Names and pronunciation
(dex-troe-am-fet′a-meen) Dexedrine, ProCentra, Zenzedi
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Drug reference
(dex-troe-am-fet′a-meen) Dexedrine, ProCentra, Zenzedi
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Func. class.: Cerebral stimulant
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Chem. class.: Amphetamine Controlled Substance Schedule II
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ACTION: Increases release of norepi- nephrine, DOPamine in cerebral cortex to reticular activating system
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USES: Narcolepsy, attention-deficit/ hyperactivity disorder (ADHD)
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CONTRAINDICATIONS: Hyper- sensitivity to sympathomimetic amines, hyperthyroidism, glaucoma, severe arteriosclerosis
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Black Box Warning: Substance abuse Precautions: Pregnancy, breastfeeding, children <3 yr, depression, Gilles de la Tourette’s disorder, cardiomyopathy, bipolar disorder, abrupt discontinuation, acute MI; benzyl alcohol, salicylate hypersensitivity; hypercortisolism, obesity, psychosis, seizure disorder, hypertension, anxiety, anorexia nervosa, tartrazine dye hypersensitivity Black Box Warning: Symptomatic car- diac disease Black Box Warning: Cardiac disease: VS, B/P; product may reverse antihyper- tensives; check patients with cardiac disease often Black Box Warning: Substance abuse: use for prolonged periods may lead to dependence; sudden death or serious CV events can occur from misuse; chronic intoxication (insomnia, irritability, person- ality changes) • CBC, urinalysis; with diabetes: blood glu- cose, urine glucose; insulin changes may be required because eating will decrease • Height, growth rate in children (growth rate may be decreased), weight • Toxicity: symptoms may vary in children; anxiety, headache, flushing, vom- iting, rhabdomyolysis, tremor, hyperre- flexia, confusion, euphoria, tachycardia • ADHD: change in behavior, growth re- tardation in children • Mental status: mood, sensorium, af- fect, stimulation, insomnia, irritability • Tolerance or dependency: increased amount may be used to get same effect; will develop after long-term use • Pregnancy/breastfeeding: no well- controlled studies; use only if benefit outweighs fetal risk; infants may show withdrawal and low birth weight, avoid breastfeeding, excreted in breast milk
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SIDE EFFECTS CNS: Hyperactivity, insomnia, restless- ness, talkativeness, dizziness, headache, chills, stimulation, dysphoria, irritability, aggressiveness, tremor, dependence, addiction CV: Palpitations, tachycardia, hyperten- sion, decrease in heart rate, dysrhythmias GI: Anorexia, dry mouth, diarrhea, con- stipation, weight loss, metallic taste GU: Impotence, change in libido INTEG: Urticaria MISC: Rhabdomyolysis
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INTERACTIONS Increase: hypertensive crisis: MAOIs or within 14 days of MAOIs Increase: serotonin syndrome, neurolep- tic malignant syndrome: SSRIs, SNRIs, serotonin-receptor agonists; do not use concurrently Increase: dextroamphetamine effect— acetaZOLAMIDE Increase: CNS effect—haloperidol, tricy- clics, phenothiazines Decrease: absorption of barbiturates, phenytoin Decrease: dextroamphetamine effect— ascorbic acid, ammonium chloride Decrease: effect of adrenergic blockers, antidiabetics, antihypertensives, anti histamines Drug/Herb • Serotonin syndrome—St. John’s wort Decrease: stimulant effect—eucalyptus Drug/Food Increase: amine effect—caffeine (cola, coffee, tea [green/black]) Decrease: effect—fruit juice (oral solution) Drug/Lab Test Increase: plasma corticosteroids, urinary steroids
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TREATMENT OF OVERDOSE: Administer fluids, hemodialysis; antihy- pertensive for increased B/P, ammonium chloride for increased excretion
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DOSAGE AND ROUTES Narcolepsy • Adult: PO 5 mg bid, titrate daily dose by no more than 10 mg/wk, max 60 mg/day • Child 6-12 yr: PO 5 mg/day, titrate daily dose by no more than 5 mg/day at weekly intervals, max 40 mg/day ADHD • Adult: PO 5-60 mg/day daily or di- vided bid, max 40 mg/day • Child 3-5 yr: PO 2.5 mg/day increas- ing by 2.5 mg/day at weekly intervals, max 40 mg/day • Child >6-12 yr: PO 5 mg daily-bid in- creasing by 5 mg/day at weekly intervals, max 40 mg/day
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Available forms: Tablets 2.5, 5, 7.5, 10, 15, 20, 30 mg; oral solution 5 mg/5 mL; extended-release capsules 5, 10, 15 mg
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Administer: • At least 6 hr prior to bedtime to avoid sleeplessness • Use calibrated measuring device for oral solution • Store all forms at room temperature
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Assess:
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Evaluate: • Therapeutic response: increased CNS stimulation, except in ADHD, decreased drowsiness
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CLINICAL CONSIDERATIONS
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Patient and caregiver information: • To take before meals (obesity) • To decrease caffeine consumption (coffee, tea, cola, chocolate); may in- crease irritability, stimulation • To avoid OTC preparations unless ap- proved by prescriber; to avoid alcohol ingestion; to avoid fruit juice at same time as solution, effect is decreased • To tell parents that change in behavior may occur in beginning treatment, irrita- bility, hostility • Seizures: that those with a seizure disorder may have decreased seizure threshold • To taper product over several weeks; depression, increased sleeping, lethargy may occur • To avoid hazardous activities until sta- bilized on medication • To get needed rest; patient will feel more tired at end of day
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PHARMACOKINETICS Onset 30-60 min, peak 2 hr, duration 4 hr; extended release onset 1 hr, peak 2 hr, duration 8 hr; metabolized by liver; urine excretion pH dependent; crosses placenta, breast milk; half-life 6-8 hr (child), 10-12 hr (adult)
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• Adult: PO 5 mg bid, titrate daily dose by no more than 10 mg/wk, max 60 mg/day
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• Child 6-12 yr: PO 5 mg/day, titrate daily dose by no more than 5 mg/day at weekly intervals, max 40 mg/day ADHD
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• Adult: PO 5-60 mg/day daily or di- vided bid, max 40 mg/day
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• Child 3-5 yr: PO 2.5 mg/day increas- ing by 2.5 mg/day at weekly intervals, max 40 mg/day
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• Child >6-12 yr: PO 5 mg daily-bid in- creasing by 5 mg/day at weekly intervals, max 40 mg/day
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