lisdexamfetamine dimesylate

Action

Rapidly absorbed and converted to dextroamphetamine, which is responsible for CNS activity. Therapeutic action in attention deficit hyperactivity disorder (ADHD) is unknown.

Availability

Capsules: 20 mg, 30 mg, 40 mg, 50 mg, 60 mg, 70 mg

Indications and dosages

➣ ADHD

Adults and Children ages 6 to 12: Individualize dosage based on therapeutic needs and response. For child starting treatment for first time or switching from another drug, recommended dosage is 30 mg P.O. once daily in morning. If daily dosage will be increased above 30 mg, adjust in increments of 10 to 20 mg/day at approximately weekly intervals. Maximum recommended dosage is 70 mg/day.

Contraindications

• Hypersensitivity or idiosyncratic reaction to sympathomimetic amines

• Advanced arteriosclerosis, symptomatic cardiovascular disease, moderate to severe hypertension, hyperthyroidism, glaucoma, agitated state

• History of drug abuse

• During or within 14 days of MAO inhibitor therapy

Precautions

Use cautiously in:

• concurrent use of other sympathomimetics

• tics, Tourette syndrome, hypertension or other cardiovascular conditions, preexisting psychosis (such as bipolar disorder)

• electroencephalogram (EEG) abnormalities or seizures

• pregnant and breastfeeding patients

• adults

• children younger than age 6 or older than age 12 (safety and efficacy not established).

Administration

• Administer with or without food.

• Give in morning to avoid insomnia.

• Give capsules whole, or open and dissolve entire contents in glass of water. When using solution method, don't divide single-capsule dose; make sure patient consumes solution immediately.

See Don't give within 14 days of MAO inhibitors.

Adverse reactions

CNS: dizziness, headache, somnolence, insomnia, irritability, labile affect, manic symptoms, dysphoria, euphoria, aggression, restlessness, tics, dyskinesia, psychomotor hyperactivity, psychotic episodes, depression, tremor, seizure, stroke

CV: palpitations, tachycardia, hypertension, ventricular hypertrophy, myocardial infarction, cardiomyopathy, sudden death

EENT: visual disturbances

GI: abdominal pain, nausea, vomiting, diarrhea, constipation, dry mouth, unpleasant taste

GU: libido changes, erectile dysfunction

Skin: rash, toxic epidermal necrolysis, urticaria, Stevens-Johnson syndrome

Other: decreased appetite, weight loss, growth suppression, fever, amphetamine tolerance and dependency, hypersensitivity reactions including angioedema and anaphylaxis

Interactions

Drug-drug. Adrenergic blockers: inhibited adrenergic blocker action

Antihistamines: decreased sedative effect of antihistamine

Antihypertensives: antagonism of anti-hypertensive effect

Chlorpromazine: inhibited stimulant effect

Desipramine, protriptyline (and possibly other tricyclic antidepressants): enhanced antidepressant activity, causing sustained rise in d-amphetamine concentration in brain

Ethosuximide: delayed intestinal absorption of this drug

Haloperidol: inhibited central stimulant effects

Lithium carbonate: inhibited anorectic and stimulatory effects of lisdexamfetamine

MAO inhibitors: slowed lisdexamfetamine metabolism, possibly leading to hypertensive crises

Meperidine: potentiated analgesic effect of meperidine

Methenamine therapy: increased amphetamine urinary excretion, causing reduced lisdexamfetamine blood level and efficacy

Norepinephrine: enhanced norepinephrine adrenergic effect

Phenobarbital, phenytoin: possible delayed intestinal absorption of these drugs, possible synergistic anticonvulsant action

Propoxyphene: increased risk of potentiated CNS stimulation (leading to life-threatening seizures in propoxyphene overdosage)

Drug-diagnostic tests. Plasma corticosteroids: increased levels

Urinary steroids: interference with results

Drug-herbs. Veratrum alkaloids, such as Veratrum album (white hellebore), V. eschsholtzii (American hellebore), and V. luteum (false unicorn): inhibited hypotensive effect of these herbs

Patient monitoring

• Before initiating therapy, evaluate patient and family for history of cardiovascular abnormalities, tics or Tourette syndrome (or exacerbation of these), EEG abnormalities, and seizures. Drug may lower seizure threshold.

• During early treatment phase, stay alert for worsening of aggressive behavior or hostility.

• Monitor blood pressure and pulse.

• Know that when possible, drug therapy should be interrupted occasionally to determine if behavioral symptoms recur to extent that necessitates continued therapy.

• Monitor patient for appropriate growth and weight gain.

• Watch for signs and symptoms of drug tolerance, dependence, and abuse.

Patient teaching

• Inform patient or caregiver that drug can be taken with or without food. Advise them that it should be taken in morning to help avoid insomnia.

• Instruct patient to take capsule whole, or to open it and dissolve entire contents in glass of water, and consume solution immediately.

• Advise patient or caregiver to watch for and report seizures, worsening of aggressive behavior, tics, or inappropriate growth or weight gain.

• Instruct patient to avoid using herbs unless prescriber approves.

• Caution patient to avoid hazardous activities until drug's effects on concentration, coordination, and vision are known.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and herbs mentioned above.