dexmethylphenidate hydrochloride

dexmethylphenidate hydrochloride

Focalin

Pharmacologic class: Methylphenidate derivative

Therapeutic class: CNS stimulant

Controlled substance schedule II

Pregnancy risk category C

FDA Boxed Warning

• Give cautiously to patient with history of drug dependence or alcoholism. Chronic abuse can cause marked tolerance and psychological dependence with abnormal behavior. Frank psychotic episodes may occur, especially with parenteral abuse. During withdrawal from abusive use, provide careful supervision, as severe depression may occur.
• Withdrawal after prolonged therapeutic use may unmask symptoms of underlying disorder that may require follow-up.

Action

Thought to block norepinephrine and dopamine reuptake, increasing the concentration of these neurotransmitters in extraneuronal space

Availability

Tablets: 2.5 mg, 5 mg, 10 mg

⊘Indications and dosages

➣ Attention deficit hyperactivity disorder

Adults and children over age 6: In patients not receiving methylphenidate concurrently, 2.5 mg P.O. b.i.d. at least 4 hours apart; increase as needed in 2.5- to 5-mg increments to a maximum of 10 mg b.i.d. (Individualize dosage according to patient needs and response.) In patients receiving methylphenidate concurrently, start with half of methylphenidate dosage; maximum dosage is 10 mg P.O. b.i.d.

Contraindications

• Hypersensitivity to drug
• Glaucoma
• Anxiety, agitation, tension
• Family history or diagnosis of Tourette syndrome
• MAO inhibitor use within past 14 days

Precautions

Use cautiously in:
• hypertension, depression, seizures, cardiovascular disorders, psychosis, drug abuse
• pregnant or breastfeeding patients
• children under age 6 (safety and efficacy not established).

Administration

• Administer at same time each day without regard to meals.
• Give last dose at least 8 hours before bedtime to prevent insomnia.
• Don't give within 14 days of MAO inhibitor use.

Route	Onset	Peak	Duration
P.O.	Variable	1-1.5 hr	Unknown

Adverse reactions

CNS: nervousness, insomnia, dizziness, drowsiness, headache, dyskinesia, chorea, Tourette syndrome, toxic psychosis

CV: increased or decreased heart rate and blood pressure, tachycardia, angina, palpitations, arrhythmias

EENT: blurred vision, visual accommodation problems

GI: nausea, abdominal pain

Hematologic: anemia, leukopenia, thrombocytopenia

Hepatic: hepatic dysfunction, hepatic coma

Skin: rash, alopecia

Other: fever, decreased appetite, weight loss, psychological drug dependence, drug tolerance, growth suppression in children (with long-term use)

Interactions

Drug-drug. Anticoagulants, phenobarbital, phenytoin, primidone, selective serotonin reuptake inhibitors, tricyclic antidepressants: inhibited metabolism and additive effects of these drugs

Antihypertensives, pressor agents (dopamine, epinephrine): decreased efficacy of these drugs

MAO inhibitors: severe hypertensive crisis

Patient monitoring

☞ Monitor blood pressure closely, especially in patients receiving antihypertensives concurrently.
• Evaluate cardiac status. Report palpitations and other signs and symptoms of arrhythmias.
• During prolonged therapy, regularly monitor CBC with white cell differential and platelet count.

Patient teaching

• Advise patient or parents that drug should be taken at same time each day.
• Tell patient or parents that drug usually is discontinued if symptoms don't improve within 1 month.
• Instruct parents to monitor child's height and weight, because CNS stimulants have been associated with growth suppression.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs mentioned above.