About This Medication
11 DESCRIPTION Mirabegron extended-release tablet for oral use is a beta-3 adrenergic agonist. The chemical name of mirabegron is 2-(2-Amino-1,3-thiazol-4-yl)-N-[4-(2-{([(2R)-2-hydroxy-2-phenylethyl] amino}ethyl)phenyl] acetamide having an empirical formula of C 21 H 24 N 4 O 2 S and a molecular weight of 396.51. The structural formula of mirabegron is: Mirabegron is an off-white to light yellow colored powder. It is practically insoluble in water. It is soluble in methanol and dimethyl sulfoxide. Each mirabegron extended-release tablet for oral use contains either 25 mg or 50 mg of mirabegron and the following inactive ingredients: butylated hydroxytoluene, D&C Yellow No.10 Aluminum Lake, FD&C Yellow No. 6, hydroxy propyl cellulose, hypromellose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polyethylene oxide, titanium dioxide, triacetin.
適応症と用法
1 INDICATIONS AND USAGE Mirabegron extended-release tablets are beta-3 adrenergic agonist indicated for the treatment of: Overactive bladder (OAB) in adult patients with symptoms of urge urinary incontinence, urgency, and urinary frequency. ( 1.1 ) 1.1 Adult Overactive Bladder (OAB) Mirabegron Extended-Release Tablets Monotherapy Mirabegron extended-release tablets are indicated for the treatment of OAB in adult patients with symptoms of urge urinary incontinence, urgency, and urinary frequency. Pediatric use information is approved for Astellas Pharma Global Development, Inc.'s MYRBETRIQ (mirabegron extended-release tablets). However, due to Astellas Pharma Global Development, Inc.'s marketing exclusivity rights, this drug product is not labeled with that information.
作用のしくみ
12.1 Mechanism of Action Mirabegron is an agonist of the human beta-3 adrenergic receptor (AR) as demonstrated by in vitro laboratory experiments using the cloned human beta-3 AR. Mirabegron relaxes the detrusor smooth muscle during the storage phase of the urinary bladder fill-void cycle by activation of beta-3 AR which increases bladder capacity. Although mirabegron showed very low intrinsic activity for cloned human beta-1 AR and beta-2 AR, results in humans indicate that beta-1 AR stimulation occurred at a mirabegron dose of 200 mg.
用量と投与方法
2 DOSAGE AND ADMINISTRATION Mirabegron extended-release tablets and mirabegron for extended-release oral suspension are two different products and they are not substitutable on a milligram-per-milligram basis. Select the recommended product (mirabegron extended-release tablets or mirabegron for extended-release oral suspension) based on the indication. OAB in Adults The recommended starting dose of mirabegron extended-release tablets is 25 mg orally once daily. ( 2.2 ) After 4 to 8 weeks, the mirabegron extended-release tablets dose may be increased to 50 mg orally once daily. ( 2.2 ) Adult Patients with Renal or Hepatic Impairment: Refer to the full prescribing information for recommended dosage. ( 2.4 ) Administration Mirabegron Extended-Release Tablets: Adult patients: Swallow mirabegron extended-release tablets whole with water. Do not chew, divide, or crush. Take with or without food. ( 2.7 ) 2.1 Important Dosage Information Mirabegron extended-release tablets and mirabegron for extended-release oral suspension are two different products and they are not substitutable on a milligram-per milligram basis: Select the recommended product (mirabegron extended-release tablets or mirabegron for extended-release oral suspension) based on the indication [see Indications and Usage ( 1 )] . 2.2 Recommended Dosage for Adult Patients with OAB Mirabegron Extended-Release Tablets Monotherapy The recommended starting dosage of mirabegron extended-release tablets is 25 mg orally once daily. If needed, increase to the maximum dosage of mirabegron extended-release tablets 50 mg orally once daily after 4 to 8 weeks. For administration instructions, see Dosage and Administration ( 2.7 ) . Pediatric use information is approved for Astellas Pharma Global Development, Inc.'s MYRBETRIQ (mirabegron extended-release tablets). However, due to Astellas Pharma Global Development, Inc.'s marketing exclusivity rights, this drug product is not labeled with that information 2.4 Recommended Dosage in Adult Patients with Renal or Hepatic Impairment Dosage in Adults with Renal Impairment The recommended dosage of mirabegron extended-release tablets (administered orally once daily) in adult patients with renal impairment is described in Table 2 [see Use in Specific Populations 8.6 )]. For administration instructions, see Dosage and Administration ( 2.7 ). Table 2: Mirabegron Extended-Release Tablets Recommended Dosage in Adult Patients with Renal Impairment (Administered Orally Once Daily) Estimated GFR Estimated GFR using the modification of diet in renal disease (MDRD) formula. Starting Dose Maximum Dose eGFR 30 to 89 mL/min/1.73 m 2 25 mg 50 mg eGFR 15 to 29 mL/min/1.73 m 2 25 mg 25 mg eGFR < 15 mL/min/1.73 m 2 or requiring dialysis Not recommended Dosage in Adults with Hepatic Impairment The recommended dosage of mirabegron extended-release tablets (administered orally once daily) in adult patients with hepatic impairment is described in Table 3 [see Use in Specific Populations ( 8.7 )]. For administration instructions, see Dosage and Administration ( 2.7 ). Table 3: Mirabegron Extended-Release Tablets Recommended Dosage in Adult Patients with Hepatic Impairment (Administered Orally Once Daily) Hepatic Impairment Classification Starting Dose Maximum Dose Child-Pugh Class A (Mild hepatic impairment) 25 mg 50 mg Child-Pugh Class B (Moderate hepatic impairment) 25 mg 25 mg Child-Pugh Class C (Severe hepatic impairment) Not Recommended Pediatric use information is approved for Astellas Pharma Global Development, Inc.'s MYRBETRIQ (mirabegron extended-release tablets). However, due to Astellas Pharma Global Development, Inc.'s marketing exclusivity rights, this drug product is not labeled with that information. 2.7 Administration Instructions Mirabegron Extended-Release Tablets Adult patients: Swallow mirabegron extended-release tablets whole with water. Do not chew, divide, or crush. Take with or without food. 2.8 Missed Dose Instruct patients to take any missed doses as soon as they remember, unless more than 12 hours have passed since the missed dose. If more than 12 hours have passed, the missed dose can be skipped, and the next dose should be taken at the usual time.
Side Effects Overview
6 ADVERSE REACTIONS Most commonly reported adverse reactions with mirabegron monotherapy in adult patients with OAB (> 2% and > placebo) were hypertension, nasopharyngitis, urinary tract infection, and headache. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Lupin Pharmaceuticals, Inc. at 1-800-399-2561 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. The following adverse reactions are discussed in more detail in other sections of the labeling. Hypertension [see Warnings and Precautions ( 5.1 )] Urinary Retention [see Warnings and Precautions ( 5.2 )] Angioedema [see Warnings and Precautions ( 5.3 )] 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 clinical practice. Mirabegron Extended-Release Tablets Monotherapy for Adult OAB In three, 12-week, double-blind, placebo-controlled, safety and efficacy studies in patients with OAB (Studies 1, 2, and 3), mirabegron extended-release tablets were evaluated for safety in 2736 patients [see Clinical Studies ( 14.1 )] . Study 1 also included an active control. For the combined Studies 1, 2, and 3, 432 patients received mirabegron extended-release tablets 25 mg, 1375 received mirabegron extended-release tablets 50 mg, and 929 received mirabegron extended-release tablets 100 mg once daily. In these studies, the majority of the patients were Caucasian (94%) and female (72%) with a mean age of 59 years (range 18 to 95 years). Mirabegron extended-release tablets were also evaluated for safety in 1632 patients who received mirabegron extended-release tablets 50 mg once daily (n=812 patients) or mirabegron extended-release tablets 100 mg (n=820 patients) in a 1-year, randomized, fixed-dose, double-blind, active-controlled, safety study in patients with OAB (Study 4). Of these patients, 731 received mirabegron extended-release tablets in a previous 12-week study. In Study 4, 1385 patients received mirabegron extended-release tablets continuously for at least 6 months, 1311 patients received mirabegron extended-release tablets for at least 9 months, and 564 patients received mirabegron extended-release tablets for at least 1 year. The most frequent adverse events (0.2%) leading to discontinuation in Studies 1, 2, and 3 for the 25 mg or 50 mg dose were nausea, headache, hypertension, diarrhea, constipation, dizziness, and tachycardia. Atrial fibrillation (0.2%) and prostate cancer (0.1%) were reported as serious adverse events by more than 1 patient and at a rate greater than placebo. Table 8 lists the adverse reactions, derived from all adverse events, that were reported in Studies 1, 2, and 3 at an incidence greater than placebo and in 1% or more of patients treated with mirabegron extended-release tablets 25 mg or 50 mg once daily for up to 12 weeks. The most commonly reported adverse reactions (greater than 2% of mirabegron extended-release tablets patients and greater than placebo) were hypertension, nasopharyngitis, urinary tract infection, and headache. Table 8: Percentages of Patients with Adverse Reactions, Derived from All Adverse Events, Exceeding Placebo Rate and Reported in ≥ 1% of OAB Patients Treated with Mirabegron Extended-Release Tablets, 25 mg or 50 mg Once Daily in Studies 1, 2, and 3 Adverse Reaction Placebo (%) Mirabegron Extended- Release Tablets 25 mg (%) Mirabegron Extended- Release Tablets 50 mg (%) Number of Patients 1380 432 1375 Hypertension Includes reports of blood pressure above the normal range, and BP increased from baseline, occurring predominantly in subjects with baseline hypertension. 7.6 11.3 7.5 Nasopharyngitis 2.5 3.5 3.9 Urinary Tract Infection 1.8 4.2 2.9 Headache 3.0 2.1 3.2 Constipation 1.4 1.6 1.6 Upper Respiratory Tract Infection 1.7 2.1 1.5 Arthralgia 1.1 1.6 1.3 Diarrhea 1.3 1.2 1.5 Tachycardia 0.6 1.6 1.2 Abdominal Pain 0.7 1.4 0.6 Fatigue 1.0 1.4 1.2 Other adverse reactions reported by less than 1% of patients treated with mirabegron extended-release tablets in Studies 1, 2, or 3 included: Cardiac disorders: Palpitations, blood pressure increased [see Clinical Pharmacology ( 12.2 )] Eye disorders: Glaucoma [see Clinical Pharmacology ( 12.2 )] Gastrointestinal disorders: Dyspepsia, gastritis, abdominal distension Infections and Infestations: Sinusitis, rhinitis Investigations: GGT increased, AST increased, ALT increased, LDH increased Renal and urinary disorders: Nephrolithiasis, bladder pain Reproductive system and breast disorders: Vulvovaginal pruritus, vaginal infection Skin and subcutaneous tissue disorders: Urticaria, leukocytoclastic vasculitis, rash, pruritus, purpura, lip edema Table 9 lists the rates of the most commonly reported adverse reactions, derived from all adverse events in patients treated with mirabegron extended-release tablets 50 mg for up to 52 weeks in Study 4. The most commonly reported adverse reactions (>3% of mirabegron extended-release tablets patients) were hypertension, urinary tract infection, headache, and nasopharyngitis. Table 9: Percentages of Patients with Adverse Reactions, Derived from All Adverse Events, Reported in > 2% of OAB Patients Treated with Mirabegron Extended-Release Tablets 50 mg Once Daily in Study 4 Adverse Reaction Mirabegron Extended-Release Tablets 50 mg (%) Active Control (%) Number of Patients 812 812 Hypertension 9.2 9.6 Urinary Tract Infection 5.9 6.4 Headache 4.1 2.5 Nasopharyngitis 3.9 3.1 Back Pain 2.8 1.6 Constipation 2.8 2.7 Dry Mouth 2.8 8.6 Dizziness 2.7 2.6 Sinusitis 2.7 1.5 Influenza 2.6 3.4 Arthralgia 2.1 2.0 Cystitis 2.1 2.3 In Study 4, in patients treated with mirabegron extended-release tablets 50 mg once daily, adverse reactions leading to discontinuation reported by more than 2 patients and at a rate greater than active control included: constipation (0.9%), headache (0.6%), dizziness (0.5%), hypertension (0.5%), dry eyes (0.4%), nausea (0.4%), vision blurred (0.4%), and urinary tract infection (0.4%). Serious adverse events reported by at least 2 patients and exceeding active control included cerebrovascular accident (0.4%) and osteoarthritis (0.2%). Serum ALT/AST increased from baseline by greater than 10-fold in 2 patients (0.3%) taking mirabegron extended-release tablets 50 mg; and these markers subsequently returned to baseline while both patients continued mirabegron extended-release tablets. In Study 4, serious adverse events of neoplasm were reported by 0.1%, 1.3%, and 0.5% of patients treated with mirabegron extended-release tablets 50 mg, mirabegron extended-release tablets 100 mg, and active control once daily, respectively. Neoplasms reported by 2 patients treated with mirabegron extended-release tablets 100 mg included breast cancer, lung neoplasm malignant, and prostate cancer. A causal relationship between mirabegron and these reported neoplasms has not been established. In a separate clinical study in Japan, a single case was reported as Stevens-Johnson syndrome with increased serum ALT, AST, and bilirubin in a patient taking mirabegron extended-release tablets 100 mg as well as an herbal medication (Kyufu Gold). Pediatric use information is approved for Astellas Pharma Global Development, Inc.'s MYRBETRIQ (mirabegron extended-release tablets). However, due to Astellas Pharma Global Development, Inc.'s marketing exclusivity rights, this drug product is not labeled with that information. 6.2 Postmarketing Experience The following adverse reactions have been identified during post-approval use of mirabegron extended-release tablets. 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. The following events have been reported in association with mirabegron use in worldwide postmarketing experience: Cardiac disorders: Atrial fibrillation Gastrointestinal disorders: Nausea, constipation, diarrhea Nervous system disorders: Dizziness, headache There have been postmarketing reports of confusion, hallucinations, insomnia, and anxiety in patients taking mirabegron. The majority of these patients had pre-existing medical conditions or concomitant medications that may cause confusion, hallucinations, insomnia, and anxiety. A causal relationship between mirabegron and these disorders has not been established. Skin and subcutaneous tissue disorders: Angioedema of the face, lips, tongue, and larynx, with or without respiratory symptoms [see Warnings and Precautions ( 5.3 )] ; pruritus Renal and urinary disorders: Urinary retention [see Warnings and Precautions ( 5.2 )]
警告と注意事項
5 WARNINGS AND PRECAUTIONS Increases in Blood Pressure : Can increase blood pressure in adult patients. Periodically monitor blood pressure, especially in hypertensive patients. Mirabegron extended-release tablets are not recommended in patients with severe uncontrolled hypertension. ( 5.1 ) Urinary Retention in Patients With Bladder Outlet Obstruction and in Patients Taking Muscarinic Antagonist Drugs for Overactive Bladder : Administer with caution in these patients because of risk of urinary retention. ( 5.2 ) Angioedema : Angioedema of the face, lips, tongue, and/or larynx has been reported with mirabegron. ( 5.3 , 6.2 ) 5.1 Increases in Blood Pressure Increases in Blood Pressure in Adults Mirabegron extended-release tablets can increase blood pressure. Periodic blood pressure determinations are recommended, especially in hypertensive patients. Mirabegron extended-release tablets are not recommended for use in patients with severe uncontrolled hypertension (defined as systolic blood pressure greater than or equal to 180 mm Hg and/or diastolic blood pressure greater than or equal to 110 mm Hg) [see Clinical Pharmacology ( 12.2 )]. In two, randomized, placebo-controlled, healthy adult volunteer studies, mirabegron extended-release tablets were associated with dose-related increases in supine blood pressure. In these studies, at the maximum recommended dose of 50 mg, the mean maximum increase in systolic/diastolic blood pressure was approximately 3.5/1.5 mm Hg greater than placebo. In contrast, in adult OAB patients in clinical trials, mirabegron extended-release tablets, taken as monotherapy, the mean increase in systolic and diastolic blood pressure at the maximum recommended mirabegron dose of 50 mg was approximately 0.5 to 1 mm Hg greater than placebo. Worsening of pre-existing hypertension was reported infrequently in patients taking mirabegron extended-release tablets. Increases in Blood Pressure in Pediatric Patients 3 Years and Older Mirabegron extended-release tablets can increase blood pressure in pediatric patients. Blood pressure increases may be larger in children (3 to less than 12 years of age) than in adolescents (12 to less than 18 years of age). Periodic blood pressure determinations are recommended. Mirabegron extended-release tablets is not recommended for use in pediatric patients with severe uncontrolled hypertension, defined as a systolic and/or diastolic blood pressure above the 99 th percentile plus 5 mm Hg for age, sex, and stature using appropriate reference values. Pediatric use information is approved for Astellas Pharma Global Development, Inc.'s MYRBETRIQ (mirabegron extended-release tablets). However, due to Astellas Pharma Global Development, Inc.'s marketing exclusivity rights, this drug product is not labeled with that information. 5.2 Urinary Retention in Patients with Bladder Outlet Obstruction and in Patients Taking Muscarinic Antagonist Medications for OAB In patients taking mirabegron extended-release tablets, urinary retention has been reported to occur in patients with bladder outlet obstruction (BOO) and in patients taking muscarinic antagonist medications for the treatment of OAB. A controlled clinical safety study in patients with BOO did not demonstrate increased urinary retention in patients treated with mirabegron; however, mirabegron extended-release tablets should still be administered with caution to patients with clinically significant BOO. For example, monitor these patients for signs and symptoms of urinary retention. Mirabegron extended-release tablets should also be administered with caution to patients taking muscarinic antagonist medications for the treatment of OAB [see Clinical Pharmacology ( 12.2 )] . 5.3 Angioedema Angioedema of the face, lips, tongue, and/or larynx has been reported with mirabegron 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. If involvement of the tongue, hypopharynx, or larynx occurs, promptly discontinue mirabegron extended-release tablets and provide appropriate therapy and/or measures necessary to ensure a patent airway [see Adverse Reactions ( 6.2 )] . 5.4 Patients Taking Drugs Metabolized by CYP2D6 Since mirabegron extended-release tablet is a moderate CYP2D6 inhibitor, the systemic exposure to CYP2D6 substrates is increased when coadministered with mirabegron extended-release tablet. Therefore, appropriate monitoring and dose adjustment may be necessary, especially with narrow therapeutic index drugs metabolized by CYP2D6 [see Drug Interactions ( 7.1 ) and Clinical Pharmacology ( 12.3 )] .
禁忌
4 CONTRAINDICATIONS Hypersensitivity to mirabegron or any inactive ingredients. ( 4 ) Mirabegron extended-release tablets are contraindicated in patients with known hypersensitivity reactions to mirabegron or any inactive ingredients of the tablet [see Adverse Reactions ( 6.1 , 6.2 )] .
薬物動態
12.3 Pharmacokinetics Absorption Mirabegron Extended-Release Tablets Monotherapy for Adult OAB: After oral administration of mirabegron in healthy volunteers, mirabegron was absorbed to reach maximum plasma concentrations (C max ) at approximately 3.5 hours. The absolute bioavailability increased from 29% at a dose of 25 mg to 35% at a dose of 50 mg. Mean C max and AUC increased more than dose proportionally. This relationship was more apparent at doses above 50 mg. In the overall population of males and females, a 2-fold increase in dose from 50 mg to 100 mg mirabegron increased C max and AUC tau by approximately 2.9-and 2.6-fold, respectively, whereas a 4-fold increase in dose from 50 to 200 mg mirabegron increased C max and AUC tau by approximately 8.4-and 6.5-fold. Steady-state concentrations were achieved within 7 days of once daily dosing with mirabegron. After once daily administration, plasma exposure of mirabegron at steady-state was approximately double that seen after a single dose. Effect of Food: Mirabegron Extended-Release Tablets Monotherapy for Adult OAB: There were no clinically significant differences in mirabegron pharmacokinetics when administered with or without food in adult patients. Distribution Mirabegron Extended-Release Tablets Monotherapy for Adult OAB: Mirabegron is extensively distributed in the body. The volume of distribution at steady-state (V ss ) is approximately 1670 L following intravenous administration. Mirabegron is bound (approximately 71%) to human plasma proteins, and shows moderate affinity for albumin and alpha-1 acid glycoprotein. Mirabegron distributes to erythrocytes. Based on an in vitro study, erythrocyte concentrations of 14 C-mirabegron were about 2-fold higher than in plasma. Elimination Mirabegron Extended-Release Tablets Monotherapy for Adult OAB: The terminal elimination half-life (t 1/2 ) of mirabegron is approximately 50 hours in patients. Metabolism Mirabegron is metabolized via multiple pathways involving dealkylation, oxidation, (direct) glucuronidation, and amide hydrolysis. Mirabegron is the major circulating component following a single dose of 14 C-mirabegron. Two major metabolites were observed in human plasma and are phase 2 glucuronides representing 16% and 11% of total exposure, respectively. These metabolites are not pharmacologically active toward beta-3 adrenergic receptor. Although, in vitro studies suggest a role for CYP2D6 and CYP3A4 in the oxidative metabolism of mirabegron, in vivo results indicate that these isozymes play a limited role in the overall elimination. In healthy subjects who were genotypically poor metabolizers of CYP2D6, mean C max and AUC tau were approximately 16% and 17% higher than in extensive metabolizers of CYP2D6, respectively. In vitro and ex vivo studies have shown the involvement of butylcholinesterase, uridine diphospho-glucuronosyltransferases (UGT), and possibly alcohol dehydrogenase in the metabolism of mirabegron, in addition to CYP3A4 and CYP2D6. Excretion Mirabegron Extended-Release Tablets Monotherapy for Adult OAB: Total body clearance (CL tot ) from plasma is approximately 57 L/h following intravenous administration. Renal clearance (CL R ) is approximately 13 L/h, which corresponds to nearly 25% of CL tot . Renal elimination of mirabegron is primarily through active tubular secretion along with glomerular filtration. The urinary elimination of unchanged mirabegron is dose-dependent and ranges from approximately 6.0% after a daily dose of 25 mg to 12.2% after a daily dose of 100 mg. Following the administration of 160 mg 14 C-mirabegron solution to healthy volunteers, approximately 55% of the radioactivity dose was recovered in the urine and 34% in the feces. Approximately 25% of unchanged mirabegron was recovered in urine and 0% in feces. Specific Populations Geriatric Patients: The C max and AUC of mirabegron following multiple oral doses in elderly volunteers (≥ 65 years) were similar to those in younger volunteers (18 to 45 years) [see Use in Specific Populations ( 8.5 )] . Gender: Mirabegron Extended-Release Tablets Monotherapy for Adult OAB The C max and AUC of mirabegron were approximately 40% to 50% higher in females than in males. When corrected for differences in body weight, the mirabegron systemic exposure was 20% to 30% higher in females compared to males. Race: The pharmacokinetics of mirabegron were comparable between Caucasians and African-American Blacks. Cross studies comparison showed that the exposure in Japanese subjects were higher than that in North American subjects. However, when the C max and AUC were normalized for dose and body weight, the difference was smaller. Patients with Renal Impairment: Following single-dose administration of 100 mg mirabegron in adult volunteers with mild renal impairment (eGFR 60 to 89 mL/min/1.73 m 2 as estimated by MDRD), mean mirabegron C max and AUC were increased by 6% and 31% relative to adult volunteers with normal renal function. In adult volunteers with moderate renal impairment (eGFR 30 to 59 mL/min/1.73 m 2 ), C max and AUC were increased by 23% and 66%, respectively. In adult volunteers with severe renal impairment (eGFR 15 to 29 mL/min/1.73 m 2 ), mean C max and AUC values were 92% and 118% higher compared to healthy subjects with normal renal function. Mirabegron has not been studied in adult patients with End-Stage Renal Disease (ESRD) (eGFR less than 15 mL/min/1.73 m 2 ) or adult patients requiring dialysis. Patients with Hepatic Impairment : Following single-dose administration of 100 mg mirabegron in adult volunteers with mild hepatic impairment (Child- Pugh Class A), mean mirabegron C max and AUC were increased by 9% and 19%, relative to adult volunteers with normal hepatic function. In adult volunteers with moderate hepatic impairment (Child-Pugh Class B), mean C max and AUC values were 175% and 65% higher. Mirabegron has not been studied in adult patients with severe hepatic impairment (Child-Pugh Class C). Drug Interaction Studies In Vitro Studies: Effect of Other Drugs on Mirabegron Mirabegron is transported and metabolized through multiple pathways. Mirabegron is a substrate for CYP3A4, CYP2D6, butyrylcholinesterase, UGT, the efflux transporter P-glycoprotein (P-gp), and the influx organic cation transporters (OCT) OCT1, OCT2, and OCT3. Sulfonylurea hypoglycemic agents glibenclamide (a CYP3A4 substrate), gliclazide (a CYP2C9 and CYP3A4 substrate), and tolbutamide (a CYP2C9 substrate) did not affect the in vitro metabolism of mirabegron. Effect of Mirabegron on Other Drugs Studies of mirabegron using human liver microsomes and recombinant human CYP enzymes showed that mirabegron is a moderate and time-dependent inhibitor of CYP2D6 and a weak inhibitor of CYP3A. Mirabegron is unlikely to inhibit the metabolism of coadministered drugs metabolized by the following cytochrome P450 enzymes: CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19 and CYP2E1 because mirabegron did not inhibit the activity of these enzymes at clinically relevant concentrations. Mirabegron did not induce CYP1A2 or CYP3A. Mirabegron inhibited P-gp-mediated drug transport at high concentrations. Mirabegron is predicted not to cause clinically relevant inhibition of OCT-mediated drug transport. Mirabegron did not affect the metabolism of glibenclamide or tolbutamide. In Vivo Studies: Mirabegron Extended-Release Tablets Monotherapy for Adult OAB The effect of coadministered drugs on the pharmacokinetics of mirabegron and the effect of mirabegron on the pharmacokinetics of coadministered drugs was studied after single and multiple doses of mirabegron. Most drug-drug interactions (DDI) were studied using mirabegron 100 mg extended-release tablets. However, interaction studies of mirabegron with metoprolol and with metformin were studied using mirabegron 160 mg immediate-release (IR) tablets. The effect of ketoconazole, rifampicin, solifenacin succinate, tamsulosin, and metformin on systemic mirabegron exposure is shown in Figure 1. The effect of mirabegron on metoprolol, desipramine, combined oral contraceptive-COC (ethinyl estradiol-EE, levonorgestrel-LNG), solifenacin succinate, digoxin, warfarin, tamsulosin, and metformin is shown in Figure 2. In these studies, the largest increase in mirabegron systemic exposure was seen in the ketoconazole DDI study. As a potent CYP3A4 inhibitor, ketoconazole increased mirabegron C max by 45% and mirabegron AUC by 80% after multiple dose administration of 400 mg of ketoconazole for 9 days prior to the administration of a single dose of 100 mg mirabegron in 23 male and female healthy subjects. As a moderate CYP2D6 inhibitor, mirabegron increased the systemic exposure to metoprolol and desipramine: Mirabegron increased the C max of metoprolol by 90% and metoprolol AUC by 229% after multiple doses of 160 mg mirabegron IR tablets once daily for 5 days and a single dose of 100 mg metoprolol tablet in 12 healthy male subjects administered before and concomitantly with mirabegron. Mirabegron increased the C max of desipramine by 79% and desipramine AUC by 241% after multiple dose administration of 100 mg mirabegron once daily for 18 days and a single dose of 50 mg desipramine before and concomitantly with mirabegron in 28 male and female healthy subjects. Figures 1 and 2 show the magnitude of these interactions on the pharmacokinetic parameters and the recommendations for dose adjustment, if any: Figure 1: The Effect of Coadministered Drugs on Exposure of Mirabegron Extended-Release Tablets and Dose Recommendation (1) Although no dose adjustment is recommended with solifenacin succinate or tamsulosin based on the lack of pharmacokinetic interaction, mirabegron extended-release tablets should be administered with caution to patients taking muscarinic antagonist medications for the treatment of OAB and in patients with clinically significant BOO because of the risk of urinary retention [see Warnings and Precautions ( 5.2 )] . Figure 2: The Effect of Mirabegron Extended-Release Tablets on Exposure of Coadministered Medication (1) Since mirabegron is a moderate CYP2D6 inhibitor, the systemic exposure to CYP2D6 substrates such as metoprolol and desipramine is increased when coadministered with mirabegron. Therefore, appropriate monitoring and dose adjustment may be necessary, especially with narrow therapeutic index CYP2D6 substrates, such as thioridazine, flecainide, and propafenone [see Warnings and Precautions ( 5.4 ) and Drug Interactions ( 7.1 )] . (2) For patients who are initiating a combination of mirabegron and digoxin, the lowest dose for digoxin should initially be prescribed. Serum digoxin concentrations should be monitored and used for titration of the digoxin dose to obtain the desired clinical effect [see Drug Interactions ( 7.2 )] . (3) Warfarin was administered as a single 25 mg dose of the racemate (a mixture of R-warfarin and S-warfarin). Based on this single-dose study, mirabegron had no effect on the warfarin pharmacodynamic endpoints such as INR and prothrombin time. However, the effect of mirabegron on multiple doses of warfarin and on warfarin pharmacodynamic end points such as INR and prothrombin time has not been fully investigated [see Drug Interactions ( 7.3 )] . (4) Although no dose adjustment is recommended with solifenacin succinate or tamsulosin based on the lack of pharmacokinetic interaction, mirabegron extended-release tablets should be administered with caution to patients taking muscarinic antagonist medications for the treatment of OAB and in BOO because of the risk of urinary retention [see Warnings and Precautions ( 5.2 )] . Pediatric use information is approved for Astellas Pharma Global Development, Inc.'s MYRBETRIQ (mirabegron extended-release tablets). However, due to Astellas Pharma Global Development, Inc.'s marketing exclusivity rights, this drug product is not labeled with that information.