Methylphenidate HCl

A to Z Drug Facts

 Action Acts as mild cortical stimulant with CNS action; exact mechanism of action unknown.

 Indications Treatment of attention-deficit hyperactivity disorder (ADHD); treatment of narcolepsy.

 Contraindications Marked anxiety, agitation, and tension; glaucoma; motor tics; family history or diagnosis of Tourette syndrome; concurrent treatment with MAO inhibitors and within a minimum of 14 days following discontinuation of a MAO inhibitor.

 Route/Dosage

ADULTS: PO 10 to 60 mg/day in 2 to 3 divided doses. CHILDREN 6 YR AND OLDER: PO 5 mg before breakfast and lunch initially; increase by increments of 5 to 10 mg/wk up to 60 mg/day. Give sustained-release (SR) tablets at 8-hr intervals. ADULTS AND CHILDREN (6 YR AND OLDER): PO Concerta: In patients new to methylphenidate, start with 18 mg once daily in the morning, then adjust dose in 18 mg increments at weekly intervals (max, 54 mg once daily in the morning). In patients being converted from methylphenidate regimens to Concerta, start with 18 mg of Concerta every morning in patients receiving methylphenidate 5 mg bid or tid or 20 mg SR; start with 36 mg of Concerta every morning in patients receiving methylphenidate 10 mg bid or tid or 40 mg SR; start with 54 mg of Concerta every morning for patients receiving methylphenidate 15 mg bid or tid or 60 mg SR. The dose of Concerta may be adjusted in 18 mg increments at weekly intervals (max, 54 mg once daily in the morning). Metadate CD: Start with 20 mg once daily in the morning before breakfast, then adjust dose in 20 mg increments at weekly intervals (max, 60 mg once daily in the morning). Ritalin LA: Start with 20 mg once daily in the morning, then adjust dose in 10 mg increments at weekly intervals (max, 60 mg once daily in the morning).

 Interactions

Anticonvulsants (eg, phenobarbital, phenytoin, primidone), selective serotonin reuptake inhibitors (eg, fluoxetine), tricyclic antidepressants (eg, imipramine): Plasma levels of these agents may be increased by methylphenidate, increasing the risk of side effects. Guanethidine: The antihypertensive effects of guanethidine may be decreased. MAO inhibitors (eg, phenelzine): Because of the risk of hypertensive crisis, methylphenidate is contraindicated in patients receiving MAO inhibitors and for a minimum of 14 days after discontinuation of a MAO inhibitor.

 Lab Test Interferences None well documented.

 Adverse Reactions

CV: Changes in pulse and BP; tachycardia; angina; cardiac arrhythmias; palpitations. CNS: Nervousness; insomnia; dizziness; headache; dyskinesias; drowsiness; convulsions; toxic psychosis. EENT: Blurred vision. GI: Anorexia; nausea; abdominal pain; weight loss during prolonged therapy. HEMA: Leukopenia; anemia. OTHER: Hypersensitivity reactions (eg, rash, itching, fever, joint pain, exfoliative dermatitis, erythema multiforme, thrombocytopenia purpura).

 Precautions

Pregnancy: Category C. Lactation: Undetermined. Children: Do not give to children less than 6 yr because safety and efficacy not established. Carefully monitor children on long-term therapy, especially for growth in height and weight gain. Dependence: Chronic use may lead to tolerance, psychological dependence, and abnormal behavior. Use with caution in patients with history of drug abuse. Monitor withdrawal from drug therapy for symptoms that can include severe depression. Hypertension: Use drug with caution; monitor BP. Seizure disorders: Drug may lower seizure threshold in susceptible patients. Safe concomitant use with anticonvulsants is not established. If seizures occur, notify health care provider and consider withholding drug. Depression/Fatigue: Do not use to treat severe depression or normal fatigue. GI obstruction: Because Concerta tablet is nondeformable and does not change shape in the GI tract, do not administer to patients with pre-existing severe GI narrowing. Psychosis: Symptoms of behavior disturbances and thought disorder may be exacerbated.

 Administration/Storage

• Discontinue MAO inhibitors at least 14 days before initiating treatment.
• Administer last daily dose 6 hr before bedtime to avoid sleeplessness.
• Do not crush or chew SR tablet. Instruct patient to swallow SR tablet whole.
• Store at room temperature.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies. Note history of drug abuse, alcoholism, hypertension, liver disease, glaucoma, motor tics, seizures, Tourette syndrome, and family history of Tourette syndrome.
• Obtain psychological history noting anxiety, agitation, or tension.
• With parental permission, consult with school personnel regarding drug effectiveness.
• Discontinue drug periodically to assess behavior and determine need to continue drug.
• Evaluate ability of family to comply with regimen and follow-up. Assist with problem-solving barriers that inhibit compliance.
• Promote holistic team approach to management of ADHD including parents, day care providers, school personnel, and health care providers.
• Monitor height and weight in children.
• Monitor vital signs, noting increase in BP.
• Monitor for drug effectiveness, hypersensitivity, and side effects, especially insomnia, tremors, restlessness, anorexia, and tachycardia.
• Monitor for depression of psychotic reaction when drug is discontinued after long-term use.
• Monitor CBC, differential, and platelet counts if patient is undergoing long-term treatment.
• Monitor sleep habits in adults.

 Patient/Family Education

• Instruct patient to take last daily dose 6 hr before bedtime or to take extended-release form (Concerta or Metadate CD) in the morning to avoid insomnia.
• Stress importance of complying with follow-up appointments and lab work.
• Instruct patient to measure weight 2 to 3 times/wk and report weight loss to health care provider.
• Advise parents regarding behavior management of children and coping strategies.
• Instruct parent to provide relaxing environment at bedtime with sleep rituals to promote sleep and prevent insomnia.
• Advise parents to alert school or day care personnel about drug use and administration.
• Refer parents to ADHD support group.
• Instruct patient to report the following symptoms to health care provider: nervousness, insomnia, palpitations, vomiting, fever, or rash.
• Suggest that patient take sips of water frequently, suck on ice chips or sugarless hard candy, or chew sugarless gum if dry mouth occurs.
• Instruct patient to avoid intake of caffeine and alcoholic beverages.
• Advise patient that drug may cause drowsiness and to use caution while driving or performing other tasks requiring mental alertness.
• Instruct patient not to take OTC medications without consulting health care provider.
• Advise patient to take SR products whole and not to open, crush, or chew them.

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Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts