2.1 Pretreatment Screening

Prior to initiating treatment with methylphenidate hydrochloride oral solution, assess for the presence of cardiac disease (i.e., perform a careful history including family history of sudden death or ventricular arrhythmia, and physical examination) [see Warnings and Precautions (5.2)].

Assess the risk of abuse prior to prescribing, and monitor for signs of abuse and dependence while   on therapy. Maintain careful prescription records, educate patients about abuse, monitor for signs of abuse and overdose, and periodically re-evaluate the need for methylphenidate hydrochloride oral solution use [see Boxed Warning, Warnings and Precautions (5.1), Drug Abuse and Dependence (9)].

2.2 General Dosing Information

Pediatric Patients 6 years of Age and Older
The recommended starting dosage is 5 mg orally twice daily before breakfast and lunch (preferably 30  to 45 minutes before meals). Increase the dosage gradually, in increments of 5 mg to 10 mg weekly. Daily dosage above 60 mg is not recommended.

Adults
Administer orally in divided doses 2 or 3 times daily, preferably 30 to 45 minutes before meals. The maximum recommended daily dose is 60 mg. The average dosage is 20 to 30 mg daily. For adult patients who are unable to sleep if medication is taken late in the day, administer the last dose before 6 p.m.

Pharmacological treatment of ADHD may be needed for extended periods. Periodically re-evaluate the long-term use of methylphenidate hydrochloride oral solution, and adjust the dosage as needed.

2.3 Dosage Reduction and Discontinuation

If paradoxical aggravation of symptoms or other adverse reactions occur, reduce dosage, or, if necessary, discontinue methylphenidate hydrochloride oral solution. Methylphenidate hydrochloride oral solution should be periodically discontinued to assess the pediatric patient’s condition. If improvement is not observed after appropriate dosage adjustment over a one- month period, discontinue methylphenidate hydrochloride oral solution.

5.1 Potential for Abuse and Dependence

CNS stimulants, including methylphenidate hydrochloride oral solution, other methylphenidate-containing products, and amphetamines, have a high potential for abuse and dependence. Assess the risk of abuse prior to prescribing, and monitor for signs of abuse and dependence while on therapy [see Boxed Warning, Drug Abuse and Dependence (9.2, 9.3)].

5.2 Serious Cardiovascular Reactions

Sudden death, stroke and myocardial infarction have been reported in adults with CNS stimulant treatment at recommended doses. Sudden death has been reported in pediatric patients with structural cardiac abnormalities and other serious heart problems taking CNS stimulants at recommended doses for ADHD. Avoid use in patients with known structural cardiac abnormalities, cardiomyopathy, serious  heart rhythm abnormalities, coronary artery disease, and other serious heart problems. Further evaluate patients who develop exertional chest pain, unexplained syncope, or arrhythmias during methylphenidate hydrochloride oral solution treatment.

5.3 Blood Pressure and Heart Rate Increases

CNS stimulants cause an increase in blood pressure (mean increase approximately 2 to 4 mmHg) and  heart rate (mean increase approximately 3 to 6 bpm). Individuals may have larger increases. Monitor all patients for hypertension and tachycardia.

5.4 Psychiatric Adverse Reactions

Exacerbation of Pre-Existing Psychosis

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

Induction of a Manic Episode in Patients with Bipolar Illness
CNS stimulants may induce a manic or mixed mood episode in patients. Prior to initiating 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 doses, may cause psychotic or manic symptoms (e.g., hallucinations, delusional thinking, or mania) in patients without a prior history of psychotic illness or mania. If such symptoms occur, consider discontinuing methylphenidate hydrochloride oral solution. 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 in placebo-treated patients.

5.5 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 during discontinuation). Patients who develop abnormally sustained or frequent and painful erections should seek immediate medical attention.

5.6 Peripheral Vasculopathy, Including Raynaud’s Phenomenon

Stimulants used to treat ADHD, including methylphenidate hydrochloride oral solution, 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 postmarketing 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.

5.7 Long-Term Suppression of Growth

CNS stimulants have been associated with weight loss and slowing of growth rate in pediatric patients.

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 naturalistic 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.

Closely monitor growth (weight and height) in pediatric patients treated with stimulants, including methylphenidate hydrochloride oral solution. Patients who are not growing or gaining height or weight as expected may need to have their treatment interrupted. The safety and effectiveness of methylphenidate hydrochloride oral solution have not been established in pediatric  patient less than 6 years of age.

7.1 Clinically Important Drug Interactions with Methylphenidate Hydrochloride Oral Solution

Table 1 presents clinically important drug interactions with methylphenidate hydrochloride oral solution.

Table 1: Clinically Important Drug Interactions with Methylphenidate Hydrochloride Oral Solution

8.1 Pregnancy

Pregnancy Exposure Registry
There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to ADHD  medications, including methylphenidate hydrochloride oral solution, during pregnancy. Healthcare providers are encouraged to register patients by calling the National Pregnancy Registry for Psychostimulants at 1-866-961-2388.

Risk Summary
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 use during pregnancy (see Clinical Considerations).

No effects on morphological development were observed in embryo-fetal development studies with oral administration of methylphenidate to pregnant rats and rabbits during organogenesis at doses up  to 12 and 19 times, respectively, the maximum recommended human dose (MRHD) of 60 mg/day given to adults on a mg/m 2 basis. However, spina bifida was observed in rabbits at a dose 65 times the MRHD given to adults. A decrease in pup body weight was observed in a pre- and post-natal development study with oral administration of methylphenidate to rats throughout pregnancy and lactation at doses 7 times the MRHD given to adults (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 methylphenidate hydrochloride oral solution, 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, methylphenidate was administered orally at doses of up to 75 and 200 mg/kg/day, respectively, during the period of organogenesis. Malformations (increased incidence of fetal spina bifida) were observed in rabbits at the highest dose, which is approximately 65 times the MRHD of 60 mg/day given to adults on a mg/m 2 basis. The no effect level for embryo-fetal development in rabbits was 60 mg/kg/day (19 times the MRHD given to adults on a mg/m 2 basis). There was no evidence of morphological development effects in rats, although increased incidences of fetal skeletal variations were seen at the highest dose level (12 times the MRHD of 60 mg/day given to adults on a mg/m 2 basis), which was also maternally toxic. The no effect level for embryo-fetal development in rats was 25 mg/kg/day (4 times the MRHD on a mg/m 2 basis). When methylphenidate was administered to rats throughout pregnancy and lactation at doses of up to 45 mg/kg/day, offspring body weight gain was decreased at the highest dose (7 times the MRHD of 60 mg/day given to adults on a mg/m 2 basis), but no other effects on postnatal development were observed. The no effect level for pre- and postnatal development in rats was 15 mg/kg/day (~2 times the MRHD given to adults on a mg/m 2 basis).

8.2 Lactation

Risk Summary
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 methylphenidate hydrochloride oral solution and any potential  adverse effects on the breastfed infant from methylphenidate hydrochloride oral solution or from the underlying maternal condition.

Clinical Considerations
Monitor breastfeeding infants for adverse reactions, such as agitation, insomnia, anorexia, and reduced  weight gain.

8.4 Pediatric Use

The safety and effectiveness of methylphenidate hydrochloride oral solution for the treatment of ADHD have been established in pediatric patients six years of age and older. The safety and effectiveness of methylphenidate hydrochloride oral solution in pediatric patients under  six years of age have not been established. The long-term efficacy of methylphenidate in pediatric patients has not been established.

Long-Term Suppression of Growth
Growth should be monitored during treatment with stimulants, including methylphenidate hydrochloride oral solution. Pediatric patients who are not growing or gaining weight as expected may need to have their treatment interrupted [see Warnings and Precautions (5.6)].

Juvenile Animal Toxicity Data
In a study conducted in young rats, 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 13-14), 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/day 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 (5 mg/kg/day) is less than 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.

8.5 Geriatric Use

Methylphenidate hydrochloride oral solution has not been studied in the geriatric population.

9.1 Controlled Substance

Methylphenidate hydrochloride oral solution contains methylphenidate hydrochloride, a Schedule II controlled substance.

9.2 Abuse

CNS stimulants, including methylphenidate hydrochloride oral solution, other methylphenidate-containing products, and amphetamines have a high potential for abuse. Abuse is the intentional non-therapeutic use of a drug, even once, to achieve a desired psychological or physiological effect. Drug addiction is a cluster of behavioral, cognitive, and physiological phenomena that may include a strong desire to take the drug, difficulties in controlling drug use (e.g., continuing drug use despite harmful consequences, giving a higher priority to drug use than other activities and obligations), and possible tolerance or physical dependence. Both  abuse and misuse may lead to addiction, and some individuals may develop addiction even when taking methylphenidate hydrochloride oral solution as prescribed.

Signs and symptoms of CNS stimulant abuse include increased heart rate, respiratory rate, blood pressure, and/or sweating, dilated pupils, hyperactivity, restlessness, insomnia, decreased appetite, loss of coordination, tremors, flushed skin, vomiting, and/or abdominal pain. Anxiety, psychosis, hostility, aggression, and suicidal or homicidal ideation have also been observed. Individuals who abuse CNS stimulants may chew, snort, inject, or use other unapproved routes of administration which  may result in overdose and death [see Overdosage (10)].

To reduce the abuse of methylphenidate hydrochloride oral solution, assess the risk of abuse prior to prescribing. After prescribing, keep careful prescription records, educate patients and their families about abuse and on proper storage and disposal of CNS stimulants [see How Supplied/Storage and Handling (16)], monitor for signs of abuse while on therapy, and re-evaluate the need for methylphenidate hydrochloride oral solution use.

9.3 Dependence

Physical Dependence
Methylphenidate hydrochloride oral solution may produce physical dependence from continued therapy. Physical dependence is a state of adaptation manifested by a withdrawal syndrome produced by abrupt cessation, rapid dose  reduction, or administration of an antagonist. Withdrawal symptoms after abrupt cessation following prolonged high-dosage administration of CNS stimulants include dysphoric mood; depression; fatigue; vivid, unpleasant dreams; insomnia or hypersomnia; increased appetite; and psychomotor retardation or agitation.

Tolerance
Methylphenidate hydrochloride oral solution may produce tolerance from continued therapy. Tolerance is a state of adaptation in which exposure to a drug results in a reduction of the drug’s desired and/or undesired effects over time).

12.1 Mechanism of Action

Methylphenidate hydrochloride is a central nervous system (CNS) stimulant. The mode of therapeutic action in ADHD is not known.

12.2 Pharmacodynamics

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. Methylphenidate blocks the reuptake of norepinephrine and dopamine into the presynaptic neuron and increases the release of these monoamines into the extraneuronal space.

Cardiac Electrophysiology
A formal QT study has not been conducted in subjects taking methylphenidate hydrochloride oral solution.

The effect of dexmethylphenidate, the pharmacologically active d-enantiomer of methylphenidate hydrochloride oral solution, on the QT  interval was evaluated in a double-blind, placebo- and open-label active (moxifloxacin)-controlled study following single doses of 40 mg dexmethylphenidate hydrochloride extended-release capsule in 75 healthy volunteers. Electrocardiograms were collected up to 12 hours postdose. Frederica’s method for heart rate correction was employed to derive the corrected QT interval (QTcF). The maximum mean prolongation of QTcF intervals was less than 5 ms, and the upper limit of the 90% confidence interval was below 10 ms for all time-matched comparisons versus placebo. This was below the threshold of clinical concern and there was no evident exposure response relationship.

12.3 Pharmacokinetics

Absorption
Following a single dose administration of 20 mg methylphenidate hydrochloride oral solution and 20 mg tablet of methylphenidate hydrochloride in healthy volunteers under fasted conditions, time to peak plasma concentration (T max)  of methylphenidate was at 1 to 2 hours after dosing, and:

• The mean peak plasma concentration (C max) of methylphenidate was 9.1 ng/mL and 9.8 ng/mL, respectively.
• The mean area under concentration curve (AUC) of methylphenidate was 46.7 hour*ng/mL and 50.0 hour*ng/mL, respectively.

Effect of Food
Ingestion of a high-fat meal with methylphenidate hydrochloride oral solution increased methylphenidate mean C max and AUC by about  13% and 25%, respectively. Time to C max (T max) was delayed by approximately 1 hour.

Distribution
Plasma protein binding is 10% to 33%. The volume of distribution was 2.65 ± 1.11 L/kg for d-methylphenidate and 1.80 ± 0.91 L/kg for l-methylphenidate.

Elimination
The mean terminal half-life (t½) of methylphenidate was 2.7 hours following administration of 20 mg  methylphenidate hydrochloride oral solution. The systemic clearance is 0.40 ± 0.12 L/h/kg for d-methylphenidate and 0.73 ± 0.28 L/h/kg for l-methylphenidate.

Metabolism
Methylphenidate is metabolized primarily by deesterification to alpha-phenyl-piperidine acetic acid (ritalinic acid), which has little or no pharmacologic activity.

Excretion
After oral dosing of radiolabeled methylphenidate in humans, about 90% of the radioactivity was recovered in urine. The main urinary metabolite was ritalinic acid, accounting for approximately 80% of  the dose.

Specific Populations
Male and Female Patients, Racial Groups, and Age
The effect of gender, race, and age on the pharmacokinetics of methylphenidate after methylphenidate hydrochloride oral solution administration have not been studied.

Patients with Renal Impairment
Methylphenidate hydrochloride oral solution has not been studied in 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 methylphenidate hydrochloride oral solution.

Patients with Hepatic Impairment
Methylphenidate hydrochloride oral solution has not been studied in patients with hepatic impairment. Since methylphenidate is metabolized primarily to ritalinic acid by nonmicrosomal hydrolytic esterases that are widely distributed throughout the body, hepatic impairment is expected to have minimal effect on the pharmacokinetics of methylphenidate hydrochloride oral solution.

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

Carcinogenesis
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 5 times the maximum recommended human dose (MRHD) of 60 mg/kg given to adults 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.

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 7 times the  MRHD (adults) on a mg/m 2 basis.

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.

Mutagenesis
Methylphenidate 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 vitro chromosomal aberration assay using human lymphocytes. Sister chromatid exchanges and chromosome aberrations were increased, indicative of a weak clastogenic response, in an in vitro assay in cultured Chinese Hamster Ovary (CHO) cells. Methylphenidate was negative in vivo in males and females in the mouse bone marrow micronucleus assay.

Impairment of Fertility
No human data on the effect of methylphenidate on fertility are available. 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 13   times the maximum recommended human dose of 60 mg/day given to adults on a mg/m 2 basis.