Nurses Compass
Drug Guide
Amphetamine
Classification
Therapeutic: Central nervous system stimulants for ADHD and narcolepsy
Pharmacological: Amphetamine is a sympathomimetic amine with stimulant properties
FDA Approved Indications
- Attention deficit hyperactivity disorder (ADHD)
- Narcolepsy
Mechanism of Action
Amphetamine increases the release of norepinephrine and dopamine in the brain by reversing transporter activity and inhibiting reuptake, leading to increased synaptic concentrations and stimulant effects.
Dosage and Administration
Adult: Dosing varies; typically, starting dose is 10-20 mg once or twice daily, titrated based on response and tolerability.
Pediatric: For children 6 years and older, dosing usually starts at 5-10 mg once or twice daily, adjusted as needed.
Geriatric: Use with caution; dosing should start low and titrated carefully owing to potential comorbidities.
Renal Impairment: Use with caution; consider dose adjustments and close monitoring.
Hepatic Impairment: No specific adjustment established; use caution.
Pharmacokinetics
Absorption: Well absorbed orally; peak plasma levels achieved in about 3 hours.
Distribution: Widely distributed, crosses the blood-brain barrier and placental barrier.
Metabolism: Primarily hepatic; minimal metabolism.
Excretion: Renal, with 30-40% excreted unchanged in urine.
Half Life: Approximately 9-14 hours, varies with urinary pH.
Contraindications
- History of hypersensitivity to amphetamines or other stimulants.
- Advanced arteriosclerosis.
- History of drug abuse.
- Within 14 days of MAOI use.
- Significant unmanaged hypertension.
Precautions
- Caution in patients with cardiovascular disease, hypertension, hyperthyroidism, glaucoma, or history of drug dependence.
Adverse Reactions - Common
- Insomnia (Common)
- Dry mouth (Common)
- Anorexia, weight loss (Common)
- Anxiety, agitation (Common)
Adverse Reactions - Serious
- Cardiovascular events such as hypertension, tachycardia, or arrhythmias (Serious but less common)
- Dependency or abuse potential (Serious risk)
Drug-Drug Interactions
- Monoamine oxidase inhibitors (MAOIs), may cause hypertensive crisis
- Other CNS stimulants increase effects
Drug-Food Interactions
- Avoid excessive caffeine intake which can enhance adverse effects
Drug-Herb Interactions
N/ANursing Implications
Assessment: Monitor cardiovascular status, growth in children, and behavioral effects.
Diagnoses:
- Risk for hypertension
- Impaired sleep pattern
- Potential for substance abuse
Implementation: Administer as prescribed, typically in the morning to minimize insomnia. Monitor for adverse effects.
Evaluation: Assess changes in attention, hyperactivity, and side effects. Adjust dosage accordingly.
Patient/Family Teaching
- Take medication exactly as prescribed.
- Monitor for signs of cardiovascular problems, loss of appetite, or sleep disturbances.
- Avoid caffeine and other stimulants.
- Report any signs of abnormal behavior or side effects to healthcare provider.
Special Considerations
Black Box Warnings:
- Potential for abuse and dependence.
- Serious cardiovascular events.
Genetic Factors: Metabolism influenced by CYP2D6 enzyme activity.
Lab Test Interference: May affect growth parameters in children; impact on blood pressure readings.
Overdose Management
Signs/Symptoms: Elevated body temperature, hallucinations, agitation, hypertension, tachycardia, seizures.
Treatment: Supportive care, benzodiazepines for agitation or seizures, active cooling, and cardiovascular support as needed.
Storage and Handling
Storage: Store at room temperature, away from light and moisture.
Stability: Stable under recommended conditions.