Drug Guide
Dextroamphetamine
Classification
Therapeutic: Central Nervous System stimulant, ADHD agent
Pharmacological: Sympathomimetic amine
FDA Approved Indications
- Attention Deficit Hyperactivity Disorder (ADHD)
- Narcolepsy
Mechanism of Action
Dextroamphetamine increases the release of norepinephrine and dopamine in the brain, leading to enhanced neurotransmission, which results in increased alertness, attention, and focus.
Dosage and Administration
Adult: Initial dose typically 12.3 mg once daily in the morning, titrated as needed. Max dose varies based on clinical response.
Pediatric: Starting dose varies by age, generally 5-10 mg daily, titrated to effect; maximum doses depend on patient response.
Geriatric: Use with caution; lower doses recommended due to increased sensitivity and comorbidities.
Renal Impairment: Adjust dose based on severity; close monitoring required.
Hepatic Impairment: Use with caution; no specific dose adjustment established.
Pharmacokinetics
Absorption: Rapidly absorbed from the GI tract.
Distribution: Widely distributed in body tissues, crosses the blood-brain barrier.
Metabolism: Minimal hepatic metabolism; primarily excreted unchanged in urine.
Excretion: Renal excretion, highly pH-dependent.
Half Life: Approximately 3 to 4 hours.
Contraindications
- History of hypersensitivity to amphetamines or other stimulants.
- Advanced arteriosclerosis.
- Symptomatic cardiovascular disease.
- Moderate to severe hypertension.
- Hyperthyroidism.
- History of drug dependence.
- Glaucoma.
Precautions
- Use with caution in patients with a history of mental health disorders, substance abuse, or cardiovascular issues.
- Monitor for signs of exacerbation of psychiatric conditions, such as agitation or psychosis.
- Potential for abuse and dependence.
Adverse Reactions - Common
- Anxiety, restlessness (Common)
- Insomnia (Common)
- Loss of appetite (Common)
- Dry mouth (Common)
Adverse Reactions - Serious
- Cardiovascular risks (hypertension, tachycardia, arrhythmias) (Serious and less common)
- Psychiatric effects (paranoia, hallucinations, new or worsened psychosis) (Serious and less common)
- Potential for abuse, dependence, and addiction (Serious)
Drug-Drug Interactions
- Monoamine oxidase inhibitors (risk of hypertensive crisis)
- Other sympathomimetics (additive effects)
- Serotonergic drugs (risk of serotonin syndrome)
Drug-Food Interactions
- Avoid acidic foods and beverages which may increase the excretion of the drug, reducing efficacy.
Drug-Herb Interactions
- Potential interactions with St. John's Wort and other serotonergic herbs.
Nursing Implications
Assessment: Monitor cardiovascular status, mental health, growth in children, and potential signs of abuse.
Diagnoses:
- Risk of impaired cardiovascular function
- Risk for medication dependence
Implementation: Administer in the morning to reduce insomnia. Monitor blood pressure, heart rate, and mental health.
Evaluation: Assess therapeutic response and side effects regularly.
Patient/Family Teaching
- Take exactly as prescribed. Do not exceed the recommended dose.
- Report any chest pain, palpitations, or mental health changes.
- Avoid alcohol and other CNS depressants.
- Do not abruptly stop medication without consulting provider.
Special Considerations
Black Box Warnings:
- Potential for abuse and dependence.
- Serious cardiovascular events.
Genetic Factors: Variable response based on genetic factors affecting metabolism.
Lab Test Interference: May affect growth measurements in children; monitor accordingly.
Overdose Management
Signs/Symptoms: Restlessness, tremors, hyperreflexia, hallucinations, seizures, rapid heartbeat, hypertension, agitation, panic, hallucinations, diarrhea, fever.
Treatment: Supportive care, activated charcoal if recent ingestion, benzodiazepines for agitation and seizures, cardiovascular support as needed.
Storage and Handling
Storage: Store at room temperature, away from light and moisture.
Stability: Stable under recommended storage conditions.