DEXTROAMPHETAMINE SULFATE (dex-troe-am-fet'a-meen) Dexampex, Dexedrine, Oxydess II , Spancap No. 1 Classifications: central nervous system agent; respiratory and cerebral stimulant; amphetamine; anorexiant Prototype: Amphetamine Pregnancy Category: C Controlled Substance: Schedule II
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5 mg, 10 mg tablets; 5 mg, 10 mg, 15 mg sustained release capsules
Dextrorotatory isomer of amphetamine. Anorexigenic action is thought to result from CNS stimulation and possibly from loss
of acuity of smell and taste.
On a weight basis, has less pronounced effect on cardiovascular and peripheral nervous systems and is a more potent appetite
suppressant than amphetamine. CNS stimulating effect approximately twice that of racemic amphetamine. In hyperkinetic children,
amphetamines reduce motor restlessness by an unknown mechanism.
Adjunct in short-term treatment of exogenous obesity, narcolepsy, and attention deficit disorder with hyperactivity in children
(also called minimal brain dysfunction or hyperkinetic syndrome).
Adjunct in epilepsy to control ataxia and drowsiness induced by barbiturates; to combat sedative effects of trimethadione
in absence seizures.
Hypersensitivity to sympathomimetic amines, glaucoma, agitated states, psychoses (especially in children), advanced arteriosclerosis,
symptomatic heart disease, moderate to severe hypertension, hyperthyroidism, history of drug abuse, during or within 14 d
of MAO inhibitor therapy, as anorexiant in children <12 y, for attention deficit disorder in children <3 y, lactation.
Pregnancy (category C). Safety and efficacy in children <3 y have not been established.
Narcolepsy Adult: PO 520 mg 13 times/d at 46 h intervals Child: PO 612 y, 5 mg/d, may increase by 5 mg at weekly intervals; >12 y, 10 mg/d, may increase by 10 mg at weekly intervals
Attention Deficit Disorder Child: PO 35 y, 2.5 mg 12 times/d, may increase by 2.5 mg at weekly intervals; 6 y, 5 mg 12 times/d, may increase by 5 mg at weekly intervals (max: 40 mg/d)
Obesity Adult: PO 510 mg 13 times/d or 1015 mg of sustained release once/d 3060 min a.c.
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Oral
- Ensure that sustained release capsule is not chewed or crushed. It MUST be swallowed whole.
- Give 3060 min before meals for treatment of obesity. Give long-acting form in the morning.
- Give last dose no later than 6 h before patient retires (1014 h before bedtime for sustained release form) to avoid
insomnia.
- Store in tightly closed containers at 15°30° C (59°86° F) unless otherwise directed.
CNS: Nervousness, restlessness, hyperactivity, insomnia, euphoria, dizziness, headache; with prolonged use severe depression, psychotic reactions. CV: Palpitation, tachycardia, elevated BP. GI: Dry mouth, unpleasant taste, anorexia, weight loss, diarrhea, constipation, abdominal pain. Other: Impotence, changes in libido, unusual fatigue, increased intraocular pressure, marked dystonia of head, neck, and extremities;
sweating.
Dextroamphetamine may cause significant elevations in plasma corticosteroids (evening levels are highest) and increases in urinary epinephrine excretion (during first 3 h after drug administration).
Drug: Acetazolamide, sodium bicarbonate decrease dextroamphetamine elimination; ammonium chloride, ascorbic acid increase dextroamphetamine elimination; effects of both barbiturates and dextroamphetamine may be antagonized; furazolidone may increase BP effects of amphetaminesinteraction may persist for several weeks after discontinuing furazolidone; antagonizes antihypertensive effects of guanethidine, guanadrel; mao inhibitors, selegiline can causehypertensive crisis (fatalities reported)do not administer amphetamines during or within 14 d of these drugs; phenothiazines may inhibit mood elevating effects of amphetamines; tricyclic antidepressants enhance dextroamphetamine effects because of increased norepinephrine release; beta-adrenergic agonists increase cardiovascular adverse effects.
Absorption: Rapid. Peak: 15 h. Duration: Up to 10 h. Distribution: All tissues especially the CNS. Metabolism: Metabolized in liver. Elimination: Renal elimination; excreted in breast milk. Half-Life: 1030 h.
Assessment & Drug Effects
- Monitor growth rate closely in children.
- Interrupt therapy or reduce dosage periodically to assess effectiveness in behavior disorders.
- Note: Tolerance to anorexiant effects may develop after a few weeks, however, tolerance does not appear to develop when dextroamphetamine
is used to treat narcolepsy.
Patient & Family Education
- Swallow sustained release capsule whole with a liquid; do not chew or crush.
- Do not drive or engage in other potentially hazardous activities until response to drug is known.
- Taper drug gradually following long-term use to avoid extreme fatigue, mental depression, and prolonged sleep pattern.
- Do not breast feed while taking this drug.