxy-N-desisopropyl metabolite (18%), or N-desisopropyl metabolite (1%), and a smaller amount (7%) was recovered in feces. The terminal half-life of the active metabolite is approximately 4 hours following an intravenous administration. The apparent terminal half-life following oral administration is approximately 7 hours. Pharmacokinetics in Specific Populations Geriatric Patients Following a single 8 mg oral dose of fesoterodine, the mean (±SD) AUC and C max for the active metabolite 5-hydroxymethyl tolterodine in 12 elderly men (mean age 67 years) were 51.8 ± 26.1 h*ng/mL and 3.8 ± 1.7 ng/mL, respectively. In the same study, the mean (±SD) AUC and C max in 12 young men (mean age 30 years) were 52.0 ± 31.5 h*ng/mL and 4.1 ± 2.1 ng/mL, respectively. The pharmacokinetics of fesoterodine were not significantly influenced by age [see Use in Specific Populations (8.5) ] . Gender Following a single 8 mg oral dose of fesoterodine, the mean (±SD) AUC and C max for the active metabolite 5-hydroxymethyl tolterodine in 12 elderly men (mean age 67 years) were 51.8 ± 26.1 h*ng/mL and 3.8 ± 1.7 ng/mL, respectively. In the same study, the mean (±SD) AUC and C max in 12 elderly women (mean age 68 years) were 56.0 ± 28.8 h*ng/mL and 4.6 ± 2.3 ng/mL, respectively. The pharmacokinetics of fesoterodine were not significantly influenced by gender. Race The effects of Caucasian or Black race on the pharmacokinetics of fesoterodine were examined in a study of 12 Caucasian and 12 Black African young male volunteers. Each subject received a single oral dose of 8 mg fesoterodine. The mean (±SD) AUC and C max for the active metabolite 5-hydroxymethyl tolterodine in Caucasian males were 73.0 ± 27.8 h*ng/mL and 6.1 ± 2.7 ng/mL, respectively. The mean (±SD) AUC and C max in Black males were 65.8 ± 23.2 h*ng/mL and 5.5 ± 1.9 ng/mL, respectively. The pharmacokinetics of fesoterodine were not significantly influenced by race. Renal Impairment In patients with