What are the uses, dosing, and precautions for dextroamphetamine in patients with attention deficit hyperactivity disorder (ADHD) or narcolepsy, particularly those with a history of cardiovascular disease or high blood pressure?

Dextroamphetamine: Clinical Uses, Dosing, and Cardiovascular Precautions

Dextroamphetamine is FDA-approved for ADHD and narcolepsy, with typical dosing of 5-60 mg daily in divided doses, but requires careful cardiovascular screening before initiation, particularly in patients with pre-existing heart disease or hypertension, as it consistently increases blood pressure by approximately 2 mmHg and heart rate by 3-4 beats per minute. 1, 2

FDA-Approved Indications

ADHD Treatment

• Approved for children aged 3 years and older, adolescents, and adults with ADHD as part of a comprehensive treatment program including psychological, educational, and social interventions 1
• Start with 2.5 mg daily in children 3-5 years old, increasing by 2.5 mg weekly until optimal response 1
• For children ≥6 years, begin with 5 mg once or twice daily, increasing by 5 mg weekly as needed 1
• Maximum dose rarely exceeds 40 mg/day in pediatric patients 1
• Adults require complete psychiatric evaluation with documentation of childhood-onset symptoms before treatment 3

Narcolepsy Management

• Dextroamphetamine at 60 mg daily effectively reduces excessive daytime sleepiness and cataplexy in adults with narcolepsy 3, 4
• Initial dosing: 5 mg daily for ages 6-12 years, increasing by 5 mg weekly; 10 mg daily for patients ≥12 years, increasing by 10 mg weekly 1
• Combine long-acting formulations (Dexedrine Spansule) with immediate-release preparations for flexible dosing and breakthrough symptom control 4
• Give first dose upon awakening, with additional doses at 4-6 hour intervals; avoid late evening doses due to insomnia 1

Cardiovascular Screening and Monitoring Requirements

Pre-Treatment Assessment

Before initiating dextroamphetamine, assess for cardiac disease through detailed personal and family history of sudden death or ventricular arrhythmia, plus physical examination 1, 5

Critical screening elements include:

• Personal history of structural cardiac abnormalities, arrhythmias, coronary artery disease, or cardiomyopathy 5, 6
• Family history of sudden cardiac death or serious arrhythmias 1, 6
• Baseline blood pressure and heart rate measurement 2, 6

Cardiovascular Effects

• Amphetamines increase systolic blood pressure by 1.93 mmHg and diastolic blood pressure by 1.84 mmHg, with heart rate elevation of 3.71 beats per minute—effects that persist with long-term use 2
• These changes are statistically significant and clinically relevant for patients with pre-existing cardiovascular disease 2
• The risk of serious cardiovascular events including sudden cardiac death remains extremely low in properly screened patients without underlying cardiac disease 5, 6

High-Risk Populations Requiring Cardiology Consultation

• Patients with known structural cardiac abnormalities 5, 6
• History of exercise-related syncope or chest pain 6
• Family history of sudden unexplained death before age 50 6
• Pre-existing hypertension or tachycardia 2, 6

Exercise great caution when prescribing stimulants to patients of any age with personal or family history of cardiovascular disease or other known cardiac risk factors 5

Dosing Administration and Titration

Timing and Schedule

• Administer first dose upon awakening to minimize insomnia 1
• Space additional doses 4-6 hours apart 1
• Avoid late evening administration due to sleep disruption 1

Dose Optimization

• Titrate to the lowest effective dose, increasing gradually at weekly intervals until optimal symptom control is achieved 1
• If bothersome adverse effects appear (insomnia, anorexia, irritability), reduce the dose 1
• Periodically interrupt treatment to determine if behavioral symptoms recur and continued therapy remains necessary 1

Critical Safety Warnings and Contraindications

Abuse and Dependence Risk

• Dextroamphetamine is a DEA Schedule II controlled substance with high potential for abuse and dependence 4, 7
• Prolonged administration may lead to psychological dependence 7
• Regular monitoring for signs of tolerance, abuse behaviors, and dose escalation is essential 4

Pregnancy and Reproductive Risks

• Amphetamines cross the placental barrier and may cause fetal harm based on animal data 7
• Possible increased risk for gastroschisis and preeclampsia has been reported 7
• Continued use in the second half of pregnancy may increase preterm birth risk 7
• Monitor infants for irritability, insomnia, and feeding difficulties if maternal amphetamine use occurred during pregnancy 7
• Consider non-pharmacological ADHD interventions during pregnancy 7

Common Adverse Effects

• Appetite suppression and weight loss (particularly concerning in pediatric patients requiring close growth monitoring) 7
• Insomnia, nervousness, and irritability 4
• Sweatiness and edginess 4
• Headache and dry mouth 3
• Withdrawal rate due to adverse effects is 2.69 times higher than placebo, with an absolute risk increase of 4.3% 2

Overdose Presentation

Clinical signs of toxicity include hyperactivity, hyperthermia, tachycardia, tachypnea, mydriasis, tremors, and seizures 8

Monitoring During Treatment

Ongoing Assessment

• Regular blood pressure and heart rate monitoring 2, 6
• Growth parameters in pediatric patients (height and weight) 7
• Signs of stimulant tolerance requiring dose adjustments 4
• Emergence of tics or Tourette's syndrome symptoms 1
• Cardiovascular symptoms (chest pain, syncope, palpitations) 6

Treatment Efficacy

• Both girls and boys respond equally well to stimulant medications for ADHD 3
• Medication effects persist over 24 months without diminution of efficacy 3
• Response occurs across symptom domains, with differential effects on behavior versus attention 3

Alternative Medications

For patients with cardiovascular contraindications or intolerance:

• Methylphenidate (alternative stimulant for narcolepsy and ADHD) 3, 4
• Atomoxetine (non-stimulant for ADHD with similar but milder cardiovascular effects) 5, 6
• Guanfacine-XR or clonidine-XR (α-2 adrenergic agonists that may decrease blood pressure and heart rate) 6

Special Clinical Situations

Medically Ill Patients

• Use approximately one-half the standard ADHD starting dose for apathy or depression in medically ill patients, with slow titration and careful adverse effect monitoring 3
• Evidence supports use in cancer patients, post-stroke patients, and those with opioid-induced sedation 3

Comorbid Conditions

• ADHD with anxiety disorders, oppositional defiant disorder, conduct disorder, or learning disabilities can be treated with stimulants 3
• Comorbid conditions do not affect stimulant response rates 3