dexmethylphenidate hydrochloride
dexmethylphenidate hydrochloride
Pharmacologic class: Methylphenidate derivative
Therapeutic class: CNS stimulant
Controlled substance schedule II
Pregnancy risk category C
FDA Box 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
Capsules (extended-release): 5 mg, 10 mg, 15 mg, 20 mg, 25 mg, 30 mg, 35 mg, 40 mg
Tablets: 2.5 mg, 5 mg, 10 mg
Indications and dosages
➣ Attention deficit hyperactivity disorder
Adults and children older than age 6: Tablets-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.
Capsules-In adults not receiving methylphenidate concurrently, 10 mg P.O. daily in morning; increase as needed in 10-mg increments approximately weekly to maximum of 20 mg daily. In children not receiving methylphenidate concurrently, 5 mg daily in morning; increase as needed in 5-mg increments approximately weekly to maximum of 20 mg daily. In adults and children receiving methylphenidate concurrently, start with half of methylphenidate total daily dosage.
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.
• Know that regular-release tablets may be switched to same daily dosage as extended-release capsules.
• If necessary, open capsules, sprinkle contents over spoonful of applesauce, and administer immediately.
• Don't give within 14 days of MAO inhibitor use.
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
See 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.
• Instruct patient not to crush or chew capsule. If patient is unable to swallow capsules whole, advise him to open capsules, sprinkle contents over spoonful of applesauce, and take immediately.
• 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.