Tolterodine

1. INDICATIONS AND USAGE Tolterodine tartrate extended-release capsules, USP are indicated for the treatment of overactive bladder with symptoms of urge urinary incontinence, urgency, and frequency [see CLINICAL STUDIES (14) ] . Tolterodine tartrate extended-release capsules, USP are an antimuscarinic indicated for the treatment of overactive bladder with symptoms of urge urinary incontinence, urgency, and frequency. (1)

DOSAGE AND ADMINISTRATION 4 mg capsules taken orally once daily with water and swallowed whole. ( 2.1 ) 2 mg capsules taken orally once daily with water and swallowed whole in the presence of: mild to moderate hepatic impairment (Child-Pugh class A or B) ( 2.2 ) severe renal impairment [Creatinine Clearance (CCr) 10 to 30 mL/min] ( 2.2 ) drugs that are potent CYP3A4 inhibitors. ( 2.2 ) Tolterodine tartrate extended-release capsules are not recommended for use in patients with CCr <10 mL/min. ( 2.2 ) Tolterodine tartrate extended-release capsules are not recommended for use in patients with severe hepatic impairment (Child-Pugh Class C). ( 2.2 ) 2.1 Dosing Information The recommended dose of tolterodine tartrate extended-release capsules is 4 mg once daily with water and swallowed whole. The dose may be lowered to 2 mg daily based on individual response and tolerability; however, limited efficacy data are available for tolterodine tartrate extended-release capsules, 2 mg [ see CLINICAL STUDIES ( 14 ) ]. 2.2 Dosage Adjustment in Specific Populations For patients with mild to moderate hepatic impairment (Child-Pugh Class A or B) or severe renal impairment (CCr 10 to 30 mL/min), the recommended dose of tolterodine tartrate extended-release capsules is 2 mg once daily. Tolterodine tartrate extended-release capsules are not recommended for use in patients with severe hepatic impairment (Child-Pugh Class C). Patients with CCr<10 mL/min have not been studied and use of tolterodine tartrate extended-release capsules in this population is not recommended [ see WARNINGS AND PRECAUTIONS ( 5.6 ) and USE IN SPECIFIC POPULATIONS ( 8.6 , 8.7 ) ]. 2.3 Dosage Adjustment in Presence of Concomitant Drugs For patients who are taking drugs that are potent inhibitors of CYP3A4 [e.g., ketoconazole, clarithromycin, ritonavir], the recommended dose of tolterodine tartrate extended-release capsules is 2 mg once daily [ see DRUG INTERACTIONS ( 7.2 ) ].

WARNINGS AND PRECAUTIONS Anaphylaxis and angioedema requiring hospitalization and emergency medical treatment have occurred with the first or subsequent doses of tolterodine tartrate extended-release capsules. ( 5.1 ) Urinary Retention: use caution in patients with clinically significant bladder outflow obstruction because of the risk of urinary retention. ( 5.2 ) Gastrointestinal Disorders: use caution in patients with gastrointestinal obstructive disorders or decreased gastrointestinal motility because of the risk of gastric retention. ( 5.3 ) Controlled Narrow-Angle Glaucoma: use caution in patients being treated for narrow-angle glaucoma. ( 5.4 ) Central Nervous System Effects: Somnolence has been reported with tolterodine tartrate extended-release capsules. Advise patients not to drive or operate heavy machinery until they know how tolterodine tartrate extended-release capsules affect them ( 5.5 ) Myasthenia Gravis: use caution in patients with myasthenia gravis. ( 5.8 ) QT Prolongation: consider observations from the thorough QT study in clinical decisions to prescribe tolterodine tartrate extended-release capsules to patients with a known history of QT prolongation or to patients who are taking Class IA (e.g., quinidine, procainamide) or Class III (e.g., amiodarone, sotalol) antiarrhythmic medications. ( 5.9 ) 5.1 Angioedema Anaphylaxis and angioedema requiring hospitalization and emergency medical treatment have occurred with the first or subsequent doses of tolterodine tartrate extended-release capsules. In the event of difficulty in breathing, upper airway obstruction, or fall in blood pressure, tolterodine tartrate extended-release capsules should be discontinued and appropriate therapy promptly provided. 5.2 Urinary Retention Administer tolterodine tartrate extended-release capsules with caution to patients with clinically significant bladder outflow obstruction because of the risk of urinary retention [ see CONTRAINDICATIONS ( 4 ) ]. 5.3 Gastrointestinal Disorders Administer tolterodine tartrate extended-release capsules with caution in patients with gastrointestinal obstructive disorders because of the risk of gastric retention. Tolterodine tartrate extended-release capsules, like other antimuscarinic drugs, may decrease gastrointestinal motility and should be used with caution in patients with conditions associated with decreased gastrointestinal motility (e.g., intestinal atony) [see CONTRAINDICATIONS ( 4 ) ]. 5.4 Controlled Narrow-Angle Glaucoma Administer tolterodine tartrate extended-release capsules with caution in patients being treated for narrow-angle glaucoma [see CONTRAINDICATIONS ( 4 ) ]. 5.5 Central Nervous System Effects Tolterodine tartrate extended-release capsules are associated with anticholinergic central nervous system (CNS) effects [ see ADVERSE REACTIONS ( 6.2 ) ] including dizziness and somnolence [ see ADVERSE REACTIONS ( 6.1 ) ]. 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 the drug’s effects have been determined. If a patient experiences anticholinergic CNS effects, dose reduction or drug discontinuation should be considered. 5.6 Hepatic Impairment The clearance of orally administered tolterodine immediate release was substantially lower in cirrhotic patients than in the healthy volunteers. For patients with mild to moderate hepatic impairment (Child-Pugh Class A or B), the recommended dose for tolterodine tartrate extended-release capsules is 2 mg once daily. Tolterodine tartrate extended-release capsules are not recommended for use in patients with severe hepatic impairment (Child-Pugh Class C) [ see DOSAGE AND ADMINISTRATION ( 2.2 ) and USE IN SPECIFIC POPULATIONS ( 8.6 ) ]. 5.7 Renal Impairment Renal impairment can significantly alter the disposition of tolterodine and its metabolites. The dose of tolterodine tartrate extended-release capsules should be reduced to 2 mg once daily in patients with severe renal impairment (CCr: 10 to 30 mL/min). Patients with CCr<10 mL/min have not been studied and use of tolterodine tartrate extended-release capsules in this population is not recommended [see DOSAGE AND ADMINISTRATION ( 2.2 ) and USE IN SPECIFIC POPULATIONS ( 8.7 ) ]. 5.8 Myasthenia Gravis Administer tolterodine tartrate extended-release capsules with caution in patients with myasthenia gravis, a disease characterized by decreased cholinergic activity at the neuromuscular junction . 5.9 Use in Patients with Congenital or Acquired QT Prolongation In a study of the effect of tolterodine immediate release tablets on the QT interval [ see CLINICAL PHARMACOLOGY ( 12.2 ) ], the effect on the QT interval appeared greater for 8 mg/day (two times the therapeutic dose) compared to 4 mg/day and was more pronounced in CYP2D6 poor metabolizers (PM) than extensive metabolizers (EMs). The effect of tolterodine 8 mg/day was not as large as that observed after four days of therapeutic dosing with the active control moxifloxacin. However, the confidence intervals overlapped. These observations should be considered in clinical decisions to prescribe tolterodine tartrate extended-release capsules to patients with a known history of QT prolongation or to patients who are taking Class IA (e.g., quinidine, procainamide) or Class III (e.g., amiodarone, sotalol) antiarrhythmic medications. There has been no association of Torsade de Pointes in the international post-marketing experience with tolterodine tartrate tablets or tolterodine tartrate extended-release capsules.

CONTRAINDICATIONS Tolterodine tartrate extended-release capsules are contraindicated in patients with urinary retention, gastric retention, or uncontrolled narrow-angle glaucoma. Tolterodine tartrate extended-release capsules are also contraindicated in patients with known hypersensitivity to the drug or its ingredients, or to fesoterodine fumarate extended-release tablets which, like tolterodine tartrate extended-release capsules, are metabolized to 5-hydroxymethyl tolterodine [ see WARNINGS AND PRECAUTIONS ( 5.2 ), ( 5.3 ), ( 5.4 ) ]. Tolterodine tartrate extended-release capsules are contraindicated in patients with urinary retention, gastric retention, or uncontrolled narrow-angle glaucoma. Tolterodine tartrate extended-release capsules are also contraindicated in patients with known hypersensitivity to the drug or its ingredients, or to fesoterodine fumarate extended-release tablets which, like tolterodine tartrate extended-release capsules, are metabolized to 5-hydroxymethyl tolterodine. ( 4 )

DRUG INTERACTIONS • Potent CYP3A4 Inhibitors: Coadministration may increase systemic exposure to tolterodine tartrate extended-release capsules. Reduce tolterodine tartrate extended-release capsules dose to 2 mg once daily. ( 7.2 ) • Other Anticholinergics (antimuscarinics): Concomitant use with other anticholinergic agents may increase the frequency and/or severity of dry mouth, constipation, blurred vision, and other anticholinergic pharmacological effects. ( 7.6 ) 7.1 Potent CYP2D6 Inhibitors Fluoxetine, a potent inhibitor of CYP2D6 activity, significantly inhibited the metabolism of tolterodine immediate release in CYP2D6 extensive metabolizers, resulting in a 4.8-fold increase in tolterodine AUC. There was a 52% decrease in C max and a 20% decrease in AUC of 5-hydroxymethyl tolterodine (5-HMT), the pharmacologically active metabolite of tolterodine [see Clinical Pharmacology (12.1) ] . The sums of unbound serum concentrations of tolterodine and 5-HMT are only 25% higher during the interaction. No dose adjustment is required when tolterodine and fluoxetine are co-administered [see Clinical Pharmacology (12.3) ] . 7.2 Potent CYP3A4 Inhibitors Ketoconazole (200 mg daily), a potent CYP3A4 inhibitor, increased the mean C max and AUC of tolterodine by 2- and 2.5-fold, respectively, in CYP2D6 poor metabolizers. For patients receiving ketoconazole or other potent CYP3A4 inhibitors such as itraconazole, clarithromycin, or ritonavir, the recommended dose of tolterodine tartrate extended-release capsules is 2 mg once daily [see Dosage and Administration (2.2) and Clinical Pharmacology (12.3) ] . 7.3 Other Interactions No clinically relevant interactions have been observed when tolterodine was co-administered with warfarin, with a combined oral contraceptive drug containing ethinyl estradiol and levonorgestrel, or with diuretics [see Clinical Pharmacology (12.3) ] . 7.4 Other Drugs Metabolized by Cytochrome P450 Isoenzymes In vivo drug-interaction data show that tolterodine immediate release does not result in clinically relevant inhibition of CYP1A2, 2D6, 2C9, 2C19, or 3A4 as evidenced by lack of influence on the marker drugs caffeine, debrisoquine, S-warfarin, and omeprazole [see Clinical Pharmacology (12.3) ] . 7.5 Drug-Laboratory-Test Interactions Interactions between tolterodine and laboratory tests have not been studied. 7.6 Other Anticholinergics The concomitant use of tolterodine tartrate extended-release capsules with other anticholinergic (antimuscarinic) agents may increase the frequency and/or severity of dry mouth, constipation, blurred vision, somnolence, and other anticholinergic pharmacological effects. Drug Interactions Potent CYP2D6 Inhibitors Fluoxetine is a selective serotonin reuptake inhibitor and a potent inhibitor of CYP2D6 activity. In a study to assess the effect of fluoxetine on the pharmacokinetics of tolterodine immediate release and its metabolites, it was observed that fluoxetine significantly inhibited the metabolism of tolterodine immediate release in extensive metabolizers, resulting in a 4.8-fold increase in tolterodine AUC. There was a 52% decrease in C max and a 20% decrease in AUC of 5-hydroxymethyl tolterodine (5-HMT, the pharmacologically active metabolite of tolterodine). Fluoxetine thus alters the pharmacokinetics in patients who would otherwise be CYP2D6 extensive metabolizers of tolterodine immediate release to resemble the pharmacokinetic profile in poor metabolizers. The sums of unbound serum concentrations of tolterodine immediate release and 5-HMT are only 25% higher during the interaction. No dose adjustment is required when tolterodine and fluoxetine are co-administered. Potent CYP3A4 Inhibitors The effect of a 200 mg daily dose of ketoconazole on the pharmacokinetics of tolterodine immediate release was studied in 8 healthy volunteers, all of whom were CYP2D6 poor metabolizers. In the presence of ketoconazole, the mean C max and AUC of tolterodine increased by 2- and 2.5-fold, respectively. Based on these findings, other potent CYP3A4 inhibitors may also lead to increases of tolterodine plasma concentrations. For patients receiving ketoconazole or other potent CYP3A4 inhibitors such as itraconazole, miconazole, clarithromycin, ritonavir, the recommended dose of tolterodine tartrate extended-release capsules is 2 mg daily [see Dosage and Administration (2.3) ] . Warfarin In healthy volunteers, coadministration of tolterodine immediate release 4 mg (2 mg bid) for 7 days and a single dose of warfarin 25 mg on day 4 had no effect on prothrombin time, Factor VII suppression, or on the pharmacokinetics of warfarin. Oral Contraceptives Tolterodine immediate release 4 mg (2 mg bid) had no effect on the pharmacokinetics of an oral contraceptive (ethinyl estradiol 30 µg/levonorgestrel 150 µg) as evidenced by the monitoring of ethinyl estradiol and levonorgestrel over a 2-month period in healthy female volunteers. Diuretics Coadministration of tolterodine immediate release up to 8 mg (4 mg bid) for up to 12 weeks with diuretic agents, such as indapamide, hydrochlorothiazide, triamterene, bendroflumethiazide, chlorothiazide, methylchlorothiazide, or furosemide, did not cause any adverse electrocardiographic (ECG) effects. Effect of Tolterodine on Other Drugs Metabolized by Cytochrome P450 Enzymes Tolterodine immediate release does not cause clinically significant interactions with other drugs metabolized by the major drug-metabolizing CYP enzymes. In vivo drug-interaction data show that tolterodine immediate release does not result in clinically relevant inhibition of CYP1A2, 2D6, 2C9, 2C19, or 3A4 as evidenced by lack of influence on the marker drugs caffeine, debrisoquine, S-warfarin, and omeprazole. In vitro data show that tolterodine immediate release is a competitive inhibitor of CYP2D6 at high concentrations (Ki 1.05 µM), while tolterodine immediate release as well as the 5-HMT are devoid of any significant inhibitory potential regarding the other isoenzymes.

ADVERSE REACTIONS The Phase 2 and 3 clinical trial program for tolterodine tartrate tablets included 3071 patients who were treated with tolterodine tartrate tablets (N=2133) or placebo (N=938). The patients were treated with 1, 2, 4, or 8 mg/day for up to 12 months. No differences in the safety profile of tolterodine were identified based on age, gender, race, or metabolism. The data described below reflect exposure to tolterodine tartrate tablets 2 mg bid in 986 patients and to placebo in 683 patients exposed for 12 weeks in five Phase 3, controlled clinical studies. 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. The adverse reaction information from clinical trials does, however, provide a basis for identifying the adverse events that appear to be related to drug use and approximating rates. Sixty-six percent of patients receiving tolterodine tartrate tablets 2 mg bid reported adverse events versus 56% of placebo patients. The most common adverse events reported by patients receiving tolterodine tartrate tablets were dry mouth, headache, constipation, vertigo/dizziness, and abdominal pain. Dry mouth, constipation, abnormal vision (accommodation abnormalities), urinary retention, and xerophthalmia are expected side effects of antimuscarinic agents. Dry mouth was the most frequently reported adverse event for patients treated with tolterodine tartrate tablets 2 mg bid in the Phase 3 clinical studies, occurring in 34.8% of patients treated with tolterodine tartrate tablets and 9.8% of placebo-treated patients. One percent of patients treated with tolterodine tartrate tablets discontinued treatment due to dry mouth. The frequency of discontinuation due to adverse events was highest during the first 4 weeks of treatment. Seven percent of patients treated with tolterodine tartrate tablets 2 mg bid discontinued treatment due to adverse events versus 6% of placebo patients. The most common adverse events leading to discontinuation of tolterodine tartrate tablets were dizziness and headache. Three percent of patients treated with tolterodine tartrate tablets 2 mg bid reported a serious adverse event versus 4% of placebo patients. Significant ECG changes in QT and QTc have not been demonstrated in clinical-study patients treated with tolterodine tartrate tablets 2 mg bid. Table 5 lists the adverse events reported in 1% or more of the patients treated with tolterodine tartrate tablets 2 mg bid in the 12-week studies. The adverse events are reported regardless of causality. Table 5. Incidence in nearest integer. (%) of Adverse Events Exceeding Placebo Rate and Reported in >1% of Patients Treated with Tolterodine TartrateTablets (2 mg bid) in 12-week, Phase 3 Clinical Studies Body System Adverse Event % Tolterodine Tartrate Tablets N=986 % Placebo N=683 Autonomic Nervous accommodation abnormal 2 1 dry mouth 35 10 General chest pain 2 1 fatigue 4 3 headache 7 5 influenza-like symptoms 3 2 Central/Peripheral Nervous vertigo/dizziness 5 3 Gastrointestinal abdominal pain 5 3 constipation 7 4 diarrhea 4 3 dyspepsia 4 1 Urinary dysuria 2 1 Skin/Appendages dry skin 1 0 Musculoskeletal arthralgia 2 1 Vision xerophthalmia 3 2 Psychiatric somnolence 3 2 Metabolic/Nutritional weight gain 1 0 Resistance Mechanism infection 1 0 Post-marketing Surveillance The following events have been reported in association with tolterodine use in worldwide post-marketing experience: General: anaphylaxis and angioedema; Cardiovascular: tachycardia, palpitations, peripheral edema; Central/Peripheral Nervous: confusion, disorientation, memory impairment, hallucinations. Reports of aggravation of symptoms of dementia (e.g., confusion, disorientation, delusion) have been reported after tolterodine therapy was initiated in patients taking cholinesterase inhibitors for the treatment of dementia. Because these spontaneously reported events are from the worldwide post-marketing experience, the frequency of events and the role of tolterodine in their causation cannot be reliably determined.

CLINICAL PHARMACOLOGY Tolterodine is a competitive muscarinic receptor antagonist. Both urinary bladder contraction and salivation are mediated via cholinergic muscarinic receptors. After oral administration, tolterodine is metabolized in the liver, resulting in the formation of the 5-hydroxymethyl derivative, a major pharmacologically active metabolite. The 5-hydroxymethyl metabolite, which exhibits an antimuscarinic activity similar to that of tolterodine, contributes significantly to the therapeutic effect. Both tolterodine and the 5-hydroxymethyl metabolite exhibit a high specificity for muscarinic receptors, since both show negligible activity or affinity for other neurotransmitter receptors and other potential cellular targets, such as calcium channels. Tolterodine has a pronounced effect on bladder function. Effects on urodynamic parameters before and 1 and 5 hours after a single 6.4 mg dose of tolterodine immediate release were determined in healthy volunteers. The main effects of tolterodine at 1 and 5 hours were an increase in residual urine, reflecting an incomplete emptying of the bladder, and a decrease in detrusor pressure. These findings are consistent with an antimuscarinic action on the lower urinary tract. Pharmacokinetics Absorption: In a study with 14 C-tolterodine solution in healthy volunteers who received a 5 mg oral dose, at least 77% of the radiolabeled dose was absorbed. Tolterodine immediate release is rapidly absorbed, and maximum serum concentrations (C max ) typically occur within 1 to 2 hours after dose administration. C max and area under the concentration-time curve (AUC) determined after dosage of tolterodine immediate release are dose-proportional over the range of 1 to 4 mg. Effect of Food: Food intake increases the bioavailability of tolterodine (average increase 53%), but does not affect the levels of the 5-hydroxymethyl metabolite in extensive metabolizers. This change is not expected to be a safety concern and adjustment of dose is not needed. Distribution: Tolterodine is highly bound to plasma proteins, primarily α1-acid glycoprotein. Unbound concentrations of tolterodine average 3.7% ± 0.13% over the concentration range achieved in clinical studies. The 5-hydroxymethyl metabolite is not extensively protein bound, with unbound fraction concentrations averaging 36% ± 4.0%. The blood to serum ratio of tolterodine and the 5-hydroxymethyl metabolite averages 0.6 and 0.8, respectively, indicating that these compounds do not distribute extensively into erythrocytes. The volume of distribution of tolterodine following administration of a 1.28 mg intravenous dose is 113 ± 26.7 L. Metabolism: Tolterodine is extensively metabolized by the liver following oral dosing. The primary metabolic route involves the oxidation of the 5-methyl group and is mediated by the cytochrome P450 2D6 (CYP2D6) and leads to the formation of a pharmacologically active 5-hydroxymethyl metabolite. Further metabolism leads to formation of the 5-carboxylic acid and N-dealkylated 5-carboxylic acid metabolites, which account for 51% ± 14% and 29% ± 6.3% of the metabolites recovered in the urine, respectively. Variability in Metabolism: A subset (about 7%) of the population is devoid of CYP2D6, the enzyme responsible for the formation of the 5-hydroxymethyl metabolite of tolterodine. The identified pathway of metabolism for these individuals ("poor metabolizers") is dealkylation via cytochrome P450 3A4 (CYP3A4) to N-dealkylated tolterodine. The remainder of the population is referred to as "extensive metabolizers." Pharmacokinetic studies revealed that tolterodine is metabolized at a slower rate in poor metabolizers than in extensive metabolizers; this results in significantly higher serum concentrations of tolterodine and in negligible concentrations of the 5-hydroxymethyl metabolite. Excretion: Following administration of a 5 mg oral dose of 14 C-tolterodine solution to healthy volunteers, 77% of radioactivity was recovered in urine and 17% was recovered in feces in 7 days. Less than 1% (<2.5% in poor metabolizers) of the dose was recovered as intact tolterodine, and 5% to 14% (<1% in poor metabolizers) was recovered as the active 5-hydroxymethyl metabolite. A summary of mean (± standard deviation) pharmacokinetic parameters of tolterodine immediate release and the 5-hydroxymethyl metabolite in extensive (EM) and poor (PM) metabolizers is provided in Table 1. These data were obtained following single and multiple doses of tolterodine 4 mg administered twice daily to 16 healthy male volunteers (8 EM, 8 PM). Table 1. Summary of Mean (±SD) Pharmacokinetic Parameters of Tolterodine and its Active Metabolite (5-hydroxymethyl metabolite) in Healthy Volunteers Tolterodine 5-Hydroxymethyl Metabolite Phenotype CYP2D6) t max (h) C max * (μg/L ) C avg * (μg/L) t 1/2 (h) CL/F (L/h ) t max (h ) C max * (μg/L ) C avg * (μg/L) t 1/2 (h) Single-dose EM PM 1.6±1.5 1.4±0.5 1.6±1.2 10±4.9 0.50±0.35 8.3±4.3 2.0±0.7 6.5±1.6 534±697 17±7.3 1.8±1.4 † 1.8±0.7 † 0.62±0.26 † 3.1±0.7 † Multiple-dose EM PM 1.2±0.5 1.9±1.0 2.6±2.8 19±7.5 0.58±0.54 12±5.1 2.2±0.4 9.6±1.5 415±377 11±4.2 1.2±0.5 † 2.4±1.3 † 0.92±0.46 † 2.9±0.4 † * Parameter was dose-normalized from 4 mg to 2 mg. C max = Maximum plasma concentration; t max = Time of occurrence of C max ; C avg = Average plasma concentration; t 1/2 = Terminal elimination half-life; CL/F = Apparent oral clearance. EM = Extensive metabolizers; PM = Poor metabolizers. † = not applicable. Pharmacokinetics in Special Populations Age: In Phase 1, multiple-dose studies in which tolterodine immediate release 4 mg (2 mg bid) was administered, serum concentrations of tolterodine and of the 5-hydroxymethyl metabolite were similar in healthy elderly volunteers (aged 64 through 80 years) and healthy young volunteers (aged less than 40 years). In another Phase 1 study, elderly volunteers (aged 71 through 81 years) were given tolterodine immediate release 2 or 4 mg (1 or 2 mg bid). Mean serum concentrations of tolterodine and the 5-hydroxymethyl metabolite in these elderly volunteers were approximately 20% and 50% higher, respectively, than reported in young healthy volunteers. However, no overall differences were observed in safety between older and younger patients on tolterodine in Phase 3, 12-week, controlled clinical studies; therefore, no tolterodine dosage adjustment for elderly patients is recommended (see PRECAUTIONS, Geriatric Use ). Pediatric: The pharmacokinetics of tolterodine have not been established in pediatric patients. Gender: The pharmacokinetics of tolterodine immediate release and the 5-hydroxymethyl metabolite are not influenced by gender. Mean C max of tolterodine (1.6 µg/L in males versus 2.2 µg/L in females) and the active 5-hydroxymethyl metabolite (2.2 µg/L in males versus 2.5 µg/L in females) are similar in males and females who were administered tolterodine immediate release 2 mg. Mean AUC values of tolterodine (6.7 µg•h/L in males versus 7.8 µg•h/L in females) and the 5-hydroxymethyl metabolite (10 µg•h/L in males versus 11 µg•h/L in females) are also similar. The elimination half-life of tolterodine for both males and females is 2.4 hours, and the half-life of the 5-hydroxymethyl metabolite is 3.0 hours in females and 3.3 hours in males. Race: Pharmacokinetic differences due to race have not been established. Renal Insufficiency: Renal impairment can significantly alter the disposition of tolterodine immediate release and its metabolites. In a study conducted in patients with creatinine clearance between 10 and 30 mL/min, tolterodine immediate release and the 5-hydroxymethyl metabolite levels were approximately 2–3 fold higher in patients with renal impairment than in healthy volunteers. Exposure levels of other metabolites of tolterodine (e.g., tolterodine acid, N -dealkylated tolterodine acid, N -dealkylated tolterodine, and N-dealkylated hydroxylated tolterodine) were significantly higher (10–30 fold) in rena