AMPHETAMINE SULFATE

(am-fet'a-meen)

Adderall, Adderall XR
Classifications: cerebral stimulant; anorexiant;
Therapeutic: cerebral stimulant
Pregnancy Category: C
Controlled Substance: Schedule II

Availability

5 mg, 10 mg tablets

Adderall: 5 mg, 10 mg, 20 mg, 30 mg tablets; 5 mg, 15 mg, 20 mg, 25 mg, 30 mg sustained release capsules

Action

Marked stimulant effect on CNS thought to be due to action on cerebral cortex and possibly the reticular activating system. Acts indirectly on adrenergic receptors by increasing synaptic release of norepinephrine in the brain and by blocking reuptake of norepinephrine at presynaptic membranes.

Therapeutic Effect

CNS stimulation results in increased motor activity, diminished sense of fatigue, alertness, wakefulness, and mood elevation. Anorexigenic effect thought to result from direct inhibition of hypothalamic appetite center, as well as mood elevation.

Uses

Narcolepsy, attention deficit disorder in children and adults (hyperkinetic behavioral syndrome, minimal brain dysfunction). Use as short-term adjunct to control exogenous obesity not generally recommended because of its potential for abuse.

Contraindications

Hypersensitivity to sympathomimetic amines; history of drug abuse; severe agitation; hyperthyroidism; diabetes mellitus; moderate to severe hypertension, advanced arteriosclerosis, angina pectoris or other cardiovascular disorders; Gilles de la Tourette disorder; glaucoma; during or within 14 d after treatment with MAOIs; pregnancy (category C); lactation.

Cautious Use

Mild hypertension.

Route & Dosage

Narcolepsy
Adult: PO 5–60 mg/d divided q4–6h in 2–3 doses
Child: PO >12 y, 10 mg/d, may increase by 10 mg at weekly intervals; 6–12 y, 5 mg/d, may increase by 5 mg at weekly intervals

Attention Deficit Disorder
Adult/Adolescent: PO 10 mg extended release once daily in a.m.; may increase by 5–10 mg at weekly intervals if needed to max 30 mg/d.
Child: PO 6 y, 5 mg 1–2 times/d, may increase by 5 mg at weekly intervals (max: 40 mg/d); 3–5 y, 2.5 mg 1–2 times/d, may increase by 2.5 mg at weekly intervals; 10 mg extended release once daily in a.m.; may increase by 5–10 mg at weekly intervals if needed to max of 30 mg/d.

Obesity
Adult: PO 5–10 mg 1 h before meals

Administration

Oral

Give first dose on awakening or early in a.m. when prescribed for narcolepsy.
Give last dose no later than 6 h before patient retires to avoid insomnia.
Ensure that sustained release capsules are not crushed or chewed.
Give drug on an empty stomach 30–60 min before meal to suppress appetite when prescribed for obesity.
Store at 15°–30° C (59°–86° F) unless otherwise directed.

Adverse Effects (≥1%)

Body as a Whole: Allergy, urticaria, sudden death (reported in children with structural cardiac abnormalities). CNS: Irritability, psychosis, restlessness, nervousness, headache, insomnia, weakness, euphoria, dysphoria, drowsiness, trembling, hyperactive reflexes. CV: Palpitation, elevated BP; tachycardia, vasculitis. Urogenital: Impotence & change in libido with high doses. GI: Dry mouth, anorexia, unusual weight loss, nausea, vomiting, diarrhea, or constipation.

Diagnostic Test Interference

Elevations in serum thyroxine (T₄) levels with high amphetamine doses.

Interactions

Drug: Acetazolamide, sodium bicarbonate decrease amphetamine elimination; ammonium chloride, ascorbic acid increase amphetamine elimination; effects of both amphetamine and barbiturate may be antagonized if given together; furazolidone may increase BP effects of amphetamines, and interaction may persist for several weeks after furazolidone is discontinued; guanethidine antagonizes antihypertensive effects; because mao inhibitors, selegiline can precipitate hypertensive 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 amphetamine effects through increased norepinephrine release; beta agonists increase cardiovascular adverse effects.

Pharmacokinetics

Absorption: Rapid. Peak effect: 1–5 h. Duration: Up to 10 h. Distribution: All tissues, especially CNS. Metabolism: In liver. Elimination: Renal; excreted into breast milk. Half-Life: 10–30 h.

Nursing Implications

Assessment & Drug Effects

Monitor for therapeutic effectiveness. Tolerance to the mood-elevating effects commonly occurs within a few weeks. Drug is usually discontinued when tolerance develops. Generally, tolerance does not occur when used for attention deficit disorder or narcolepsy.
Monitor for S&S of toxicity in children. Response to this drug is more variable in children than adults; acute toxicity has occurred over a wide range of dosage.
Monitor for S&S of insomnia or anorexia. Report complaints to physician. Dosage reduction may be required.
Monitor diabetics closely for loss of glycemic control.
Monitor growth in children; drug may be discontinued periodically to allow for normal growth.
Note: Drug's excitatory and euphoric effects are associated with a high abuse potential.

Patient & Family Education

Keep physician informed of clinical response and persistent or bothersome adverse effects. This drug exerts a stimulating effect that masks fatigue; after exhilaration disappears, fatigue and depression are usually greater than before, and a longer period of rest is needed.
Report insomnia or undesired weight loss.
Do not drive or engage in potentially hazardous tasks until response to drug is known.
Rinse mouth frequently with clear water, especially after eating, to relieve mouth dryness; increase fluid intake, if allowed; chew sugarless gum or sourballs.
Note: Meticulous oral hygiene is required because decreased saliva encourages demineralization of tooth surfaces and mucosal erosion. Use of a commercially available oral lubricant, such as Moi-Stir or Xero-Lube, can relieve soft tissue problems and reduce the potential of tooth decay.
Note: Appetite suppression usually lessens within a few weeks and appetite increases; dose increase is not indicated.
Avoid caffeine-containing beverages because caffeine increases amphetamine effects.
Note that drug is usually tapered gradually following prolonged administration of high doses. Abrupt withdrawal may result in lethargy, profound depression, or other psychotic manifestations that may persist for several weeks.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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