methylphenidate hydrochloride CD (methylphenidate hydrochloride 40 mg) Dailymed

Once Daily

Rx only

Description

Methylphenidate HCl Extended-Release Capsules CD is a central nervous system (CNS) stimulant. The extended-release capsules comprise both immediate-release (IR) and extended-release (ER) beads such that 30% of the dose is provided by the IR component and 70% of the dose is provided by the ER component. Methylphenidate HCl Extended-Release Capsules CD is available in six capsule strengths containing 10 mg (3 mg IR; 7 mg ER), 20 mg (6 mg IR; 14 mg ER), 30 mg (9 mg IR; 21 mg ER), 40 mg (12 mg IR; 28 mg ER), 50 mg (15 mg IR; 35 mg ER), or 60 mg (18 mg IR; 42 mg ER) of methylphenidate hydrochloride for oral administration.

Chemically, methylphenidate HCl is d,l (racemic)-threo-methyl α-phenyl-2-piperidineacetate hydrochloride. Its empirical formula is C₁₄H₁₉NO₂•HCl. Its structural formula is:



Methylphenidate HCl USP is a white, odorless, crystalline powder. Its solutions are acid to litmus. It is freely soluble in water and in methanol, soluble in alcohol, and slightly soluble in chloroform and in acetone. Its molecular weight is 269.77.

Methylphenidate HCl Extended-Release Capsules CD also contains the following inert ingredients: Sugar spheres, povidone, hydroxypropylmethylcellulose and polyethylene glycol, ethylcellulose aqueous dispersion, dibutyl sebacate, gelatin, and titanium dioxide.

The individual capsules contain the following color agents:

10 mg capsules: FD&C Blue No. 2, FDA/E172 Yellow Iron Oxide20 mg capsules: FD&C Blue No. 230 mg capsules: FD&C Blue No. 2, FDA/E172 Red Iron Oxide40 mg capsules: FDA/E172 Yellow Iron Oxide50 mg capsules: FD&C Blue No. 2, FDA/E172 Red Iron Oxide

Clinical Pharmacology

Pharmacodynamics

Methylphenidate HCl is a central nervous system (CNS) stimulant. The mode of therapeutic action in Attention Deficit Hyperactivity Disorder (ADHD) is not known. Methylphenidate is thought to block the reuptake of norepinephrine and dopamine into the presynaptic neuron and increase the release of these monoamines into the extraneuronal space. Methylphenidate is a racemic mixture comprised of the d- and l-threo enantiomers. The d-threo enantiomer is more pharmacologically active than the l-threo enantiomer.

Pharmacokinetics

The pharmacokinetics of the Methylphenidate HCl Extended-Release Capsules CD methylphenidate hydrochloride formulation have been studied in healthy adult volunteers and in children with Attention Deficit Hyperactivity Disorder (ADHD).

Absorption And Distribution

Methylphenidate is readily absorbed. Methylphenidate HCl Extended-Release Capsules CD has a plasma/time concentration profile showing two phases of drug release with a sharp, initial slope similar to a methylphenidate immediate-release tablet, and a second rising portion approximately three hours later, followed by a gradual decline. (See Figure 1 below.)

Comparison Of Immediate Release (IR) And Methylphenidate HCl Extended-Release Capsules CD Formulations After Repeated Doses Of Methylphenidate HCl In Children With ADHD

Methylphenidate HCl Extended-Release Capsules CD was administered as repeated once-daily doses of 20 mg or 40 mg to children aged 7-12 years with ADHD for one week. After a dose of 20 mg, the mean (±SD) early C_max was 8.6 (±2.2) ng/mL, the later C_max was 10.9 (±3.9)25-30% of the subjects had only one observed peak (C_max) concentration of methylphenidate. ng/mL and AUC_0-9h was 63.0 (±16.8) ng∙h/mL. The corresponding values after a 40 mg dose were 16.8 (±5.1) ng/mL, 15.1 (±5.8) ng/mL and 120 (±39.6) ng∙h/mL, respectively. The early peak concentrations (median) were reached about 1.5 hours after dose intake, and the second peak concentrations (median) were reached about 4.5 hours after dose intake. The means for C_max and AUC following a dose of 20 mg were slightly lower than those seen with 10 mg of the immediate-release formulation, dosed at 0 and 4 hours.

FIGURE 1 Comparison of Immediate Release (IR) and Methylphenidate HCl Extended-Release Capsules CD Formulations After Repeated Doses of Methylphenidate HCl in Children with ADHD

Dose Proportionality

Following single oral doses of 10-60 mg methylphenidate free base as a solution given to ten healthy male volunteers, C_max and AUC increased proportionally with increasing doses. After the 60 mg dose, t_max was reached 1.5 hours post-dose, with a mean C_max of 31.8 ng/mL (range 24.7-40.9 ng/mL).

Following one week of repeated once-daily doses of 20 mg or 40 mg Methylphenidate HCl Extended-Release Capsules CD to children aged 7-12 years with ADHD, C_max and AUC were proportional to the administered dose.

Food Effects

In a study in adult volunteers to investigate the effects of a high-fat meal on the bioavailability of a dose of 40 mg, the presence of food delayed the early peak by approximately 1 hour (range -2 to 5 hours delay). The plasma levels rose rapidly following the food-induced delay in absorption. Overall, a high-fat meal increased the C_max of Methylphenidate HCl Extended-Release Capsules CD by about 30% and AUC by about 17%, on average (see DOSAGE AND ADMINISTRATION).

After a single dose, the bioavailability (C_max and AUC) of methylphenidate in 26 healthy adults was unaffected by sprinkling the capsule contents on applesauce as compared to the intact capsule. This finding demonstrates that a 20 mg Methylphenidate HCl Extended-Release Capsules CD capsule, when opened and sprinkled on one tablespoon of applesauce, is bioequivalent to the intact capsule.

Metabolism And Excretion

In humans, methylphenidate is metabolized primarily via deesterification to alpha-phenyl-piperidine acetic acid (ritalinic acid). The metabolite has little or no pharmacologic activity.

In vitro studies showed that methylphenidate was not metabolized by cytochrome P450 isoenzymes, and did not inhibit cytochrome P450 isoenzymes at clinically observed plasma drug concentrations.

The mean terminal half-life (t_½) of methylphenidate following administration of Methylphenidate HCl Extended-Release Capsules CD (t_½=6.8h) is longer than the mean terminal (t_½) following administration of methylphenidate hydrochloride immediate-release tablets (t_½=2.9h) and methylphenidate hydrochloride sustained-release tablets (t_½=3.4h) in healthy adult volunteers. This suggests that the elimination process observed for Methylphenidate HCl Extended-Release Capsules CD is controlled by the release rate of methylphenidate from the extended-release formulation, and that the drug absorption is the rate-limiting process.

Alcohol Effect

An in vitro study was conducted to explore the effect of alcohol on the release characteristics of methylphenidate from the Methylphenidate HCl Extended-Release Capsules CD 60 mg capsule dosage form. At an alcohol concentration of 40% there was an increase in the release rate of methylphenidate in the first hour, resulting in 84% of the methylphenidate being released. The results with the 60 mg capsule are considered to be representative of the other available capsule strengths. Patients should be advised to avoid alcohol while taking Methylphenidate HCl Extended-Release Capsules CD.

Special Populations

Gender

The pharmacokinetics of methylphenidate after a single dose of Methylphenidate HCl Extended-Release Capsules CD were similar between adult men and women.

Race

The influence of race on the pharmacokinetics of methylphenidate after Methylphenidate HCl Extended-Release Capsules CD administration has not been studied.

Age

The pharmacokinetics of methylphenidate after Methylphenidate HCl Extended-Release Capsules CD administration have not been studied in children less than 6 years of age.

Renal Insufficiency

There is no experience with the use of Methylphenidate HCl Extended-Release Capsules CD in patients with renal insufficiency. After oral administration of radiolabeled methylphenidate in humans, methylphenidate was extensively metabolized and approximately 80% of the radioactivity was excreted in the urine in the form of ritalinic acid. Since renal clearance is not an important route of methylphenidate clearance, renal insufficiency is expected to have little effect on the pharmacokinetics of Methylphenidate HCl Extended-Release Capsules CD.

Hepatic Insufficiency

There is no experience with the use of Methylphenidate HCl Extended-Release Capsules CD in patients with hepatic insufficiency.

Clinical Studies

Methylphenidate HCl Extended-Release Capsules CD was evaluated in a double-blind, parallel-group, placebo-controlled trial in which 321 untreated or previously treated pediatric patients with a DSM-IV diagnosis of Attention Deficit Hyperactivity Disorder (ADHD), 6 to 15 years of age, received a single morning dose for up to 3 weeks. Patients were required to have the combined or predominantly hyperactive-impulsive subtype of ADHD; patients with the predominantly inattentive subtype were excluded. Patients randomized to the Methylphenidate HCl Extended-Release Capsules CD group received 20 mg daily for the first week. Their dosage could be increased weekly to a maximum of 60 mg by the third week, depending on individual response to treatment.

The patient's regular school teacher completed the teachers' version of the Conners' Global Index Scale (TCGIS), a scale for assessing ADHD symptoms, in the morning and again in the afternoon on three alternate days of each treatment week. The change from baseline of the overall average (i.e., an average of morning and afternoon scores over 3 days) of the total TCGIS scores during the last week of treatment was analyzed as the primary efficacy parameter. Patients treated with Methylphenidate HCl Extended-Release Capsules CD showed a statistically significant improvement in symptom scores from baseline over patients who received placebo. (See Figure 2.) Separate analyses of TCGIS scores in the morning and afternoon revealed superiority in improvement with Methylphenidate HCl Extended-Release Capsules CD over placebo during both time periods. (See Figure 3.) This demonstrates that a single morning dose of Methylphenidate HCl Extended-Release Capsules CD exerts a treatment effect in both the morning and the afternoon.

FIGURE 2 Least Squares Mean Change from Baseline in TCGIS Scores FIGURES 2 & 3: Last observation carried forward analysis at week 3. Error bars represent the standard of error of the mean.

FIGURE 3 Least Squares Mean Change from Baseline in TCGIS Scores, Morning/Afternoon Groups

Indication And Usage

Attention Deficit Hyperactivity Disorder (ADHD)

Methylphenidate HCl Extended-Release Capsules CD are indicated for the treatment of Attention Deficit Hyperactivity Disorder (ADHD).

The efficacy of Methylphenidate HCl Extended-Release Capsules CD in the treatment of ADHD was established in one controlled trial of children aged 6 to 15 who met DSM-IV criteria for ADHD (see CLINICAL PHARMACOLOGY).

A diagnosis of Attention Deficit Hyperactivity Disorder (ADHD; DSM-IV) implies the presence of hyperactive-impulsive or inattentive symptoms that caused impairment and were present before age 7 years. The symptoms must cause clinically significant impairment, e.g., in social, academic, or occupational functioning, and be present in two or more settings, e.g., school (or work) and at home. The symptoms must not be better accounted for by another mental disorder. For the Inattentive Type, at least six of the following symptoms must have persisted for at least 6 months: lack of attention to details/careless mistakes; lack of sustained attention; poor ulener; failure to follow through on tasks; poor organization; avoids tasks requiring sustained mental effort; loses things; easily distracted; forgetful. For the Hyperactive-Impulsive Type, at least six of the following symptoms must have persisted for at least 6 months: fidgeting/squirming; leaving seat; inappropriate running/climbing; difficulty with quiet activities; "on the go;" excessive talking; blurting answers; can't wait turn; intrusive. The Combined Types requires both inattentive and hyperactive-impulsive criteria to be met.

Special Diagnostic Considerations

Specific etiology of this syndrome is unknown, and there is no single diagnostic test. Adequate diagnosis requires the use not only of medical but of special psychological, educational, and social resources. Learning may or may not be impaired. The diagnosis must be based upon a complete history and evaluation of the child and not solely on the presence of the required number of DSM-IV characteristics.

Need For Comprehensive Treatment Program

Methylphenidate HCl Extended-Release Capsules CD is indicated as an integral part of a total treatment program for ADHD that may include other measures (psychological, educational, social) for patients with this syndrome. Drug treatment may not be indicated for all children with this syndrome. Stimulants are not intended for use in the child who exhibits symptoms secondary to environmental factors and/or other primary psychiatric disorders, including psychosis. Appropriate educational placement is essential and psychosocial intervention is often helpful. When remedial measures alone are insufficient, the decision to prescribe stimulant medication will depend upon the physician's assessment of the chronicity and severity of the child's symptoms.

Long-Term Use

The effectiveness of Methylphenidate HCl Extended-Release Capsules CD for long-term use, i.e., for more than 3 weeks, has not been systematically evaluated in controlled trials. Therefore, the physician who elects to use Methylphenidate HCl Extended-Release Capsules CD for extended periods should periodically re-evaluate the long-term usefulness of the drug for the individual patient (see DOSAGE AND ADMINISTRATION).

Contraindications

Agitation

Methylphenidate HCl Extended-Release Capsules CD is contraindicated in patients with marked anxiety, tension and agitation, since the drug may aggravate these symptoms.

Hypersensitivity To Methylphenidate Or Other Excipients

Methylphenidate HCl Extended-Release Capsules CD is contraindicated in patients known to be hypersensitive to methylphenidate or other components of the product.

Methylphenidate HCl Extended-Release Capsules CD contains sucrose. Therefore, patients with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption, or sucrase-isomaltase insufficiency should not take this medicine.

Glaucoma

Methylphenidate HCl Extended-Release Capsules CD is contraindicated in patients with glaucoma.

Tics

Methylphenidate HCl Extended-Release Capsules CD is contraindicated in patients with motor tics or with a family history or diagnosis of Tourette's syndrome (see ADVERSE REACTIONS).

Monoamine Oxidase Inhibitors

Methylphenidate HCl Extended-Release Capsules CD is contraindicated during treatment with monoamine oxidase inhibitors, and also within a minimum of 14 days following discontinuation of a monoamine oxidase inhibitor (hypertensive crises may result).

Hypertension And Other Cardiovascular Conditions

Methylphenidate HCl Extended-Release Capsules CD is contraindicated in patients with severe hypertension, angina pectoris, cardiac arrhythmias, heart failure, recent myocardial infarction, hyperthyroidism or thyrotoxicosis (see WARNINGS).

Halogenated Anesthetics

There is a risk of sudden blood pressure increase during surgery. If surgery is planned, Methylphenidate HCl Extended-Release Capsules CD should not be taken on the day of the surgery.

Warnings

Serious Cardiovascular Events

Sudden Death And Pre-existing Structural Cardiac Abnormalities Or Other Serious Heart Problems

Children And Adolescents

Sudden death has been reported in association with CNS stimulant treatment at usual doses in children and adolescents with structural cardiac abnormalities or other serious heart problems. Although some serious heart problems alone carry an increased risk of sudden death, stimulant products generally should not be used in children or adolescents with known serious structural cardiac abnormalities, cardiomyopathy, serious heart rhythm abnormalities, or other serious cardiac problems that may place them at increased vulnerability to the sympathomimetic effects of a stimulant drug (see CONTRAINDICATIONS).

Adults

Sudden deaths, stroke, and myocardial infarction have been reported in adults taking stimulant drugs at usual doses for ADHD. Although the role of stimulants in these adult cases is also unknown, adults have a greater likelihood than children of having serious structural cardiac abnormalities, cardiomyopathy, serious heart rhythm abnormalities, coronary artery disease, or other serious cardiac problems. Adults with such abnormalities should also generally not be treated with stimulant drugs (see CONTRAINDICATIONS).

Hypertension And Other Cardiovascular Conditions

Stimulant medications cause a modest increase in average blood pressure (about 2-4 mmHg) and average heart rate (about 3-6 bpm), and individuals may have larger increases. While the mean changes alone would not be expected to have short-term consequences, all patients should be monitored for larger changes in heart rate and blood pressure. Caution is indicated in treating patients whose underlying medical conditions might be compromised by increases in blood pressure or heart rate, e.g., those with pre-existing hypertension, heart failure, recent myocardial infarction, or ventricular arrhythmia (see CONTRAINDICATIONS).

Assessing Cardiovascular Status In Patients Being Treated With Stimulant Medications

Children, adolescents, or adults who are being considered for treatment with stimulant medications should have a careful history (including assessment for a family history of sudden death or ventricular arrhythmia) and physical exam to assess for the presence of cardiac disease, and should receive further cardiac evaluation if findings suggest such disease (e.g., electrocardiogram and echocardiogram). Patients who develop symptoms such as exertional chest pain, unexplained syncope, or other symptoms suggestive of cardiac disease during stimulant treatment should undergo a prompt cardiac evaluation.

Psychiatric Adverse Events

Pre-Existing Psychosis

Administration of stimulants may exacerbate symptoms of behavior disturbance and thought disorder in patients with a pre-existing psychotic disorder.

Bipolar Illness

Particular care should be taken in using stimulants to treat ADHD in patients with comorbid bipolar disorder because of concern for possible induction of a mixed/manic episode in such patients. Prior to initiating treatment with a stimulant, patients with comorbid depressive symptoms should be adequately screened to determine if they are at risk for bipolar disorder; such screening should include a detailed psychiatric history, including a family history of suicide, bipolar disorder, and depression.

Emergence Of New Psychotic Or Manic Symptoms

Treatment emergent psychotic or manic symptoms, e.g., hallucinations, delusional thinking, or mania in children and adolescents without prior history of psychotic illness or mania can be caused by stimulants at usual doses. If such symptoms occur, consideration should be given to a possible causal role of the stimulant, and discontinuation of treatment may be appropriate. In a pooled analysis of multiple short-term, placebo-controlled studies, such symptoms occurred in about 0.1% (4 patients with events out of 3482 exposed to methylphenidate or amphetamine for several weeks at usual doses) of stimulant-treated patients compared to 0 in placebo-treated patients.

Aggression

Aggressive behavior or hostility is often observed in children and adolescents with ADHD, and has been reported in clinical trials and the postmarketing experience of some medications indicated for the treatment of ADHD. Although there is no systematic evidence that stimulants cause aggressive behavior or hostility, patients beginning treatment for ADHD should be monitored for the appearance of or worsening of aggressive behavior or hostility.

Long-Term Suppression Of Growth

Careful follow-up of weight and height in children ages 7 to 10 years who were randomized to either methylphenidate or non-medication treatment groups over 14 months, as well as in naturaulic subgroups of newly methylphenidate-treated and non-medication treated children over 36 months (to the ages of 10 to 13 years), suggests that consistently medicated children (i.e., treatment for 7 days per week throughout the year) have 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 period of development. Published data are inadequate to determine whether chronic use of amphetamines may cause a similar suppression of growth, however, it is anticipated that they likely have this effect as well. Therefore, growth should be monitored during treatment with stimulants, and patients who are not growing or gaining height or weight as expected may need to have their treatment interrupted.

Seizures

There is some clinical evidence that stimulants may lower the convulsive threshold in patients with prior history of seizures, in patients with prior EEG abnormalities in absence of seizures, and, very rarely, in patients without a history of seizures and no prior EEG evidence of seizures. In the presence of seizures, the drug should be discontinued.

Priapism

Prolonged and painful erections, sometimes requiring surgical intervention, have been reported with methylphenidate products in both pediatric and adult patients. Priapism was not reported with drug initiation but developed after some time on the drug, often subsequent to an increase in dose. Priapism has also appeared during a period of drug withdrawal (drug holidays or discontinuation). Patients who develop abnormally sustained or frequent and painful erections should seek immediate medical attention.

Peripheral Vasculopathy, including Raynaud's phenomenon

Stimulants, including Methylphenidate HCl Extended-Release Capsules CD, used to treat ADHD are associated with peripheral vasculopathy, including Raynaud's phenomenon. Signs and symptoms are usually intermittent and mild; however, very rare sequelae include digital ulceration and/or soft tissue breakdown. Effects of peripheral vasculopathy, including Raynaud's phenomenon, were observed in post-marketing reports at different times and at therapeutic doses in all age groups throughout the course of treatment. Signs and symptoms generally improve after reduction in dose or discontinuation of drug. Careful observation for digital changes is necessary during treatment with ADHD stimulants. Further clinical evaluation (e.g., rheumatology referral) may be appropriate for certain patients.

Visual Disturbance

Difficulties with accommodation and blurring of vision have been reported with stimulant treatment.

Use In Children Under Six Years Of Age

Methylphenidate HCl Extended-Release Capsules CD should not be used in children under six years, since safety and efficacy in this age group have not been established.

Drug Dependence

Methylphenidate HCl Extended-Release Capsules CD should be given cautiously to patients with a history of drug dependence or alcoholism. Chronic abusive use can lead to marked tolerance and psychological dependence with varying degrees of abnormal behavior. Frank psychotic episodes can occur, especially with parenteral abuse. Careful supervision is required during withdrawal from abusive use since severe depression may occur. Withdrawal following chronic therapeutic use may unmask symptoms of the underlying disorder that may require follow-up.

Precautions

Hematologic Monitoring

Periodic CBC, differential, and platelet counts are advised during prolonged therapy.

Drug Testing

Methylphenidate HCl Extended-Release Capsules CD contains methylphenidate which may result in a positive result during drug testing.

Information For Patients

Patients should be instructed to take one dose in the morning before breakfast. The patients should be instructed that the capsule may be swallowed whole, or alternatively, the capsule may be opened and the capsule contents sprinkled onto a small amount (tablespoon) of applesauce and given immediately, and not stored for future use. The capsules and the capsule contents must not be crushed or chewed.

Patients should be advised to avoid alcohol while taking Methylphenidate HCl Extended-Release Capsules CD. Consumption of alcohol while taking Methylphenidate HCl Extended-Release Capsules CD may result in a more rapid release of the dose of methylphenidate.

Priapism

Advise patients, caregivers, and family members of the possibility of painful or prolonged penile erections (priapism). Instruct the patient to seek immediate medical attention in the event of priapism.

Circulation problems in fingers and toes [Peripheral vasculopathy, including Raynaud's phenomenon]

• Instruct patients beginning treatment with Methylphenidate HCl Extended-Release Capsules CD about the risk of peripheral vasculopathy, including Raynaud's Phenomenon, and associated signs and symptoms: fingers or toes may feel numb, cool, painful, and/or may change color from pale, to blue, to red
• Instruct patients to report to their physician any new numbness, pain, skin color change, or sensitivity to temperature in fingers or toes.
• Instruct patients to call their physician immediately with any signs of unexplained wounds appearing on fingers or toes while taking Methylphenidate HCl Extended-Release Capsules CD
• Further clinical evaluation (e.g., rheumatology referral) may be appropriate for certain patients.

Prescribers or other health professionals should inform patients, their families, and their caregivers about the benefits and risks associated with treatment with methylphenidate and should counsel them in its appropriate use. A patient Medication Guide is available for Methylphenidate HCl Extended-Release Capsules CD. The prescriber or healthcare professional should instruct patients, their families, and their caregivers to read the Medication Guide and should assist them in understanding its contents. Patients should be given the opportunity to discuss the contents of the Medication Guide and to obtain answers to any questions they may have. The complete text of the Medication Guide is reprinted at the end of this document. The Medication Guide may also be obtained by calling 1-866-822-0068.

Drug Interactions

Because of possible effects on blood pressure, Methylphenidate HCl Extended-Release Capsules CD should be used cautiously with pressor agents.

Human pharmacologic studies have shown that methylphenidate may inhibit the metabolism of coumarin anticoagulants, anticonvulsants (e.g., phenobarbital, phenytoin, primidone), phenylbutazone and some antidepressants (tricyclics and selective serotonin reuptake inhibitors). Downward dose adjustment of these drugs may be required when given concomitantly with methylphenidate. It may be necessary to adjust the dosage and monitor plasma drug concentrations (or, in the case of coumarin, coagulation times), when initiating or discontinuing concomitant methylphenidate.

In theory, there is a possibility that the clearance of methylphenidate might be affected by urinary pH, either being increased with acidifying agents or decreased with alkalizing agents. This should be considered when methylphenidate is given in combination with agents that alter urinary pH.

Halogenated Anesthetics

There is a risk of sudden blood pressure increase during surgery. If surgery is planned, Methylphenidate HCl Extended-Release Capsules CD should not be taken the day of the surgery.

Carcinogenesis, Mutagenesis, And Impairment Of Fertility

In a lifetime carcinogenicity study carried out in B6C3F1 mice, methylphenidate caused an increase in hepatocellular adenomas and, in males only, an increase in hepatoblastomas, at a daily dose of approximately 60 mg/kg/day. This dose is approximately 30 times and 4 times the maximum recommended human dose of Methylphenidate HCl Extended-Release Capsules CD on a mg/kg and mg/m² basis, respectively. 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.

Methylphenidate did not cause any increases 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 22 times and 5 times the maximum recommended human dose of Methylphenidate HCl Extended-Release Capsules CD on a mg/kg and mg/m² basis, respectively.

In a 24-week carcinogenicity study 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 concentration of methylphenidate as in the lifetime carcinogenicity study; the high-dose groups were exposed to 60 to 74 mg/kg/day of methylphenidate.

Methylphenidate was not mutagenic in the in vitro Ames reverse mutation assay or in the in vitro mouse lymphoma cell forward mutation assay. Sister chromatid exchanges and chromosome aberrations were increased, indicative of a weak clastogenic response, in an in vitro assay in cultured Chinese Hamster Ovary cells. Methylphenidate was negative in vivo in males and females in the mouse bone marrow micronucleus assay.

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 up to 160 mg/kg/day, approximately 80-fold and 8-fold the highest recommended human dose of Methylphenidate HCl Extended-Release Capsules CD on a mg/kg and mg/m² basis, respectively.

Pregnancy

Teratogenic Effects

Pregnancy Category C

Methylphenidate has been shown to have teratogenic effects in rabbits when given in doses of 200 mg/kg/day, which is approximately 100 times and 40 times the maximum recommended human dose on a mg/kg and mg/m² basis, respectively.

A reproduction study in rats revealed no evidence of teratogenicity at an oral dose of 58 mg/kg/day. However, this dose, which caused some maternal toxicity, resulted in decreased postnatal pup weights and survival when given to the dams from day one of gestation through the lactation period. This dose is approximately 30 fold and 6 fold the maximum recommended human dose of Methylphenidate HCl Extended-Release Capsules CD on a mg/kg and mg/m² basis, respectively.

There are no adequate and well-controlled studies in pregnant women. Methylphenidate HCl Extended-Release Capsules CD should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Nursing Mothers

It is not known whether methylphenidate is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised if Methylphenidate HCl Extended-Release Capsules CD is administered to a nursing woman.

Pediatric Use

The safety and efficacy of Methylphenidate HCl Extended-Release Capsules CD in children under 6 years old have not been established. Long-term effects of methylphenidate in children have not been well established (see WARNINGS).