Dexedrine (Dextroamphetamine) Dosing, Contraindications, and Monitoring
Start dextroamphetamine at 2.5 mg once or twice daily (morning and noon), titrate by 2.5-5 mg weekly increments until optimal response, with a maximum of 40 mg/day for ADHD and 60 mg/day for narcolepsy. 1, 2
Dosing Guidelines
Children and Adolescents (ADHD)
- Starting dose: 2.5 mg once or twice daily (after breakfast and lunch) 1
- Titration: Increase by 2.5-5 mg weekly based on response and tolerability 1
- Maximum dose: 40 mg/day total (PDR recommendation) 1
- Weight-based considerations: Children <25 kg should not receive single doses >10 mg 1
- Extended-release (Spansule): Not recommended for children <6 years; can be used for once-daily dosing by adding morning and noon immediate-release doses 2
Adults (ADHD)
- Starting dose: 5 mg once or twice daily 1, 3
- Titration: Increase by 5-10 mg weekly 1
- Maximum dose: Generally 40 mg/day, though some adults may require up to 0.9 mg/kg/day with careful documentation 1
Narcolepsy
- Ages 6-12: Start 5 mg daily, increase by 5 mg weekly 2
- Ages ≥12 and adults: Start 10 mg daily, increase by 10 mg weekly 2
- Maximum dose: 60 mg/day 2
Preschool Children (Ages 4-5)
Dextroamphetamine is NOT recommended as first-line for preschool-aged children despite FDA approval. 4, 5 Although dextroamphetamine is the only stimulant FDA-approved for children <6 years, this approval predates current rigorous standards. Methylphenidate has stronger evidence in this age group. If dextroamphetamine is used, start at lower doses with slower titration due to slower metabolism 4.
Contraindications
Absolute Contraindications 2
- Hypersensitivity to amphetamine or any component (risk of angioedema, anaphylaxis)
- MAOI use within 14 days (including linezolid, IV methylene blue) due to hypertensive crisis risk
- Advanced arteriosclerosis
- Symptomatic cardiovascular disease
- Moderate to severe hypertension
- Hyperthyroidism
- Glaucoma
- Agitated states
- History of drug abuse
Special Populations
- Pregnancy: May cause fetal harm based on animal data; human data insufficient 6, 3
- Breastfeeding: Hale lactation risk L3; monitor infant for irritability, insomnia, feeding difficulty 3
- Substance abuse history: Assess carefully; consider non-stimulant alternatives in adolescents 4
Monitoring Recommendations
Baseline Assessment 1
- Cardiovascular: Detailed personal and family history of sudden death, ventricular arrhythmia, cardiac disease; physical examination
- Blood pressure and pulse
- Height and weight
- Tic disorders: Family history and clinical evaluation for motor/verbal tics or Tourette's syndrome
- Psychiatric: Screen for psychosis, mania, bipolar disorder, substance abuse (especially adolescents)
During Titration (Weekly) 1
- Symptom assessment: ADHD rating scales from parents and teachers (children) or self-report (adults)
- Side effects: Systematically assess insomnia, anorexia, headaches, social withdrawal, tics, weight loss
- Contact: Office visit or phone contact acceptable for weeks 2-4
Maintenance Monitoring
Children and Adolescents 1:
- Vital signs: Blood pressure, pulse, height, weight at each visit during titration
- Annual physical examination with vital signs
- Weight: At each visit to objectively monitor appetite suppression
Adults 1:
- Blood pressure and pulse: Quarterly by treating or primary care physician
- Signs of tolerance: Monitor if using higher doses
- Cardiovascular symptoms: Screen for palpitations, chest pain, dyspnea
Side Effect Management
Common side effects (more problematic than methylphenidate due to longer half-life) 1, 7:
- Appetite suppression: Most consistent finding; monitor weight 7
- Insomnia: More severe than methylphenidate; avoid late-day dosing 1, 7
- Emotional symptoms: Irritability, crying, anxiousness, sadness more severe with dextroamphetamine than methylphenidate 7
- Cardiovascular: Increases systolic BP by ~2 mmHg, diastolic BP by ~2 mmHg, heart rate by ~4 bpm 8
Serious adverse effects 9:
- Psychosis/mania risk: Dose-dependent; high doses (>30 mg dextroamphetamine equivalents) associated with 5.28-fold increased odds 9
- Growth attenuation: More pronounced in children started younger and those requiring higher doses 10
- Withdrawal rate: 2.69 times higher than placebo due to adverse effects 8
Clinical Pearls and Pitfalls
Dosing Strategy
- Dextroamphetamine may require only once-daily dosing in some children due to longer duration of action 1
- Spansule formulation: Provides 6-8 hours of action; can combine with immediate-release for flexible dosing 1
- "Forced titration" option: Trial all four doses (2.5,7.5,10 mg) for one week each, then select optimal dose based on efficacy and side effects 1
When to Switch Medications
- If no response at maximum recommended dose, switch to alternative stimulant rather than exceeding limits 1
- ~70% respond to either dextroamphetamine or methylphenidate alone; ~90% respond if both tried 1
- Methylphenidate may be better tolerated with fewer appetite and sleep problems 1
High-Dose Considerations
- Doses may rarely exceed PDR limits (40 mg/day) with careful documentation 1
- Document: Symptoms uncontrolled at lower doses, absence of side effects (weight loss, BP increase, agitation), no signs of tolerance 1
- Growth attenuation primarily occurs before reaching high-dose range 10