Trospium

INDICATIONS AND USAGE Trospium Chloride Extended-Release Capsules are a muscarinic antagonist indicated for the treatment of overactive bladder (OAB) with symptoms of urge urinary incontinence, urgency, and urinary frequency. Trospium Chloride Extended-Release Capsules are a muscarinic antagonist indicated for the treatment of overactive bladder (OAB) with symptoms of urge urinary incontinence, urgency, and urinary frequency. ( 1 )

DOSAGE AND ADMINISTRATION • Assess liver enzymes and bilirubin prior to initiating treatment with COBENFY and as clinically indicated during treatment. ( 2.1 ) • Assess heart rate at baseline and as clinically indicated during treatment with COBENFY. ( 2.1 ) • Recommended starting dosage of COBENFY is 50 mg/20 mg orally twice daily for at least two days, then increase the dosage to 100 mg/20 mg twice daily for at least five days. ( 2.2 ) • Dosage may be increased to 125 mg/30 mg orally twice daily based on patient tolerability and response. ( 2.2 ) • See the full prescribing information for the recommended titration and maximum recommended dosage. ( 2.2 ) • Take at least 1 hour before a meal or at least 2 hours after a meal. Do not open capsules. ( 2.2 ) • Geriatric patients: Recommended starting dosage of COBENFY is 50 mg/20 mg orally twice daily. Consider a slower titration. The maximum recommended dosage is 100 mg/20 mg twice daily. ( 2.3 ) 2.1 Recommended Testing and Monitoring Prior to Initiation and During Treatment with COBENFY • Assess liver enzymes and bilirubin prior to initiating COBENFY and as clinically indicated during treatment [see Contraindications (4) and Warnings and Precautions (5.2 , 5.3) ] . • Assess heart rate at baseline and as clinically indicated during treatment [see Warnings and Precautions (5.7) ] . 2.2 Recommended Dosage and Administration The recommended dosage of COBENFY is as follows: • The recommended starting dosage is one 50 mg/20 mg capsule (contains 50 mg of xanomeline and 20 mg of trospium chloride) orally twice daily for at least two days. • Increase the dosage to one 100 mg/20 mg capsule (contains 100 mg of xanomeline and 20 mg of trospium chloride) orally twice daily for at least five days. • The dosage may be increased to one 125 mg/30 mg capsule (contains 125 mg of xanomeline and 30 mg of trospium chloride) orally twice daily based on patient tolerability and response [see Clinical Studies (14) ] . • Maximum recommended dosage is 125 mg/30 mg orally twice daily. Administer COBENFY orally at least one hour before a meal or at least two hours after a meal [see Clinical Pharmacology (12.3) ] . Do not open the capsules. 2.3 Dosage Recommendations in Geriatric Patients The recommended starting dosage of COBENFY in geriatric patients is one 50 mg/20 mg capsule orally twice daily. Consider a slower titration for geriatric patients. The maximum recommended dosage in geriatric patients is one 100 mg/20 mg capsule twice daily [see Warnings and Precautions (5.1 , 5.8) and Use in Specific Populations (8.5) ] .

WARNINGS AND PRECAUTIONS • Risk of Urinary Retention: COBENFY can cause urinary retention. Geriatric patients and patients with bladder outlet obstruction and incomplete bladder emptying are at increased risk. Monitor patients for symptoms of acute urinary retention. ( 5.1 ) • Risk of Use in Patients with Hepatic Impairment: COBENFY is contraindicated in patients with moderate to severe hepatic impairment and is not recommended in patients with mild hepatic impairment. ( 5.2 ) • Risk of Use in Patients with Biliary Disease: Assess liver enzymes and bilirubin prior to initiating COBENFY and as clinically indicated. Discontinue COBENFY in the presence of signs or symptoms of substantial liver injury. ( 5.3 ) • Decreased Gastrointestinal Motility: COBENFY may decrease gastrointestinal motility. Use with caution in patients with gastrointestinal obstructive disorders because of the risk of gastric retention. ( 5.4 ) • Risk of Angioedema: Angioedema of the face, lips, tongue and/or larynx has been reported with COBENFY. ( 5.5 ) • Risk of Use in Patients with Narrow-angle Glaucoma: Use COBENFY only if the potential benefits outweigh the risks and with careful monitoring. ( 5.6 ) • Increases in Heart Rate: COBENFY may increase heart rate. Assess heart rate at baseline and as clinically indicated during treatment with COBENFY. ( 5.7 ) • Anticholinergic Adverse Reactions in Patients with Renal Impairment: COBENFY is not recommended for use in patients with moderate and severe renal impairment. Anticholinergic adverse reactions are expected to be greater in these patients. ( 5.8 ) • Central Nervous System Effects: COBENFY may be associated with CNS effects. Advise patients not drive or operate heavy machinery until they know how COBENFY affects them. ( 5.9 ) 5.1 Risk of Urinary Retention COBENFY can cause urinary retention [see Adverse Reactions (6.1 )] . Geriatric patients and patients with clinically significant bladder outlet obstruction and incomplete bladder emptying (e.g., patients with benign prostatic hyperplasia (BPH), diabetic cystopathy) may be at increased risk of urinary retention [see Use in Specific Populations (8.5) ] . COBENFY is contraindicated in patients with pre-existing urinary retention [see Contraindications (4) ] and is not recommended in patients with moderate or severe renal impairment [see Use in Specific Populations (8.6) and Clinical Pharmacology (12.3) ] . In patients taking COBENFY, monitor for symptoms of urinary retention, including urinary hesitancy, weak stream, incomplete bladder emptying, and dysuria. Instruct patients to be aware of the risk and promptly report symptoms of urinary retention to their healthcare provider. Urinary retention is a known risk factor for urinary tract infections. In patients with symptoms of urinary retention, consider reducing the dose of COBENFY, discontinuing COBENFY, or referring patients for urologic evaluation as clinically indicated. 5.2 Risk of Use in Patients with Hepatic Impairment Patients with hepatic impairment have higher systemic exposures of xanomeline, a component of COBENFY, compared to patients with normal hepatic function, which may result in increased incidence of COBENFY-related adverse reactions [see Clinical Pharmacology (12.3) ] . COBENFY is contraindicated in patients with moderate or severe hepatic impairment [see Contraindications (4) ] . COBENFY is not recommended in patients with mild hepatic impairment [see Use in Specific Populations (8.7) and Clinical Pharmacology (12.3) ] . Assess liver enzymes prior to initiating COBENFY and as clinically indicated during treatment. 5.3 Risk of Use in Patients with Biliary Disease In clinical studies with COBENFY, transient increases in liver enzymes with rapid decline occurred, consistent with transient biliary obstruction due to biliary contraction and possible gallstone passage [see Adverse Reactions (6.1) ] . COBENFY is not recommended for patients with active biliary disease such as symptomatic gallstones. Assess liver enzymes and bilirubin prior to initiating COBENFY and as clinically indicated during treatment. The occurrence of symptoms such as dyspepsia, nausea, vomiting, or upper abdominal pain should prompt assessment for gallbladder disorders, biliary disorders, and pancreatitis, as clinically indicated. Discontinue COBENFY in the presence of signs or symptoms of substantial liver injury such as jaundice, pruritus, or alanine aminotransferase levels more than five times the upper limit of normal or five times baseline values. 5.4 Decreased Gastrointestinal Motility COBENFY contains trospium chloride. Trospium chloride, like other antimuscarinic agents, may decrease gastrointestinal motility. Administer COBENFY with caution in patients with gastrointestinal obstructive disorders because of the risk of gastric retention [see Contraindications (4) ] . Use COBENFY with caution in patients with conditions such as ulcerative colitis, intestinal atony, and myasthenia gravis. 5.5 Risk of Angioedema Angioedema of the face, lips, tongue, and/or larynx has been reported with COBENFY and trospium chloride, a component of COBENFY [see Adverse Reactions (6.2) ] . In one case, angioedema occurred after the first dose of trospium chloride. Angioedema associated with upper airway swelling may be life-threatening. If involvement of the tongue, hypopharynx, or larynx occurs, discontinue COBENFY and initiate appropriate therapy and/or measures necessary to ensure a patent airway. COBENFY is contraindicated in patients with a history of hypersensitivity to trospium chloride. 5.6 Risk of Use in Patients with Narrow-angle Glaucoma Pupillary dilation may occur due to the anticholinergic effects of COBENFY. This may trigger an acute angle closure attack in patients with anatomically narrow angles. In patients known to have anatomically narrow angles, COBENFY should only be used if the potential benefits outweigh the risks and with careful monitoring [see Contraindications (4) ] . 5.7 Increases in Heart Rate COBENFY can increase heart rate [see Adverse Reactions (6.1) ] . Assess heart rate at baseline and as clinically indicated during treatment with COBENFY [see Dosage and Administration (2.1) ] . 5.8 Anticholinergic Adverse Reactions in Patients with Renal Impairment Trospium chloride, a component of COBENFY, is substantially excreted by the kidney. COBENFY is not recommended in patients with moderate or severe renal impairment (estimated glomerular filtration rate (eGFR) <60 mL/min). Systemic exposure of trospium chloride is higher in patients with moderate and severe renal impairment [see Use in Specific Populations (8.6) and Clinical Pharmacology (12.3) ] . Therefore, anticholinergic adverse reactions (including dry mouth, constipation, dyspepsia, urinary tract infection, and urinary retention) are expected to be greater in patients with moderate and severe renal impairment. 5.9 Central Nervous System Effects Trospium chloride, a component of COBENFY, is associated with anticholinergic central nervous system (CNS) effects [see Adverse Reactions (6.1) ] . A variety of CNS anticholinergic effects have been reported with trospium chloride, including dizziness, confusion, hallucinations, and somnolence. Monitor patients 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 COBENFY affects them. If a patient experiences anticholinergic CNS effects, consider dose reduction or drug discontinuation.

CONTRAINDICATIONS COBENFY is contraindicated in patients with: • urinary retention [see Warnings and Precautions (5.1) ] . • moderate (Child-Pugh Class B) or severe (Child-Pugh Class C) hepatic impairment [see Warnings and Precautions (5.2) ] . • gastric retention [see Warnings and Precautions (5.4) ] . • history of hypersensitivity to COBENFY or trospium chloride. Angioedema has been reported with COBENFY and trospium chloride [see Warnings and Precautions (5.5) ] . • untreated narrow-angle glaucoma [see Warnings and Precautions (5.6) ] . COBENFY is contraindicated in: • urinary retention ( 4 ) • moderate or severe hepatic impairment ( 4 ) • gastric retention ( 4 ) • history of hypersensitivity to COBENFY or trospium chloride ( 4 ) • untreated narrow-angle glaucoma ( 4 )

DRUG INTERACTIONS • Drugs Eliminated by Active Tubular Secretion: Monitor for increased frequency and/or severity of adverse reactions related to COBENFY and to drugs eliminated by active tubular secretion. ( 7.1 ) • Strong CYP2D6 Inhibitors: Monitor for increased frequency and/or severity of COBENFY-related adverse reactions. ( 7.1 ) • Sensitive Substrates of CYP3A4 or P-glycoprotein: Monitor for increased frequency and/or severity of adverse reactions from these substrates. ( 7.1 ) • Antimuscarinic Drugs: Monitor for increased frequency or severity of anticholinergic adverse reactions. ( 7.2 ) 7.1 Clinically Significant Drug Interactions with COBENFY Table 2 displays clinically significant drug interactions with COBENFY. Table 2: Clinically Significant Drug Interactions with COBENFY Strong Inhibitors of CYP2D6 Clinical Implication: CYP2D6 contributes significantly to the metabolism of xanomeline, a component of COBENFY. Concomitant use of COBENFY with strong CYP2D6 inhibitors may increase plasma concentrations of xanomeline, which may increase the frequency and/or severity of adverse reactions from COBENFY [see Clinical Pharmacology (12.3)] . Prevention or Management: Monitor patients for increased frequency and/or severity of adverse reactions related to COBENFY in patients taking COBENFY with strong inhibitors of CYP2D6. Drugs Eliminated by Active Tubular Secretion Clinical Implication: Concomitant use of COBENFY with drugs that are eliminated by active tubular secretion may increase plasma concentrations of trospium a component of COBENFY, and/or the concomitantly used drug due to competition for this elimination pathway, which may increase the frequency and/or severity of adverse reactions from COBENFY or the drug eliminated by active tubular secretion [see Clinical Pharmacology (12.3)] . Prevention or Management: Monitor patients for increased frequency and/or severity of adverse reactions related to COBENFY and adverse reactions related to drugs eliminated by active tubular secretion in patients concomitantly receiving such drugs. Oral Drugs That Are Sensitive Substrates of CYP3A4 Clinical Implication: Xanomeline, a component of COBENFY, transiently inhibits CYP3A4 locally in the gut but not systemically. Concomitant use of COBENFY with oral drugs that are sensitive substrates of CYP3A4 may result in increased plasma concentrations of the oral drugs that are sensitive substrates of CYP3A4. This may increase the frequency and/or severity of adverse reactions from such substrates [see Clinical Pharmacology (12.3)] . Prevention or Management: Monitor patients for increased frequency and/or severity of adverse reactions related to oral drugs that are sensitive substrates of CYP3A4 in patients taking COBENFY with such substrates. Oral Drugs That Are Substrates of P-glycoprotein Clinical Implication: Xanomeline, a component of COBENFY, transiently inhibits P-glycoprotein locally in the gut but not systemically. Concomitant use of COBENFY with oral drugs that are substrates of P-glycoprotein may result in increased plasma concentrations of the oral drugs that are substrates of P-glycoprotein, which may increase the frequency and/or severity of adverse reactions from such substrates [see Clinical Pharmacology (12.3)] . Prevention or Management: Monitor patients for increased frequency and/or severity of adverse reactions related to oral drugs that are narrow therapeutic index substrates of P-glycoprotein in patients taking COBENFY with such substrates. 7.2 Other Antimuscarinic Drugs Concomitant use of COBENFY with other antimuscarinic drugs that produce anticholinergic adverse reactions (e.g., dry mouth, constipation) may increase the frequency and/or severity of such effects. Monitor patients for increased frequency and/or severity of anticholinergic adverse reactions when COBENFY is used concomitantly with other antimuscarinic drugs. 7.3 Effects on Absorption of Drugs COBENFY may potentially alter the absorption of some concomitantly administered drugs due to anticholinergic effects on gastrointestinal motility. Dosage adjustment of concomitant medications may be necessary based on clinical response and tolerability.

ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling: • Risk of Urinary Retention [see Warnings and Precautions (5.1) ] • Risk of Use in Patients with Hepatic Impairment [see Warnings and Precautions (5.2) ] • Risk of Use in Patients with Biliary Disease [see Warnings and Precautions (5.3) ] • Decreased Gastrointestinal Motility [see Warnings and Precautions (5.4) ] • Risk of Angioedema [see Warnings and Precautions (5.5) ] • Risk of Use in Patients with Narrow-angle Glaucoma [see Warnings and Precautions (5.6) ] • Increases in Heart Rate [see Warnings and Precautions (5.7) ] • Anticholinergic Adverse Reactions in Patients with Renal Impairment [see Warnings and Precautions (5.8) ] • Central Nervous System Effects [see Warnings and Precautions (5.9) ] Most common adverse reactions (incidence ≥ 5% and at least twice placebo) were nausea, dyspepsia, constipation, vomiting, hypertension, abdominal pain, diarrhea, tachycardia, dizziness, and gastrointestinal reflux disease. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Bristol-Myers Squibb at 1-800-721-5072 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. COBENFY was evaluated for safety in a total of 1,594 subjects exposed to one or more doses, including 1,135 adult patients with schizophrenia and 389 healthy subjects. A total of 347 COBENFY-treated patients had at least 6 months of exposure and 150 patients had at least 1 year of exposure (defined as ≥ 50 weeks) from open-label studies. The adverse reaction findings are based on two pooled 5-week, placebo-controlled, flexible-dose studies in 504 adult patients with schizophrenia in which COBENFY or placebo was started at an initial dose of 50 mg/20 mg twice daily for the first 2 days followed by 100 mg/20 mg twice daily for the remainder of Week 1 (Days 3 to 7). On Day 8, dosing was titrated to 125 mg/30 mg twice daily unless the patient could not tolerate it. All patients had the option to return to 100 mg/20 mg twice daily for the remainder of the treatment period [see Clinical Studies (14) ] . In the 5-week placebo-controlled studies, 6% of patients treated with COBENFY and 4% of placebo-treated patients discontinued participation due to adverse reactions. Adverse reactions that led to study discontinuation in ≥1% of patients treated with COBENFY include nausea (2%) and vomiting (1%). The most common adverse reactions (≥5% and at least twice placebo) were nausea, dyspepsia, constipation, vomiting, hypertension, abdominal pain, diarrhea, tachycardia, dizziness, and gastroesophageal reflux disease. Adverse reactions reported with COBENFY at an incidence of at least 2% in patients exposed to COBENFY and greater than the rate of placebo are shown in Table 1. Table 1: Adverse Reactions Reported in ≥2% of COBENFY-Treated Patients and Greater than Rate of Placebo in Two 5-week Schizophrenia Trials a Dyspepsia includes dyspepsia, esophageal discomfort b Hypertension includes hypertension, blood pressure increased, labile hypertension, orthostatic hypertension c Abdominal Pain includes abdominal discomfort, abdominal pain upper, abdominal pain, abdominal pain lower, abdominal tenderness d Tachycardia includes tachycardia, heart rate increased, sinus tachycardia e Cough: includes cough, productive cough f EPS (non-akathisia) includes dyskinesia, drooling, dystonia, extrapyramidal disorder, muscle contraction involuntary, muscle spasms COBENFY (N=251) Placebo (N=253) Nausea 19% 4% Dyspepsia a 18% 5% Constipation 17% 7% Vomiting 15% 1% Hypertension b 11% 2% Abdominal Pain c 8% 4% Diarrhea 6% 2% Tachycardia d 5% 2% Dizziness 5% 2% Gastroesophageal reflux disease 5% <1% Dry mouth 4% 2% Somnolence 3% 2% Vision blurred 3% 0% Salivary hypersecretion 2% 0% Orthostatic hypotension 2% 1% Cough e 2% 1% Extrapyramidal symptoms (EPS), non-akathisia f 2% <1% Increases in Heart Rate In a dedicated 8-week clinical study, 24-hour ambulatory blood pressure monitoring (ABPM) was conducted in 133 patients with schizophrenia. A total of 95 patients had acceptable ABPM recordings at both baseline and Week 8. In that group, there was a mean change in 24-hour heart rate of 9.8 beats per minute (bpm) (95% CI 7.5, 12.2) from baseline to Week 8. In the two placebo-controlled schizophrenia studies, COBENFY was associated with increases in heart rate compared to placebo, with peak elevation occurring on Day 8 of study treatment (13.5 bpm in the COBENFY group and 4.0 bpm in the placebo group), partially attenuating with continued dosing (11.4 bpm in the COBENFY group and 5.5 bpm in the placebo group at Week 5). Liver Enzyme Elevations In the 5-week, placebo-controlled schizophrenia studies, the proportions of patients with ALT or AST elevations of ≥3 times the upper limits of the normal reference range were 2.8% (6/214) for COBENFY-treated patients compared to 0.4% (1/224) of placebo-treated patients. Twenty-five (1.6%) of the total 1,594 subjects exposed to COBENFY had elevated liver enzymes. The majority of liver enzyme elevations occurred within the first month of treatment and resolved with continued COBENFY use, suggestive of liver adaptation; some cases required treatment interruption, and one was associated with an increase in bilirubin. Urinary Retention In the 5-week, placebo-controlled studies, urinary retention (urinary hesitation, dysuria, and urinary retention) was reported in 0.8% of COBENFY-treated patients and 0.4% on placebo. In the long-term, open-label studies, urinary retention was reported in 3.5% of COBENFY-treated patients. Urinary retention was more common in males, geriatric patients, and those with certain risk factors [see Warnings and Precautions (5.1) ] . Urinary retention occurred at all doses but was predominately observed at the maximum COBENFY dose. In the long-term, open-label studies, urinary tract infections were reported in 2.3% of COBENFY-treated patients and were more commonly reported in females than males. Of the total 1,594 subjects exposed to COBENFY (including healthy volunteers and patients with schizophrenia or other conditions), four subjects required a Foley catheter, including one with elevated serum creatinine and one with urinary tract infections. Four subjects with urinary retention required reduction of COBENFY dose, four discontinued COBENFY, and four received medications for the treatment of benign prostatic hyperplasia (BPH). 6.2 Postmarketing Experience The following adverse reactions have been identified during post-approval use of trospium chloride, one of the components of COBENFY. 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. • Cardiovascular – chest pain, hypertensive crisis, palpitations, supraventricular tachycardia, syncope • Gastrointestinal – gastritis • General – rash • Musculoskeletal – rhabdomyolysis • Nervous System – confusion, delirium, dizziness, hallucinations, somnolence, vision abnormal • Skin and subcutaneous tissue disorders – angioedema, anaphylactic reaction, Stevens-Johnson syndrome

CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Trospium chloride is a muscarinic antagonist. Trospium chloride antagonizes the effect of acetylcholine on muscarinic receptors in cholinergically innervated organs including the bladder. Its parasympatholytic action reduces the tonus of smooth muscle in the bladder. Receptor assays showed that trospium chloride has negligible affinity for nicotinic receptors as compared to muscarinic receptors at concentrations obtained from therapeutic doses. 12.2 Pharmacodynamics Placebo-controlled studies employing urodynamic variables were conducted in patients with conditions characterized by involuntary detrusor contractions. The results demonstrate that trospium chloride increases maximum cystometric bladder capacity and volume at first detrusor contraction. Electrophysiology The effect of 20 mg twice daily and up to 100 mg twice daily of trospium chloride on QT interval was evaluated in a single-blind, randomized, placebo and active (moxifloxacin 400 mg once daily) controlled 5 day parallel trial in 170 male and female healthy volunteer subjects aged 18 to 45 years. The QT interval was measured over a 24-hour period at steady state. The 100 mg twice daily dose of trospium chloride was chosen because this achieves the C max expected in severe renal impairment. Trospium chloride was not associated with an increase in individual corrected (QTcI) or Fridericia corrected (QTcF) QT interval at any time during steady state measurement, while moxifloxacin was associated with a 6.4 msec increase in QTcF. In this study, asymptomatic, non-specific T wave inversions were observed more often in subjects receiving trospium chloride than in subjects receiving moxifloxacin or placebo following five days of treatment. This finding was not observed during routine safety monitoring in 2 other placebo-controlled clinical trials in 591 trospium chloride treated overactive bladder patients [ see Clinical Studies (14) ] . The clinical significance of T wave inversion in this study is unknown. Trospium chloride is associated with an increase in heart rate that correlates with increasing plasma concentrations. In the study described above, trospium chloride demonstrated a mean increase in heart rate compared to placebo of 9.1 bpm for the 20 mg dose and of 18 bpm for the 100 mg dose. In the two U.S. placebo-controlled trials in patients with overactive bladder, the mean increase in heart rate compared to placebo in Study 1 was observed to be 3 bpm and in Study 2 was 4 bpm. 12.3 Pharmacokinetics Absorption : After oral administration, less than 10% of the dose is absorbed. Mean absolute bioavailability of a 20 mg dose is 9.6% (range: 4 to 16.1%). Peak plasma concentrations (C max ) occur between 5 to 6 hours post-dose. Mean C max increases greater than dose-proportionally; a 3-fold and 4-fold increase in C max was observed for dose increases from 20 mg to 40 mg and from 20 mg to 60 mg, respectively. AUC exhibits dose linearity for single doses up to 60 mg. Trospium chloride exhibits diurnal variability in exposure with a decrease in C max and AUC of up to 59% and 33%, respectively, for evening relative to morning doses. Effect of Food: Administration with a high (50%) fat-content meal resulted in reduced absorption, with AUC and C max values 70 to 80% lower than those obtained when trospium chloride was administered while fasting. Therefore, it is recommended that trospium chloride should be taken at least one hour prior to meals or on an empty stomach [ see Dosage and Administration (2) ]. A summary of mean (± standard deviation) pharmacokinetic parameters for a single 20 mg dose of trospium chloride tablets is provided in Table 2. Table 2. Mean (± SD) Pharmacokinetic Parameter Estimates for a Single Dose of Trospium Chloride Tablets in Healthy Volunteers C max (ng/mL) AUC 0-∞ (ng/mL•hr) T max (hr) t ½ (hr) 3.5 ± 4.0 36.4 ± 21.8 5.3 ± 1.2 18.3 ± 3.2 The mean plasma concentration-time (+ SD) profile for trospium chloride is shown in Figure 1. Figure 1 - Mean (+ SD) Concentration-Time Profile for a Single 20 mg Oral Dose of Trospium Chloride Tablets in Healthy Volunteers Distribution : Protein binding ranged from 50 to 85% when concentration levels of trospium chloride (0.5 to 50 ng/mL) were incubated with human serum in vitro. The 3 H-trospium chloride ratio of plasma to whole blood was 1.6:1. This ratio indicates that the majority of 3 H-trospium chloride is distributed in plasma. The apparent volume of distribution for a 20 mg oral dose is 395 (± 140) liters. Metabolism : The metabolic pathway of trospium in humans has not been fully defined. Of the 10% of the dose absorbed, metabolites account for approximately 40% of the excreted dose following oral administration. The major metabolic pathway is hypothesized as ester hydrolysis with subsequent conjugation of benzylic acid to form azoniaspironortropanol with glucuronic acid. Cytochrome P450 (CYP) is not expected to contribute significantly to the elimination of trospium. Data taken from in vitro human liver microsomes investigating the inhibitory effect of trospium on seven CYP isoenzyme substrates (CYP1A2,2A6, 2C9, 2C19, 2D6, 2E1, and 3A4) suggest a lack of inhibition at clinically relevant concentrations. Excretion : The plasma half-life for trospium chloride following oral administration is approximately 20 hours. After oral administration of an immediate-release formulation of 14 C-trospium chloride, the majority of the dose (85.2%) was recovered in feces and a smaller amount (5.8% of the dose) was recovered in urine; 60% of the radioactivity excreted in urine was unchanged trospium. The mean renal clearance for trospium (29.07 L/hour) is 4-fold higher than average glomerular filtration rate, indicating that active tubular secretion is a major route of elimination for trospium. There may be competition for elimination with other compounds that are also renally eliminated [ see Drug Interactions (7.2) ]. Drug Interactions Digoxin : Concomitant use of 20 mg trospium chloride immediate release tablets twice daily at steady state and a single dose of 0.5 mg digoxin in a crossover study with 40 male and female subjects did not affect the pharmacokinetics of either drug. Metformin : A drug interaction study was conducted in which SANCTURA XR ®+ 60 [an extended release form of trospium chloride capsules, 60 mg] once daily was co-administered with Glucophage ®++ (metformin hydrochloride) 500 mg twice daily under steady-state conditions in 44 healthy subjects. Co-administration of 500 mg metformin immediate release tablets twice daily reduced the steady-state systemic exposure of trospium by approximately 29% for mean AUC 0-24 and by 34% for mean C max. The effect of decrease in trospium exposure on the efficacy of SANCTURA XR ®+ [an extended release form of trospium chloride capsules, 60 mg] is unknown. The steady-state pharmacokinetics of metformin were comparable when administered with or without 60 mg SANCTURA XR ®+ [an extended release form of trospium chloride capsules, 60 mg] once daily under fasted condition. The effect of metformin at higher doses on trospium PK is unknown. Specific Populations Age: Age did not appear to significantly affect the pharmacokinetics of trospium chloride, however, increased anticholinergic side effects unrelated to drug exposure were observed in patients greater than or equal to 75 years of age [ see Use in Specific Populations (8.5) ]. Pediatric : The pharmacokinetics of trospium chloride were not evaluated in pediatric patients. Race : Pharmacokinetic differences due to race have not been studied. Gender : Studies comparing the pharmacokinetics in different genders had conflicting results. When a single 40 mg trospium chloride tablets dose was administered to 16 elderly subjects, exposure was 45% lower in elderly females compared to elderly males. When 20 mg trospium chloride tablets was dosed twice daily for 4 days to 6 elderly males and 6 elderly