Dexmethylphenidate Hydrochloride - Dexmethylphenidate Hydrochloride tablet prescribing information
WARNING: ABUSE, MISUSE, AND ADDICTION
Dexmethylphenidate hydrochloride tablets have a high potential for abuse and misuse, which can lead to the development of a substance use disorder, including addiction. Misuse and abuse of CNS stimulants, including dexmethylphenidate hydrochloride tablets, can result in overdose and death [see Overdosage (10) ] , and this risk is increased with higher doses or unapproved methods of administration, such as snorting or injection. Before prescribing dexmethylphenidate hydrochloride tablets, assess each patient's risk for abuse, misuse, and addiction. Educate patients and their families about these risks, proper storage of the drug, and proper disposal of any unused drug. Throughout dexmethylphenidate hydrochloride tablets treatment, reassess each patient's risk of abuse, misuse, and addiction and frequently monitor for signs and symptoms of abuse, misuse, and addiction [see Warnings and Precautions (5.1) and Drug Abuse and Dependence (9.2) ] .
INDICATIONS AND USAGE
Dexmethylphenidate hydrochloride tablets are indicated for the treatment of Attention Deficit Hyperactivity Disorder (ADHD) [see Clinical Studies (14) ] .
DOSAGE AND ADMINISTRATION
• Administer orally twice daily, 4 hours apart with or without food (2 ). • For patients new to methylphenidate: Recommend starting dose of 5 mg once daily (2.5 mg twice daily) (2.2 ). • For patients currently taking methylphenidate: Initiate dexmethylphenidate hydrochloride tablets therapy with half (1/2) the current total daily dose of methylphenidate (2.2 ). • Titrate weekly in increments of 2.5 to 5 mg to a maximum of 20 mg/day (10 mg twice daily) (2.2 ).
Pretreatment Screening
Prior to treating patients with dexmethylphenidate hydrochloride tablets, 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 tablets [see Warnings and Precautions (5.10) ] .
Recommended Dosage
Patients New to Methylphenidate The recommended starting dose of dexmethylphenidate hydrochloride tablets for pediatric patients who are not currently taking racemic methylphenidate, or for patients who are on stimulants other than methylphenidate, is 5 mg daily (2.5 mg twice daily) with or without food.
Patients Currently on Methylphenidate The recommended starting dose of dexmethylphenidate hydrochloride tablets for pediatric patients currently using methylphenidate is half (1/2) the total daily dose of racemic methylphenidate.
Titration Schedule The dose may be titrated weekly in increments of 2.5 to 5 mg to a maximum of 20 mg daily (10 mg twice daily). The dose should be individualized according to the needs and response of the patient.
Administration Instructions
Dexmethylphenidate hydrochloride tablets are administered orally twice daily, at least 4 hours apart.
Dosage Reduction and Discontinuation
If paradoxical aggravation of symptoms or other adverse reactions occur, reduce the dosage, or if necessary, discontinue dexmethylphenidate hydrochloride tablets. If improvement is not observed after appropriate dosage adjustment over a one-month period, the drug should be discontinued.
DOSAGE FORMS AND STRENGTHS
• 5 mg tablets: Yellow, round, uncoated tablet, debossed with "NP045" on one side and "5" on the other side.
• 10 mg tablets: Blue, round, uncoated tablet, debossed with "NP046" on one side and "10" on the other side.
USE IN SPECIFIC POPULATIONS
Pregnancy
Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to ADHD medications, including dexmethylphenidate hydrochloride tablets, during pregnancy. Healthcare providers are encouraged to register patients by calling the National Pregnancy Registry for ADHD medications at 1-866-961-2388 or visiting https://womensmentalhealth.org/adhd-medications/.
Risk Summary Dexmethylphenidate is the d-threo enantiomer of racemic methylphenidate. Published studies and postmarketing reports on methylphenidate use during pregnancy have not identified a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. There may be risks to the fetus associated with the use of CNS stimulants during pregnancy (see Clinical Considerations ). Embryo-fetal development studies in rats showed delayed fetal skeletal ossification at doses up to 5 times the maximum recommended human dose (MRHD) of 20 mg/day given to adults based on plasma levels. A decrease in pup weight in males was observed in a pre- and post-natal development study with oral administration of methylphenidate to rats throughout pregnancy and lactation at doses 5 times the MRHD of 20 mg/day given to adults based on plasma levels. Plasma levels in adults were comparatively similar to plasma levels in adolescents (see Data ).
The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.
Clinical Considerations Fetal/Neonatal Adverse Reactions CNS stimulants, such as dexmethylphenidate hydrochloride tablets, can cause vasoconstriction and thereby decrease placental perfusion. No fetal and/or neonatal adverse reactions have been reported with the use of therapeutic doses of methylphenidate during pregnancy; however, premature delivery and low birth weight infants have been reported in amphetamine-dependent mothers.
Data Animal Data In embryo-fetal development studies conducted in rats and rabbits, dexmethylphenidate was administered orally at doses of up to 20 and 100 mg/kg/day, respectively, during the period of organogenesis. No evidence of malformations was found in either the rat or rabbit study; however, delayed fetal skeletal ossification was observed at the highest dose level in rats. When dexmethylphenidate was administered to rats throughout pregnancy and lactation at doses of up to 20 mg/kg/day, post-weaning body weight gain was decreased in male offspring at the highest dose, but no other effects on postnatal development were observed. At the highest doses tested, plasma levels [area under the curves (AUCs)] of dexmethylphenidate in pregnant rats and rabbits were approximately 5 and 1 times, respectively, those in adults dosed with the MRHD of 20 mg/day.
Racemic methylphenidate has been shown to cause malformations (increased incidence of fetal spina bifida) in rabbits when given in doses of 200 mg/kg/day throughout organogenesis.
Lactation
Risk Summary Dexmethylphenidate is the d-threo enantiomer of racemic methylphenidate. Limited published literature, based on milk sampling from seven mothers' reports that methylphenidate is present in human milk, which resulted in infant doses of 0.16% to 0.7% of the maternal weight-adjusted dosage and a milk/plasma ratio ranging between 1.1 and 2.7. There are no reports of adverse effects on the breastfed infant and no effects on milk production. Long-term neurodevelopmental effects on infants from stimulant exposure are unknown. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for dexmethylphenidate hydrochloride tablets and any potential adverse effects on the breastfed infant from dexmethylphenidate hydrochloride tablets or from the underlying maternal condition. Clinical Considerations Monitor breastfeeding infants for adverse reactions, such as agitation, insomnia, anorexia, and reduced weight gain.
Pediatric Use
The safety and effectiveness of dexmethylphenidate hydrochloride tablets have been established in pediatric patients aged 6 to 17 years in two adequate and well-controlled clinical trials [see Clinical Studies (14) ]. The safety and effectiveness of dexmethylphenidate hydrochloride tablets in pediatric patients aged less than 6 years have not been established. The long-term efficacy of dexmethylphenidate hydrochloride tablets in pediatric patients has not been established. Long Term Suppression of Growth Growth should be monitored during treatment with stimulants, including dexmethylphenidate hydrochloride tablets. Pediatric patients who are not growing or gaining weight as expected may need to have their treatment interrupted [see Warnings and Precautions (5.7) ]. Juvenile Animal Toxicity Data Rats treated with racemic methylphenidate early in the postnatal period through sexual maturation demonstrated a decrease in spontaneous locomotor activity in adulthood. A deficit in acquisition of a specific learning task was observed in females only. The doses at which these findings were observed are at least 6 times the MRHD of 60 mg/day given to children on a mg/m 2 basis. In a study conducted in young rats, racemic methylphenidate was administered orally at doses of up to 100 mg/kg/day for 9 weeks, starting early in the postnatal period (postnatal Day 7) and continuing through sexual maturity (postnatal week 10). When these animals were tested as adults (postnatal Weeks 13 to 14), decreased spontaneous locomotor activity was observed in males and females previously treated with 50 mg/kg/day (approximately 4 times the MRHD of 60 mg of racemic methylphenidate given to children on a mg/m 2 basis) or greater, and a deficit in the acquisition of a specific learning task was seen in females exposed to the highest dose (8 times the MRHD given to children on a mg/m 2 basis). The no effect level for juvenile neurobehavioral development in rats was 5 mg/kg/day (approximately 0.5 times the MRHD given to children on a mg/m 2 basis). The clinical significance of the long-term behavioral effects observed in rats is unknown.
Geriatric Use
Dexmethylphenidate hydrochloride tablets have not been studied in the geriatric population.
CONTRAINDICATIONS
• Hypersensitivity to methylphenidate or other components of dexmethylphenidate hydrochloride tablets. Hypersensitivity reactions, such as angioedema and anaphylactic reactions have been reported in patients treated with methylphenidate [see Adverse Reactions (6.1) ]. • Concomitant treatment with monoamine oxidase inhibitors (MAOIs), or within 14 days following discontinuation of treatment with an MAOI, because of the risk of hypertensive crises [see Drug Interactions (7.1) ].
WARNINGS AND PRECAUTIONS
• Risks to Patients with Serious Cardiac Disease: Avoid use in patients with known structural cardiac abnormalities, cardiomyopathy, serious cardiac arrhythmias, coronary artery disease, or other serious cardiac disease (5.2 ). • Increased Blood Pressure and Heart Rate: Monitor blood pressure and pulse. (5.3 ). • Psychiatric Adverse Reactions: Prior to initiating dexmethylphenidate hydrochloride tablets, screen patients for risk factors for developing a manic episode. If new psychotic or manic symptoms occur, consider discontinuing dexmethylphenidate hydrochloride tablets (5.4 ). • Priapism: If abnormally sustained or frequent and painful erections occur, patients should seek immediate medical attention (5.5 ). • Peripheral Vasculopathy, including Raynaud's Phenomenon: Careful observation for digital changes is necessary during dexmethylphenidate hydrochloride tablets treatment. Further clinical evaluation (e.g., rheumatology referral) may be appropriate for patients who develop signs or symptoms of peripheral vasculopathy (5.6 ). • Long-Term Suppression of Growth in Pediatric Patients: Closely monitor growth (height and weight) in pediatric patients. Pediatric patients not growing or gaining height or weight as expected may need to have their treatment interrupted (5.7 ). • Acute Angle Closure Glaucoma: Dexmethylphenidate hydrochloride tablets -treated patients considered at risk for acute angle closure glaucoma (e.g., patients with significant hyperopia) should be evaluated by an ophthalmologist (5.8 ). • Increased Intraocular Pressure (IOP) and Glaucoma: Prescribe dexmethylphenidate hydrochloride tablets to patients with open-angle glaucoma or abnormally increased IOP only if the benefit of treatment is considered to outweigh the risk. Closely monitor patients with a history of increased IOP or open angle glaucoma (5.9 ). • Motor and Verbal Tics, and Worsening of Tourette's Syndrome: Before initiating dexmethylphenidate hydrochloride tablets, assess the family history and clinically evaluate patients for tics or Tourette's syndrome. Regularly monitor patients for the emergence or worsening of tics or Tourette's syndrome. Discontinue treatment if clinically appropriate (5.10 ).
Abuse, Misuse and Addiction
Dexmethylphenidate hydrochloride tablets have a high potential for abuse and misuse. The use of dexmethylphenidate hydrochloride tablets exposes individuals to the risks of abuse and misuse, which can lead to the development of a substance use disorder, including addiction. Dexmethylphenidate hydrochloride tablets can be diverted for non-medical use into illicit channels or distribution [see Drug Abuse and Dependence (9.2) ]. Misuse and abuse of CNS stimulants, including dexmethylphenidate hydrochloride tablets, can result in overdose and death [see Overdosage (10) ], and this risk is increased with higher doses or unapproved methods of administration, such as snorting or injection.
Before prescribing dexmethylphenidate hydrochloride tablets, assess each patient's risk for abuse, misuse, and addiction. Educate patients and their families about these risks and proper disposal of any unused drug. Advise patients to store dexmethylphenidate hydrochloride tablets in a safe place, preferably locked, and instruct patients to not give dexmethylphenidate hydrochloride tablets to anyone else. Throughout dexmethylphenidate hydrochloride tablets treatment, reassess each patient's risk of abuse, misuse, and addiction and frequently monitor for signs and symptoms of abuse, misuse, and addiction.
Risks to Patients With Serious Cardiac Disease
Sudden death has been reported in patients with structural cardiac abnormalities or other serious cardiac disease who are treated with CNS stimulants at the recommended ADHD dosage.
Avoid dexmethylphenidate hydrochloride tablets use in patients with known structural cardiac abnormalities, cardiomyopathy, serious cardiac arrhythmia, coronary artery disease, or other serious cardiac disease.
Increased Blood Pressure and Heart Rate
CNS stimulants cause an increase in blood pressure (mean increase approximately 2 to 4 mmHg) and heart rate (mean increase approximately 3 to 6 beats per minute). Some patients may have larger increases.
Monitor all dexmethylphenidate hydrochloride tablets-treated patients for hypertension and tachycardia.
Psychiatric Adverse Reactions
Exacerbation of Preexisting Psychosis
CNS stimulants may exacerbate symptoms of behavior disturbance and thought disorder in patients with a preexisting psychotic disorder.
Induction of a Manic Episode in Patients with Bipolar Disorder
CNS stimulants may induce a manic or mixed mood episode in patients. Prior to initiating dexmethylphenidate hydrochloride tablets treatment, screen patients for risk factors for developing a manic episode (e.g., comorbid or history of depressive symptoms or a family history of suicide, bipolar disorder, or depression).
New Psychotic or Manic Symptoms
CNS stimulants, at recommended dosage, may cause psychotic or manic symptoms (e.g., hallucinations, delusional thinking, or mania) in patients without a prior history of psychotic illness or mania. In a pooled analysis of multiple short-term, placebo-controlled studies of CNS stimulants, psychotic or manic symptoms occurred in approximately 0.1% of CNS stimulant-treated patients, compared to 0% of placebo-treated patients. If such symptoms occur, consider discontinuing dexmethylphenidate hydrochloride tablets.
Priapism
Prolonged and painful erections, sometimes requiring surgical intervention, have been reported with methylphenidate use in both adult and pediatric male patients. Although priapism was not reported with methylphenidate initiation, it developed after some time on methylphenidate, often subsequent to an increase in dosage. Priapism also occured during methylphenidate withdrawal (drug holidays or during discontinuation). Dexmethylphenidate hydrochloride tablets-treated patients who develop abnormally sustained or frequent and painful erections should seek immediate medical attention.
Peripheral Vasculopathy, Including Raynaud’s Phenomenon
CNS stimulants, including dexmethylphenidate hydrochloride tablets, used to treat ADHD are associated with peripheral vasculopathy, including Raynaud's phenomenon. Signs and symptoms are usually intermittent and mild; however, sequelae have included digital ulceration and/or soft tissue breakdown. Effects of peripheral vasculopathy, including Raynaud's phenomenon, were observed in post-marketing reports and at the therapeutic dosages of CNS stimulants in all age groups throughout the course of treatment. Signs and symptoms generally improved after dosage reduction or discontinuation of the CNS stimulant.
Careful observation for digital changes is necessary during dexmethylphenidate hydrochloride tablets treatment. Further clinical evaluation (e.g., rheumatology referral) may be appropriate for dexmethylphenidate hydrochloride tablets-treated patients who develop signs or symptoms of peripheral vasculopathy.
Long-Term Suppression of Growth in Pediatric Patients
CNS stimulants have been associated with weight loss and slowing of growth rate in pediatric patients.
Careful follow-up of weight and height in pediatric patients ages 7 to 10 years who were randomized to either methylphenidate or non-medication treatment groups over 14 months, as well as in naturalistic subgroups of newly methylphenidate-treated and non-medication treated patients over 36 months (to the ages of 10 to 13 years), suggests that pediatric patients who received methylphenidate for 7 days per week throughout the year had a temporary slowing in growth rate (on average, a total of about 2 cm less growth in height and 2.7 kg less growth in weight over 3 years), without evidence of growth rebound during this development period.
Closely monitor growth (weight and height) in dexmethylphenidate hydrochloride tablets-treated pediatric patients. Pediatric patients who are not growing or gaining height or weight as expected may need to have their treatment interrupted.
Acute Angle Closure Glaucoma
There have been reports of angle closure glaucoma associated with methylphenidate treatment.
Although the mechanism is not clear, dexmethylphenidate hydrochloride tablets-treated patients considered at risk for acute angle closure glaucoma (e.g., patients with significant hyperopia) should be evaluated by an ophthalmologist.
Increased Intraocular Pressure and Glaucoma
There have been reports of an elevation of intraocular pressure (IOP) associated with methylphenidate treatment [see Adverse Reactions (6.2) ].
Prescribe dexmethylphenidate hydrochloride tablets to patients with open-angle glaucoma or abnormally increased IOP only if the benefit of treatment is considered to outweigh the risk. Closely monitor dexmethylphenidate hydrochloride tablets-treated patients with a history of abnormally increased IOP or open angle glaucoma.
Motor and Verbal Tics, and Worsening of Tourette’s Syndrome
CNS stimulants, including methylphenidate, have been associated with the onset or exacerbation of motor and verbal tics. Worsening of Tourette's syndrome has also been reported [see Adverse Reactions (6.2) ].
Before initiating dexmethylphenidate hydrochloride tablets, assess the family history and clinically evaluate patients for tics or Tourette's syndrome. Regularly monitor dexmethylphenidate hydrochloride tablets-treated patients for the emergence or worsening of tics or Tourette's syndrome, and discontinue treatment if clinically appropriate.
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 tablets [see Contraindications (4) ] • Hypertensive crisis with Concomitant Use of Monoamine Oxidase Inhibitors [see Contraindications (4) , Drug Interactions (7.1) ] • Risk 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) ]
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 Tablets in Pediatric Patients with ADHD
The safety data in this section is based on data related to dexmethylphenidate hydrochloride tablets exposure during the premarketing development program in a total of 696 participants in clinical trials (684 patients, 12 healthy adult subjects). These participants received dexmethylphenidate hydrochloride tablets 5, 10, or 20 mg/day. The 684 ADHD patients (ages 6 to 17 years) were evaluated in 2 controlled clinical studies, 2 clinical pharmacology studies, and 2 open-label long-term safety studies.
Most Common Adverse Reactions (incidence of greater than or equal to 5% and at least twice placebo): abdominal pain, fever, anorexia, and nausea
Adverse Reactions Leading to Discontinuation: Overall, 50 of 684 (7.3%) pediatric patients treated with dexmethylphenidate hydrochloride 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 two, placebo-controlled, parallel group studies in pediatric patients with ADHD taking dexmethylphenidate hydrochloride tablets doses of 5, 10, and 20 mg/day. The table includes only those reactions that occurred in patients treated with dexmethylphenidate hydrochloride tablets for which the incidence was at least 5% and twice the incidence among placebo-treated patients. Table 1 : Common Adverse Reactions in Pediatric Patients (6 to 17 years of age) With ADHD
| System organ class | Adverse reactions | Dexmethylphenidate hydrochloride tablets (N = 79) | Placebo (N = 82) |
| Body as a whole | Abdominal Pain | 15 % | 6 % |
| Fever | 5 % | 1 % | |
| Digestive system | Anorexia | 6 % | 1 % |
| Nausea | 9 % | 1 % |
Abbreviation: ADHD, attention deficit hyperactivity disorder.
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, such as angioedema, anaphylactic reactions
Adverse Reactions Reported with All Ritalin and Dexmethylphenidate Hydrochloride Tablets Formulations The following adverse reactions associated with the use of all Ritalin and dexmethylphenidate hydrochloride tablets 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 choreoatheetoid 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-Containing Products The list below shows adverse reactions not listed with Ritalin and dexmethylphenidate hydrochloride tablets 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 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 Urogenital Disorders: priapism
Antihypertensive Drugs : Monitor blood pressure. Adjust dosage of antihypertensive drug as needed (7.1 ).
Clinically Important Drug Interactions With Dexmethylphenidate Hydrochloride Tablets
Table 2 presents clinically important drug interactions with dexmethylphenidate hydrochloride tablets.
Table 2 : Clinically Important Drug Interactions with Dexmethylphenidate Hydrochloride Tablets
| Monoamine Oxidase Inhibitors (MAOIs) | |
| Clinical Impact | Concomitant use of MAOIs and CNS stimulants, including dexmethylphenidate hydrochloride tablets, can cause hypertensive crisis. Potential outcomes include death, stroke, myocardial infarction, aortic dissection, ophthalmological complications, eclampsia, pulmonary edema, and renal failure [see Contraindications (4) ]. |
| Intervention | Concomitant use of dexmethylphenidate hydrochloride tablets with MAOIs or within 14 days after discontinuing MAOI treatment is contraindicated. |
| Antihypertensive Drugs | |
| Clinical Impact | Dexmethylphenidate hydrochloride tablets may decrease the effectiveness of drugs used to treat hypertension [see Warnings and Precautions (5.3) ]. |
| Intervention | Adjust the dosage of the antihypertensive drug as needed. |
| Halogenated Anesthetics | |
| Clinical Impact | Concomitant use of halogenated anesthetics and dexmethylphenidate hydrochloride tablets may increase the risk of sudden blood pressure and heart rate increase during surgery. |
| Intervention | Monitor blood pressure and avoid use of dexmethylphenidate hydrochloride tablets in patients being treated with anesthetics on the day of surgery. |
| Risperidone | |
| Clinical Impact | Combined use of methylphenidate with risperidone when there is a change, whether an increase or decrease, in dosage of either or both medications, may increase the risk of extrapyramidal symptoms (EPS) |
| Intervention | Monitor for signs of EPS |
DESCRIPTION
Dexmethylphenidate hydrochloride tablets contain dexmethylphenidate hydrochloride, a CNS stimulant. Dexmethylphenidate hydrochloride is the d-threo enantiomer of racemic methylphenidate hydrochloride. Dexmethylphenidate hydrochloride tablets are available as 5 mg and 10 mg strength tablets for oral administration. Chemically, dexmethylphenidate hydrochloride is methyl α-phenyl-2-piperidineacetate hydrochloride, (R,R')-(+)-. Its molecular formula is C 14 H 19 NO 2 •HCl. Its structural formula is:
Note: • = asymmetric carbon centers Dexmethylphenidate hydrochloride is a white crystalline powder. Its solutions are acid to litmus. It is soluble in water and in methanol, very slightly soluble in acetone. Its molecular weight is 269.77 g/mol.
Inactive ingredients: lactose monohydrate, silicified microcrystalline cellulose, sodium lauryl sulfate, magnesium stearate, and D&C Yellow #10 aluminum lake (5 mg tablets), FD&C Blue #2 aluminum lake (10 mg tablets).
CLINICAL PHARMACOLOGY
Mechanism of Action
Dexmethylphenidate hydrochloride is a CNS stimulant. The mode of therapeutic action in ADHD is not known.
Pharmacodynamics
Pharmacodynamics Dexmethylphenidate is the more pharmacologically active d-enantiomer of racemic methylphenidate. Methylphenidate blocks the reuptake of norepinephrine and dopamine into the presynaptic neuron and increase the release of these monoamines into the extraneuronal space. Cardiac Electrophysiology A formal QT study has not been conducted in patients taking dexmethylphenidate hydrochloride tablets; however, a large QT effect is not expected. At the recommended maximum total daily dosage of 40 mg, Focalin XR (dexmethylphenidate) extended-release capsule does not prolong the QTc interval to any clinically relevant extent.
Pharmacokinetics
Absorption Dexmethylphenidate hydrochloride is readily absorbed following oral administration of dexmethylphenidate hydrochloride tablets. In patients with ADHD, plasma dexmethylphenidate concentrations increase rapidly, reaching a maximum in the fasted state at about 1 to 1.5 hours postdose. No differences in the pharmacokinetics of dexmethylphenidate hydrochloride tablets were noted following single and repeated twice daily dosing, thus indicating no significant drug accumulation in children with ADHD. After single dose administration of dexmethylphenidate hydrochloride tablets to pediatric patients, dexmethylphenidate exposure (C max and AUC 0-inf ) showed dose-proportional increase in the range of 2.5 mg to 10 mg. Comparable plasma dexmethylphenidate levels were achieved following single dl-threo -methylphenidate HCl doses given as capsules in twice the total mg amount (equimolar with respect to dexmethylphenidate hydrochloride tablets). 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%. Effect of Food High fat breakfast did not significantly affect C max or AUC 0-inf of dexmethylphenidate when two 10 mg dexmethylphenidate hydrochloride tablets were administered, but delayed T max from 1.5 hours post dose to 2.9 hours post dose. 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 declined exponentially following oral administration of dexmethylphenidate hydrochloride tablets. Intravenous dexmethylphenidate was eliminated with a mean clearance of 0.40 + 0.12 L/hr/kg. The mean terminal elimination half-life of dexmethylphenidate was approximately 2.2 hours. 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 little or 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 Special Populations Male and Female Patients Pharmacokinetic parameters were similar for boys and girls (mean age 10 years). In a single dose study conducted in adults, the mean dexmethylphenidate AUC 0-inf values (adjusted for body weight) following single two 10 mg doses of dexmethylphenidate hydrochloride tablets were 25% to 35% higher in adult female volunteers (n = 6) compared to male volunteers (n = 9). Both T max and t 1/2 were comparable for males and females. Racial or Ethnic Groups There is insufficient experience with the use of dexmethylphenidate hydrochloride tablets to detect ethnic variations in pharmacokinetics. Pediatric Patients The pharmacokinetics of dexmethylphenidate after dexmethylphenidate hydrochloride tablets administration have not been studied in children less than 6 years of age. When single doses of dexmethylphenidate hydrochloride tablets were given to children between the ages of 6 to 12 years and healthy adult volunteers, C max of dexmethylphenidate was similar, however, pediatric patients showed somewhat lower AUCs compared to the adults. Patients with Renal Impairment There is no experience with the use of dexmethylphenidate hydrochloride tablets in patients with renal impairment. Since renal clearance is not an important route of methylphenidate clearance, renal impairment is expected to have little effect on the pharmacokinetics of dexmethylphenidate hydrochloride tablets. Patients with Hepatic Impairment There is no experience with the use of dexmethylphenidate hydrochloride tablets 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.
NONCLINICAL TOXICOLOGY
Carcinogenesis, Mutagenesis, and Impairment of Fertility
Carcinogenesis Lifetime carcinogenicity studies have not been carried out with dexmethylphenidate. In a lifetime carcinogenicity study carried out in B6C3F1 mice, racemic methylphenidate caused an increase in hepatocellular adenomas, and in males only, an increase in hepatoblastomas was seen at a daily dose of approximately 60 mg/kg/day. This dose is approximately 2 times the MRHD of 60 mg/day of racemic methylphenidate given to children on a mg/m 2 basis. Hepatoblastoma is a relatively rare rodent malignant tumor type. There was no increase in total malignant hepatic tumors. The mouse strain used is sensitive to the development of hepatic tumors and the significance of these results to humans is unknown. Racemic methylphenidate did not cause any increase in tumors in a lifetime carcinogenicity study carried out in F344 rats; the highest dose used was approximately 45 mg/kg/day, which is approximately 4 times the MRHD (children) of 60 mg/day of racemic methylphenidate on a mg/m 2 basis. In a 24-week carcinogenicity study with racemic methylphenidate in the transgenic mouse strain p53+/-, which is sensitive to genotoxic carcinogens, there was no evidence of carcinogenicity. Male and female mice were fed diets containing the same concentrations as in the lifetime carcinogenicity study; the high-dose group was exposed to 60-74 mg/kg/day of racemic methylphenidate. Mutagenesis Dexmethylphenidate was not mutagenic in the in vitro Ames reverse mutation assay, in the in vitro mouse lymphoma cell forward mutation assay, or in the in vivo mouse bone marrow micronucleus test. In an in vitro assay using cultured Chinese Hamster Ovary cells treated with racemic methylphenidate, sister chromatid exchanges and chromosome aberrations were increased, indicative of a weak clastogenic response. Impairment of Fertility No human data on the effect of methylphenidate on fertility are available. Fertility studies have not been conducted with dexmethylphenidate. Racemic methylphenidate did not impair fertility in male or female mice that were fed diets containing the drug in an 18-week continuous breeding study. The study was conducted at doses of up to 160 mg/kg/day, approximately 10 times the MRHD of 60 mg/day of racemic methylphenidate given adolescents on a mg/m 2 basis.
CLINICAL STUDIES
The efficacy of dexmethylphenidate hydrochloride tablets for the treatment of ADHD was established in two double-blind, parallel-group, placebo-controlled trials in untreated or previously treated patients (ages 6 to 17 years old) who met The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria for ADHD inattentive, hyperactive-impulsive, or combined inattentive/hyperactive-impulsive subtypes. The sample was predominantly younger (ages 6 to 12 years); thus, the findings are most pertinent to this age group. In Study 1, patients were randomized to receive either dexmethylphenidate hydrochloride tablets (5, 10, or 20 mg/day total dose), racemic methylphenidate HCl (10, 20, or 40 mg/day total dose), or placebo in a multicenter, 4-week, parallel group study in 132 pediatric patients. Patients received study medication twice daily separated by a 3.5 to 5.5 hours interval. Treatment was initiated with the lowest dose, and doses could be doubled at weekly intervals, depending on clinical response and tolerability, up to the maximum dose. The primary outcome was change from baseline to week 4 of the average score (an average of 2 ratings during the week) of the teacher's version of the Swanson, Nolan and Pelham (SNAP)-ADHD Rating Scale. This 18 item scale measures ADHD symptoms of inattention and hyperactivity/impulsivity, rated on a scale of 0 (Not at All) to 3 (Very Much). Patients treated with dexmethylphenidate hydrochloride tablets showed a statistically significant improvement in symptom scores from baseline over patients who received placebo (Table 3). Table 3 : Summary of Efficacy Results From ADHD Acute-Phase Study in Pediatric Patients (6 – 17 years) (Study 1)
| Study number | Treatment group | Primary efficacy measure: teacher SNAP-ADHD total score a | |
| Mean baseline score (SD) | Mean change from baseline Week 4 score (SD) | ||
| Study 1 | Dexmethylphenidate hydrochloride tablets 5-20 mg/day b (n=44) | 1.4 (0.7) (n=42) | -0.7 (0.7) (n=42) |
| Placebo (n=42) | 1.6 (0.7) (n=41) | -0.2 (0.7) (n=39) | |
Abbreviations: ADHD, attention deficit hyperactivity disorder; SD, standard deviation; SNAP; swanson, Nolan and Pelham; n, number of patients available at the assessment time point. a Average of two ratings. b Statistically significantly different from placebo. Study 2 was a multicenter, placebo-controlled, double-blind, 2-week treatment withdrawal study in 75 children (ages 6 to 12 years) who were responders during a 6-week, open-label initial treatment period. Children took study medication twice a day separated by a 3.5 to 5.5 hour interval. The primary outcome was proportion of treatment failures at the end of the 2-week withdrawal phase, where treatment failure was defined as a rating of 6 (much worse) or 7 (very much worse) on the Investigator Clinical Global Impression - Improvement (CGI-I). Patients continued on dexmethylphenidate hydrochloride tablets showed a statistically significant lower rate of failure over patients who received placebo (Table 4). Table 4 : Summary of Efficacy Results From ADHD Randomized Withdrawal Study in Pediatric Patients (6 – 17 years) (Study 2)
| Study number | Treatment group | Primary efficacy measure: proportion of treatment failure a | |
| Number of treatment failures/ Number of randomized patients | Percentage | ||
| Study 2 | Dexmethylphenidate hydrochloride tablets 5-20 mg/day b | 6/35 | 17.1% |
| Placebo | 25/40 | 62.5% | |
| Abbreviation: ADHD, attention deficit hyperactivity disorder. a One patient did not have the value at visit 10 and hence not included in this analysis. b Statistically significantly different from placebo. | |||
HOW SUPPLIED/STORAGE AND HANDLING
Dexmethylphenidate hydrochloride tablets are available as follows: • 5 mg tablets (NDC 75834-327-01) yellow, round, uncoated, debossed with "NP045" on one side and "5" on the other side, supplied in bottles of 100 • 10 mg tablets (NDC 75834-328-01) blue, round, uncoated, debossed with "NP046" on one side and "10" on the other side, supplied in bottles of 100 Store at 20°C to 25°C (68°F to 77°F); excursions permitted between 15°C and 30°C (59°F and 86°F) [see USP Controlled Room Temperature]. Protect from light and moisture. Dispense in tight, light-resistant container (USP).
Mechanism of Action
Dexmethylphenidate hydrochloride is a CNS stimulant. The mode of therapeutic action in ADHD is not known.
