methylphenidate hydrochloride

methylphenidate hydrochloride

(meth ill fen' i date)

Concerta, Metadate CD, Metadate ER, Methylin, Methylin ER, PMS-Methylphenidate (CAN), Ritalin, Ritalin LA, Ritalin SR

Pregnancy Category C

Controlled Substance C-II

Drug class

CNS stimulant

Therapeutic actions

Mild cortical stimulant with CNS actions similar to those of the amphetamines; efficacy in hyperkinetic syndrome, attention-deficit disorders in children appearsparadoxical and is not understood

Indications

·        Ritalin, Ritalin SR, Metadate ER, Methylin: Narcolepsy

·        Attention-deficit disorders, hyperkinetic syndrome, minimal brain dysfunction in children or adults with a behavioral syndrome characterized by the following symptoms: Moderate to severe distractibility, short attention span, hyperactivity, emotional lability, and impulsivity, not secondary to environmental factors or psychiatric disorders

·        Unlabeled use: Treatment of depression in the elderly, cancer and stroke patients; alleviation of neurobehavioral symptoms after traumatic brain injury; improvement in pain control and sedation in patients receiving opiates

Contraindications and cautions

·        Contraindicated with hypersensitivity to methylphenidate; marked anxiety, tension, and agitation; glaucoma; motor tics, family history or diagnosis of Tourettesyndrome; severe depression of endogenous or exogenous origin; normal fatigue states.

·        Use cautiously with seizure disorders; hypertension; drug dependence, alcoholism; emotional instability; lactation, pregnancy.

Available forms

Tablets—5, 10, 20 mg; chewable tablets—2.5, 5, 10 mg; SR tablets—20 mg; ER tablets—10, 18, 20, 27, 36, 54 mg; ER capsules—20, 30 mg (Metadate CD); and 20, 30, 40 mg (Ritalin LA)

Dosages

ADULTS

Individualize dosage. Give orally in divided doses bid or tid, preferably 30–45 min before meals; dosage ranges from 10–60 mg/day PO. If insomnia is a problem, drug should be taken before 6 PM. Timed-release tablets have a duration of 8 hr and may be used when timing and dosage are adjusted to the 8-hr daily regimen. ER forms: 18 mg PO daily in the morning; may be increased by 18 mg/day at 1-wk intervals to a maximum of 54 mg/day (Concerta); 20 mg/day to a maximum 60 mg/day (Metadate CD, Ritalin LA).

PEDIATRIC PATIENTS 13-17 YR

Initially 18 mg/day PO taken in the morning without regard to food; titrate to a maximum 72 mg/day PO. Do not exceed 2 mg/kg/day. Tablets must be swallowed whole and should not be cut, crushed, or chewed (Concerta).

PEDIATRIC PATIENTS > 6 YR

Start with small oral doses (5 mg PO before breakfast and lunch with gradual increments of 5–10 mg weekly). Daily dosage > 60 mg not recommended. Discontinue use after 1 mo if no improvement. Discontinue periodically to assess condition; usually discontinued after puberty. ER forms: Use adult dosage.

PEDIATRIC PATIENTS < 6 YR

Not recommended.

Pharmacokinetics

Route	Onset	Peak	Duration
Oral	Varies	1–3 hr	4–6 hr

Metabolism: Hepatic; T_1/2: 1–3 hr (6.8 hr ER)

Distribution: Crosses placenta; may enter breast milk

Excretion: Urine

Adverse effects

·        CNS: Nervousness, insomnia, dizziness, headache, dyskinesia, chorea, drowsiness, Tourette syndrome, toxic psychosis, blurred vision, accommodation difficulties

·        CV: Increased or decreased pulse and BP; tachycardia, angina, cardiac arrhythmias, palpitations

·        Dermatologic: Rash, urticaria, fever, arthralgia, exfoliative dermatitis, erythema multiforme with necrotizing vasculitis and thrombocytopenic purpura, loss of scalp hair

·        GI: Anorexia, nausea, abdominal pain, weight loss

·        Hematologic: Leukopenia, anemia

·        Other: Tolerance, psychological dependence, abnormal behavior with abuse

Interactions

Drug-drug

·        Decreased effects of guanethidine; avoid this combination

·        Increased effects and toxicity of methylphenidate with MAOIs

·        Increased serum levels of phenytoin, TCAs, oral anticoagulants, SSRIs with methylphenidate; monitor for toxicity

Drug-lab test

·        Methylphenidate may increase the urinary excretion of epinephrine

Nursing considerations

Assessment

·        History: Hypersensitivity to methylphenidate; marked anxiety, tension, and agitation; glaucoma; motor tics, Tourette syndrome; severe depression; normal fatigue state; seizure disorders; hypertension; drug dependence, alcoholism, emotional instability; pregnancy, lactation

·        Physical: Weight; T; skin color, lesions; orientation, affect, ophthalmologic examination (tonometry); P, BP, auscultation; R, adventitious sounds; bowel sounds, normal output; CBC with differential, platelet count, baseline ECG

Interventions

·        Ensure proper diagnosis before administering to children for behavioral syndromes; drug should not be used until other causes or concomitants of abnormal behavior (learning disability, EEG abnormalities, neurologic deficits) are ruled out.

·        Interrupt drug dosage periodically in children to determine if symptoms warrant continued drug therapy.

·        Monitor growth of children on long-term methylphenidate therapy.

·        Ensure that all timed-release tablets and capsules are swallowed whole, not chewed or crushed.

·        Dispense the smallest feasible dose to minimize risk of overdose.

·        Give before 6 PM to prevent insomnia.

·        Monitor CBC and platelet counts periodically in patients on long-term therapy.

·        Monitor BP frequently early in treatment.

Teaching points

·        Take this drug exactly as prescribed. Timed-release tablets and capsules must be swallowed whole, not chewed or crushed. Metadate CD capsules may be opened and entire contents sprinkled on soft food—do not chew or crush granules.

·        Take drug before 6 PM to avoid nighttime sleep disturbance.

·        Avoid alcohol and over-the-counter drugs, including nose drops, cold remedies; some over-the-counter drugs could cause dangerous effects.

·        You may experience these side effects: Nervousness, restlessness, dizziness, insomnia, impaired thinking (may lessen; avoid driving or engaging in activities that require alertness); headache, loss of appetite, dry mouth.

·        Keep drug in secure place; do not share with others.

·        Report nervousness, insomnia, palpitations, vomiting, rash, fever.

Adverse effects in Italic are most common; those in Bold are life-threatening.