dextroamphetamine

(dex-troe-am-fet-a-meen)

Dexedrine, Dextrostat

Classification
Therapeutic: central nervous system stimulants
Pharmacologic: amphetamines

Schedule II

Pregnancy Category C

Copyright © 2007 by F.A. Davis Company

Indications

Narcolepsy. Adjunct management of ADHD. Unlabelled Uses: Exogenous obesity.

Action

Produces CNS stimulation by releasing norepinephrine from nerve endings. Pharmacologic effects: Therapeutic Effects: Increased motor activity and mental alertness and decreased fatigue in narcoleptic patients. Increased attention span in ADHD.

Pharmokinetics

Absorption: Well absorbed
Distribution: Widely distributed; high concentrations in brain and CSF. Crosses the placenta; enters breast milk; potentially embryotoxic
Metabolism and Excretion: Some metabolism by the liver. Urinary excretion is pH-dependent. Alkaline urine promotes reabsorption and prolongs action
Half-life: 10–12 hr (6.8 hr in children)

TIME/ACTION PROFILE (CNS stimulation)
ROUTE ONSET PEAK DURATION
PO 1–2 hr 3 hr 2–10 hr
PO-ER unknown unknown up to 24 hr

Contraindications/Precautions

Contraindicated in: Pregnancy or lactation. Hyperexcitable states, including hyperthyroidism. Psychotic personalities. Suicidal or homicidal tendencies. Glaucoma. Some products contain tartrazine and should be avoided in patients with known hypersensitivity.
Use Cautiously in: Cardiovascular disease. Hypertension. Diabetes mellitus. History of substance abuse. Geri: Appears on Beers list. Elderly are at increased risk for cardiovascular side effects. Debilitated patients. Continual use (may produce psychological dependence or physical addiction).

Adverse Reactions/Side Effects*

*CAPITALS indicate life threatening; underlines indicate most frequent.

CNS: hyperactivity, insomnia, restlessness, tremor, depression, dizziness, headache, irritability.
CV: palpitations, tachycardia, arrhythmias, hypertension.
GI: anorexia, constipation, cramps, diarrhea, dry mouth, metallic taste, nausea, vomiting.
GU: impotence, increased libido.
Derm: urticaria.
Misc: physical dependence, psychological dependence.

Interactions

Drug–Drug: ↑ adrenergic effects with other adrenergics. Use with MAO inhibitors can result in hypertensive crisis. Alkalinizing the urine ( sodium bicarbonate, acetazolamide) prolongs effect. Acidification of urine ( ammonium chloride, large doses of ascorbic acid) ↓ effect. Phenothiazines may decrease the effect of dextroamphetamine. May antagonize the response to antihypertensives. ↑ risk of cardiovascular side effects with beta blockers or tricyclic antidepressants.
Drug–Natural: St. John's Wort may increase serious side effects, concurrent use is not recommended. Use with caffeine-containing herbs (guarana, tea, coffee) ↑ stimulant effect. St. John's Wort may increase serious side effects, concurrent use is not recommended.

Route/Dosage

Attention-Deficit Hyperactivity Disorder

PO (Adults): 5–40 mg/day in divided doses. Sustained-release capsules should not be used as initial therapy.
PO (Children ³6 yr): 5 mg 1–2 times daily, increase by 5 mg daily at weekly intervals (maximum: 40 mg/day). Sustained-release capsules should not be used as initial therapy.
PO (Children 3–5 yr): 2.5 mg/day, increase by 2.5 mg daily at weekly intervals (maximum: 40 mg/day).

Narcolepsy

PO (Adults): 5–60 mg/day single dose or in divided doses. Sustained-release capsules should not be used as initial therapy.
PO (Children ³12 yr): 10 mg/day, increase by 10 mg/day at weekly intervals until response is obtained 60 mg is reached.
PO (Children 6–12 yr): 5 mg/day, increase by 5 mg/day at weekly intervals until response is obtained or 60 mg is reached.

Exogenous obesity

PO (Adults and Children >12 yr): 5–30 mg/day in divided doses of 5–10 mg given 30–60 min before meals.

Availability

Tablets: 5 mg Cost: 5 mg $35.23/100. Sustained-release capsules: 5 mg, 10 mg, 15 mg.

NURSING IMPLICATIONS

Assessment Potential Nursing Diagnoses Implementation Patient/Family Teaching Evaluation/Desired Outcomes