Dexmethylphenidate Hydrochloride

1 INDICATIONS AND USAGE Dexmethylphenidate hydrochloride extended-release is indicated for the treatment of Attention Deficit Hyperactivity Disorder (ADHD) [see Clinical Studies ( 14 )]. Dexmethylphenidate hydrochloride extended-release is a central nervous system (CNS) stimulant indicated for the treatment of Attention Deficit Hyperactivity Disorder (ADHD) ( 1 ).

2 DOSAGE AND ADMINISTRATION Patients new to methylphenidate: Recommended starting dose is 5 mg once daily for pediatric patients and 10 mg once daily for adults with or without food in the morning ( 2.2) . Patients currently on methylphenidate: Dexmethylphenidate hydrochloride extended-release dosage is half (1/2) the current total daily dosage of methylphenidate ( 2.2 ). Patients currently on dexmethylphenidate immediate-release tablets: Give the same daily dose of dexmethylphenidate hydrochloride extended-release ( 2.2 ). Titrate weekly in increments of 5 mg in pediatric patients and 10 mg in adult patients ( 2.2 ). Maximum recommended daily dose: 30 mg in pediatric patients and 40 mg in adults ( 2.2 ). Capsules may be swallowed whole or opened and the entire contents sprinkled on applesauce ( 2.3 ). 2.1 Pretreatment Screening Prior to treating patients with dexmethylphenidate hydrochloride extended-release, assess: for the presence of cardiac disease (i.e., perform a careful history, family history of sudden death or ventricular arrhythmia, and physical exam) [see Warnings and Precautions ( 5.2 )]. the family history and clinically evaluate patients for motor or verbal tics or Tourette’s syndrome before initiating dexmethylphenidate hydrochloride extended-release [see Warnings and Precautions ( 5.10 )]. 2.2 Recommended Dosage Patients New to Methylphenidate The recommended starting dosage of dexmethylphenidate hydrochloride extended-release for patients who are not currently taking dexmethylphenidate or racemic methylphenidate, or for patients who are on stimulants other than methylphenidate are: Pediatric patients: Start with 5 mg orally once daily in the morning with or without food. Adult patients: Start with 10 mg orally once daily in the morning with or without food. Patients Currently on Methylphenidate The recommended starting dose of dexmethylphenidate hydrochloride extended-release for patients currently using methylphenidate is half (1/2) the total daily dose of racemic methylphenidate. Patients currently using dexmethylphenidate immediate-release tablets may be given the same daily dose of dexmethylphenidate hydrochloride extended-release. Titration Schedule The dose may be titrated weekly in increments of 5 mg in pediatric patients and 10 mg in adult patients. The dose should be individualized according to the needs and response of the patient. Daily doses above 30 mg in pediatrics and 40 mg in adults have not been studied and are not recommended. 2.3 Administration Instructions Dexmethylphenidate hydrochloride extended-release is administered orally and may be taken whole or the capsule may be opened and the entire contents sprinkled onto applesauce. If the patient is using the sprinkled administration method, the sprinkled applesauce should be consumed immediately; it should not be stored. Patients should take the applesauce with sprinkled beads in its entirety without chewing. The dose of a single capsule should not be divided. The contents of the entire capsule should be taken, and patients should not take anything less than one capsule per day. 2.4 Dosage Reduction and Discontinuation If paradoxical aggravation of symptoms or other adverse reactions occur, reduce the dosage, or if necessary, discontinue dexmethylphenidate hydrochloride extended-release. If improvement is not observed after appropriate dosage adjustment over a one-month period, the drug should be discontinued.

6 ADVERSE REACTIONS The following are discussed in more detail in other sections of the labeling: Abuse, Misuse, and Addiction [see Boxed Warning, Warnings and Precautions ( 5.1 ), Drug Abuse and Dependence ( 9.2 , 9.3 )] Known hypersensitivity to methylphenidate or other ingredients of dexmethylphenidate hydrochloride extended-release [see Contraindications ( 4 )] Hypertensive Crisis with Concomitant Use of Monoamine Oxidase Inhibitors [see Contraindications ( 4 ), Drug Interactions ( 7.1 )] Risks to Patients with Serious Cardiac Disease [see Warnings and Precautions ( 5.2 )] Increased Blood Pressure and Heart Rate [see Warnings and Precautions ( 5.3 )] Psychiatric Adverse Reactions [see Warnings and Precautions ( 5.4 )] Priapism [see Warnings and Precautions ( 5.5 )] Peripheral Vasculopathy, Including Raynaud’s Phenomenon [see Warnings and Precautions ( 5.6 )] Long-Term Suppression of Growth in Pediatric Patients [see Warnings and Precautions ( 5.7 )] Acute Angle Closure Glaucoma [see Warnings and Precautions ( 5.8 )] Increased Intraocular Pressure and Glaucoma [see Warnings and Precautions ( 5.9 )] Motor and Verbal Tics, and Worsening of Tourette’s Syndrome [see Warnings and Precautions ( 5.10 )] The most common adverse reactions (greater than or equal to 5% and twice the rate of placebo): Pediatric patients 6 to 17 years: dyspepsia, decreased appetite, headache, and anxiety ( 6.1 ). Adults: dry mouth, dyspepsia, headache, pharyngolaryngeal pain, and anxiety ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Endo at 1-800-828-9393 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 clinical practice. Adverse Reactions in Studies with Dexmethylphenidate Hydrochloride Extended-Release in Pediatric Patients with ADHD The safety data in this section is based on data from a 7-week controlled clinical study of dexmethylphenidate hydrochloride extended-release in 100 (103 randomized) pediatric patients with ADHD ages 6 to 17 years (ages 6 to 12, n = 86; ages 13 to 17, n = 17). This study was a randomized, double-blind, placebo-controlled, parallel-group study to evaluate the time of onset, duration of efficacy, tolerability, safety of dexmethylphenidate hydrochloride extended-release 5 mg to 30 mg/day who met The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria for ADHD [see Clinical Studies ( 14.1 )] . Most Common Adverse Reactions (incidence of greater than or equal to 5% and at least twice placebo): dyspepsia, decreased appetite, headache, and anxiety. Adverse Reactions Leading to Discontinuation : 50 of 684 (7.3%) pediatric patients treated with dexmethylphenidate immediate-release tablets experienced an adverse reaction that resulted in discontinuation. The most common reasons for discontinuation were twitching (described as motor or vocal tics), anorexia, insomnia, and tachycardia (approximately 1% each). Table 1 enumerates adverse reactions for the placebo-controlled, parallel-group study in children and adolescents with ADHD at flexible dexmethylphenidate hydrochloride extended-release doses of 5 to 30 mg/day. The table includes only those events that occurred in 5% or more of patients treated with dexmethylphenidate hydrochloride extended-release and for which the incidence in patients treated with dexmethylphenidate hydrochloride extended-release was at least twice the incidence in placebo-treated patients. Table 1: Common Adverse Reactions in Pediatric Patients (6 to 17 years of age) with ADHD System Organ Class Adverse Reaction Dexmethylphenidate Hydrochloride Extended-Release N=53 Placebo N=47 Gastrointestinal Disorders 38% 19% Dyspepsia 8% 4% Metabolism and Nutrition Disorders 34% 11% Decreased Appetite 30% 9% Nervous System Disorders 30% 13% Headache 25% 11% Psychiatric Disorders 26% 15% Anxiety 6% 0% Abbreviation: ADHD, attention deficit hyperactivity disorder. Table 2 below enumerates the incidence of dose-related adverse reactions that occurred during a fixed-dose, double-blind, placebo-controlled trial in pediatric patients with ADHD taking dexmethylphenidate hydrochloride extended-release up to 30 mg daily versus placebo. The table includes only those reactions that occurred in patients treated with dexmethylphenidate hydrochloride extended-release for which the incidence was at least 5% and greater than the incidence among placebo-treated patients. Table 2: Dose-Related Adverse Reactions in Pediatric Patients (6 to 17 years of age) with ADHD System Organ Class Adverse Reaction Dexmethylphenidate Hydrochloride Extended-Release 10 mg/day N = 64 Dexmethylphenidate Hydrochloride Extended-Release 20 mg/day N = 60 Dexmethylphenidate Hydrochloride Extended-Release 30 mg/day N = 58 Placebo N = 63 Gastrointestinal Disorders 22% 23% 29% 24% Vomiting 2% 8% 9% 0% Metabolism and Nutritional Disorders 16% 17% 22% 5% Anorexia 5% 5% 7% 0% Psychiatric Disorders 19% 20% 38% 8% Insomnia 5% 8% 17% 3% Depression 0% 0% 3% 0% Mood Swings 0% 0% 3% 2% Other Adverse Reactions Irritability 0% 2% 5% 0% Nasal Congestion 0% 0% 5% 0% Pruritus 0% 0% 3% 0% Abbreviation: ADHD, attention deficit hyperactivity disorder. Adverse Reactions in Studies with Dexmethylphenidate Hydrochloride Extended-Release in Adult Patients with ADHD The safety data in this section is based on data from a 5-week controlled clinical study of dexmethylphenidate hydrochloride extended-release in 218 adult patients (221 randomized) with ADHD ages 18 to 60 years. In this study, 101 adult patients were treated for at least 6 months. This study was a randomized, double-blind, placebo-controlled, parallel-group study to evaluate the efficacy, safety, and tolerability of dexmethylphenidate hydrochloride extended-release 20 mg, 30 mg, or 40 mg daily who met DSM-IV criteria for ADHD [see Clinical Studies ( 14.2 )] . Most Common Adverse Reactions (incidence of greater than or equal to 5% and at least twice placebo): dry mouth, dyspepsia, headache, anxiety, and pharyngolaryngeal pain. Adverse Reactions Leading to Discontinuation: During the double-blind phase of the study, 10.7% of the dexmethylphenidate hydrochloride extended-release-treated patients and 7.5% of the placebo-treated patients discontinued due to adverse reactions. Three patients (1.8%) in the dexmethylphenidate hydrochloride extended-release discontinued due to insomnia and jittery respectively; and two patients (1.2%) in the dexmethylphenidate hydrochloride extended-release discontinued due to anorexia and anxiety, respectively. Table 3 enumerates adverse reactions for the placebo-controlled, parallel-group study in adults with ADHD at fixed dexmethylphenidate hydrochloride extended-release doses of 20, 30, or 40 mg/day. The table includes only those events that occurred in 5% or more of patients in a dexmethylphenidate hydrochloride extended-release dose group and for which the incidences in patients treated with dexmethylphenidate hydrochloride extended-release appeared to increase with dose. Table 3: Dose-Related Adverse Reactions in Adult Patients (18 to 60 years of age) with ADHD System Organ Class Adverse Reaction Dexmethylphenidate Hydrochloride Extended-Release 20 mg N = 57 Dexmethylphenidate Hydrochloride Extended-Release 30 mg N = 54 Dexmethylphenidate Hydrochloride Extended-Release 40 mg N = 54 Placebo N = 53 Gastrointestinal Disorders 28% 32% 44% 19% Dry Mouth 7% 20% 20% 4% Dyspepsia 5% 9% 9% 2% Nervous System Disorders 37% 39% 50% 28% Headache 26% 30% 39% 19% Psychiatric Disorders 40% 43% 46% 30% Anxiety 5% 11% 11% 2% Respiratory, Thoracic, and Mediastinal Disorders 16% 9% 15% 8% Pharyngolaryngeal Pain 4% 4% 7% 2% Two other adverse reactions occurring in clinical trials with dexmethylphenidate hydrochloride extended-release at a frequency greater than placebo, but which were not dose related were: feeling jittery (12% and 2%, respectively) and dizziness (6% and 2%, respectively). Table 4 summarizes changes in vital signs and weight that were recorded in the adult study (N=218) of dexmethylphenidate hydrochloride extended-release in the treatment of ADHD. Table 4: Changes (Mean ± SD) in Vital Signs and Weight by Randomized Dose During Double-Blind Treatment-Adults Dexmethylphenidate Hydrochloride ER 20 mg (N=57) Dexmethylphenidate Hydrochloride ER 30 mg (N=54) Dexmethylphenidate Hydrochloride ER 40 mg (N=54) Placebo (N=53) Pulse (bpm) 3.1 ± 11.1 4.3 ± 11.7 6.0 ± 10.1 -1.4 ± 9.3 Diastolic BP (mmHg) -0.2 ± 8.2 1.2 ± 8.9 2.1 ± 8.0 0.3 ± 7.8 Weight (kg) -1.4 ± 2.0 -1.2 ± 1.9 -1.7 ± 2.3 -0.1 ± 3.9 6.2 Postmarketing Experience The following additional adverse reactions have been identified during postapproval use of dexmethylphenidate. 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. Musculoskeletal: rhabdomyolysis Immune System Disorders: hypersensitivity reactions, including angioedema and anaphylaxis Adverse Reactions Reported with All Ritalin and Dexmethylphenidate Hydrochloride Extended-Release Formulations The following adverse reactions associated with the use of all Ritalin and dexmethylphenidate hydrochloride extended-release formulations were identified in clinical trials, spontaneous reports, and literature. Because these reactions were reported voluntarily from a population of uncertain size, it is not always possible to estimate their frequency reliably or to establish a causal relationship to drug exposure. Infections and Infestations: nasopharyngitis Blood and the Lymphatic System Disorders: leukopenia, thrombocytopenia, anemia Immune System Disorders: hypersensitivity reactions, including angioedema and anaphylaxis Metabolism and Nutrition Disorders: decreased appetite, reduced weight gain, and suppression of growth during prolonged use in pediatric patients Psychiatric Disorders: insomnia, anxiety, restlessness, agitation, psychosis (sometimes with visual and tactile hallucinations), depressed mood, depression Nervous System Disorders: headache, dizziness, tremor, dyskinesia, including choreoathetoid movements, drowsiness, convulsions, cerebrovascular disorders (including vasculitis, cerebral hemorrhages and cerebrovascular accidents), serotonin syndrome in combination with serotonergic drugs Eye Disorders: blurred vision, difficulties in visual accommodation Cardiac Disorders: tachycardia, palpitations, increased blood pressure, arrhythmias, angina pectoris Respiratory, Thoracic, and Mediastinal Disorders: cough Gastrointestinal Disorders: dry mouth, nausea, vomiting, abdominal pain, dyspepsia Hepatobiliary Disorders: abnormal liver function, ranging from transaminase elevation to severe hepatic injury Skin and Subcutaneous Tissue Disorders: hyperhidrosis, pruritus, urticaria, exfoliative dermatitis, scalp hair loss, erythema multiforme rash, thrombocytopenic purpura Musculoskeletal and Connective Tissue Disorders: arthralgia, muscle cramps, rhabdomyolysis, trismus Investigations: weight loss (adult ADHD patients) Vascular Disorders: peripheral coldness, Raynaud's phenomenon Additional Adverse Reactions Reported with Other Methylphenidate Products The list below shows adverse reactions not listed with Ritalin and Dexmethylphenidate Hydrochloride Extended-Release formulations that have been reported with other methylphenidate products based on clinical trials data and post-marketing spontaneous reports. Blood and Lymphatic Disorders: pancytopenia Immune System Disorders: hypersensitivity reactions, such as auricular swelling, bullous conditions, eruptions, exanthemas Psychiatric Disorders: affect lability, mania, disorientation, libido changes Nervous System Disorders: migraine, motor and verbal tics Eye Disorders: diplopia, increased intraocular pressure, mydriasis Cardiac Disorders: sudden cardiac death, myocardial infarction, bradycardia, extrasystole, supraventricular tachycardia, ventricular extrasystole Respiratory, Thoracic, and Mediastinal Disorders: pharyngolaryngeal pain, dyspnea Gastrointestinal Disorders: diarrhea, constipation Skin and Subcutaneous Tissue Disorders: angioneurotic edema, erythema, fixed drug eruption Musculoskeletal, Connective Tissue, and Bone Disorders: myalgia, muscle twitching Renal and Urinary Disorders: hematuria Reproductive System and Breast Disorders: gynecomastia General Disorders: fatigue, hyperpyrexia Urogenital Disorders: priapism

12.3 Pharmacokinetics Absorption Dexmethylphenidate hydrochloride extended-release produces a bi-modal plasma concentration-time profile (i.e., 2 distinct peaks approximately 4 hours apart) when orally administered to healthy adults. The initial rate of absorption for dexmethylphenidate hydrochloride extended-release is similar to that of dexmethylphenidate tablets as shown by the similar rate parameters between the 2 formulations, i.e., first peak concentration (C max1 ), and time to the first peak (t max1 ), which is reached in 1.5 hours (typical range 1 to 4 hours). The mean time to the interpeak minimum (t minip) is slightly shorter, and time to the second peak (t max2 ) is slightly longer for dexmethylphenidate hydrochloride extended-release given once daily (about 6.5 hours; range, 4.5 to 7 hours) compared to dexmethylphenidate hydrochloride tablets given in 2 doses 4 hours apart (see Figure 1) , although the ranges observed are greater for dexmethylphenidate hydrochloride extended-release. Dexmethylphenidate hydrochloride extended-release given once daily exhibits a lower second peak concentration (C max2 ), higher interpeak minimum concentrations (C minip ), and fewer peak and trough fluctuations than dexmethylphenidate hydrochloride tablets given in 2 doses given 4 hours apart. This is due to an earlier onset and more prolonged absorption from the delayed-release beads (see Figure 1 ). The ratio of geometric mean of AUC (0-inf) and C max after administration of dexmethylphenidate hydrochloride extended-release given once daily are 1.02 and 0.86 respectively, to the same total dose of dexmethylphenidate hydrochloride tablets given in 2 doses 4 hours apart. The variability in C max , C min , and AUC is similar between dexmethylphenidate hydrochloride extended-release and dexmethylphenidate immediate-release tablets with approximately a 3-fold range in each. Approximately 90% of the dose is absorbed after oral administration of radiolabeled racemic methylphenidate. However, due to first pass metabolism the mean absolute bioavailability of dexmethylphenidate when administered in various formulations was 22% to 25%. Figure 1. Mean Dexmethylphenidate Plasma Concentration-Time Profiles After Administration of 1 x 20 mg Dexmethylphenidate Hydrochloride Extended-Release (n=24) Capsules and 2 x 10 mg Dexmethylphenidate Hydrochloride Immediate-Release Tablets (n=25) After single dose administration, dexmethylphenidate hydrochloride extended-release demonstrated dose proportional pharmacokinetics (PK) in the range of 5 mg to 40 mg. For patients unable to swallow the capsule, the contents may be sprinkled on applesauce and administered [see Dosage and Administration (2) ] . Distribution The plasma protein binding of dexmethylphenidate is not known; racemic methylphenidate is bound to plasma proteins by 12% to 15%, independent of concentration. Dexmethylphenidate shows a volume of distribution of 2.65 ± 1.11 L/kg. Elimination Plasma dexmethylphenidate concentrations decline monophasically following oral administration of dexmethylphenidate hydrochloride extended-release. The mean terminal elimination half-life of dexmethylphenidate was about 3 hours in healthy adults. Pediatric patients tend to have slightly shorter half-lives with means of 2 to 3 hours. Dexmethylphenidate was eliminated with a mean clearance of 0.40 ± 0.12 L/hr/kg after intravenous administration. Metabolism In humans, dexmethylphenidate is metabolized primarily via de-esterification to d-α -phenyl-piperidine acetic acid (also known as d -ritalinic acid). This metabolite has little or no pharmacological activity. There is no in vivo interconversion to the l-threo -enantiomer. Excretion After oral dosing of radiolabeled racemic methylphenidate in humans, about 90% of the radioactivity was recovered in urine. The main urinary metabolite of racemic dl -methylphenidate was dl -ritalinic acid, accountable for approximately 80% of the dose. Urinary excretion of parent compound accounted for 0.5% of an intravenous dose. Studies in Specific Populations M a le and Female Patients After administration of dexmethylphenidate hydrochloride extended-release, the first peak, (C max1 ) was on average 45% higher in women. The interpeak minimum and the second peak also tended to be slightly higher in women although the difference was not statistically significant, and these patterns remained even after weight normalization. Racial or Ethnic Groups There is insufficient experience with the use of dexmethylphenidate hydrochloride extended-release to detect ethnic variations in pharmacokinetics. Pediatric Patients The pharmacokinetics of dexmethylphenidate after dexmethylphenidate hydrochloride extended-release administration have not been studied in pediatrics less than 18 years of age. When a similar formulation of racemic methylphenidate was examined in 15 patients between 10 and 12 years of age, and 3 patients with ADHD between 7 and 9 years of age, the time to the first peak was similar, although the time until the between peak minimum, and the time until the second peak were delayed and more variable in pediatric patients compared to adults. After administration of the same dose to pediatric patients and adults, concentrations in pediatric patients were approximately twice the concentrations observed in adults. This higher exposure is almost completely due to smaller body size as no relevant age-related differences in dexmethylphenidate pharmacokinetic parameters (i.e., clearance and volume of distribution) are observed after normalization to dose and weight. Patients with Renal Impairment There is no experience with the use of dexmethylphenidate hydrochloride extended-release in patients with renal impairment. Since renal clearance is not an important route of methylphenidate elimination, renal impairment is expected to have little effect on the pharmacokinetics of dexmethylphenidate hydrochloride extended-release. Patients with Hepatic Impairment There is no experience with the use of dexmethylphenidate hydrochloride extended-release in patients with hepatic impairment. Drug Interaction Studies Methylphenidate is not metabolized by cytochrome P450 (CYP) isoenzymes to a clinically relevant extent. Inducers or inhibitors of CYPs are not expected to have any relevant impact on methylphenidate pharmacokinetics. Conversely, the d - and l -enantiomers of methylphenidate did not relevantly inhibit CYP1A2, 2C8, 2C9, 2C19, 2D6, 2E1, or 3A. Clinically, methylphenidate coadministration did not increase plasma concentrations of the CYP2D6 substrate desipramine.