What are the guidelines for using amphetamines (amphetamine) in treating conditions like Attention Deficit Hyperactivity Disorder (ADHD) and narcolepsy?

Guidelines for Using Amphetamines in ADHD and Narcolepsy

Amphetamines are effective treatments for both ADHD and narcolepsy, with methylphenidate recommended as first-line for ADHD and dextroamphetamine suggested for narcolepsy, though they require careful monitoring due to their potential for abuse and side effects. 1, 2

Indications for Amphetamine Use

ADHD Treatment

• Indicated for moderate to severe ADHD symptoms with impairment in at least two different settings 2
• Methylphenidate is recommended as first-line pharmacological treatment over amphetamines due to its established safety profile 1
• Only patients with documented DSM criteria for ADHD should be considered for stimulant treatment 2

Narcolepsy Treatment

• Dextroamphetamine is suggested for narcolepsy in adults (conditional recommendation) 2
• Methylphenidate is also suggested for narcolepsy in adults (conditional recommendation) 2
• Typical narcolepsy symptoms include excessive sleepiness with recurrent sleep attacks and cataplexy 2

Dosing Guidelines

For ADHD:

• Starting doses:
  • Children 3-5 years: 2.5 mg daily, increased in 2.5 mg increments weekly 3
  • Children 6+ years: 5 mg once or twice daily, increased in 5 mg increments weekly 3
  • Maximum dose rarely exceeds 40 mg per day 3

For Narcolepsy:

• Usual dose: 5-60 mg per day in divided doses 3
• Children 6-12 years: Start with 5 mg daily, increase by 5 mg weekly 3
• Adults (12+ years): Start with 10 mg daily, increase by 10 mg weekly 3
• First dose upon awakening with additional doses at 4-6 hour intervals 3

Contraindications and Precautions

• Absolute contraindications: 2, 1

  • Previous sensitivity to stimulants
  • Glaucoma
  • Symptomatic cardiovascular disease
  • Hyperthyroidism
  • Hypertension
  • Concurrent use of MAOIs
  • History of psychosis or mania

• Special precautions:

  • Pregnancy and breastfeeding (may cause fetal harm based on animal data) 2
  • History of drug dependence (high potential for abuse) 2
  • Cardiovascular conditions (stimulants typically increase heart rate by 1-2 bpm and blood pressure by 1-4 mmHg) 1

Monitoring Requirements

1. Before initiation:

   • Complete psychiatric evaluation including detailed history 2
   • Cardiovascular assessment 1
   • Documentation of target symptoms 2

2. During treatment:

   • Regular monitoring of vital signs, weight, and height (in children) 1
   • Assessment for psychiatric symptoms or tics 1
   • Evaluation of efficacy using standardized rating scales 1

Side Effects and Management

• Common side effects: headache, dry mouth, sweating, loss of appetite, irritability, and insomnia 2
• More serious concerns:
  • Cardiovascular effects (tachycardia, hypertension) 4
  • Potential for abuse (Schedule II controlled substances) 5
  • Peripheral vascular manifestations including vasospastic symptoms 4

Treatment Algorithm

1. For ADHD:

   • First-line: Behavioral interventions with parent training and classroom interventions 1
   • If insufficient response: Add methylphenidate at low dose 1
   • If inadequate response to methylphenidate: Try amphetamine-based medication 1
   • If stimulants ineffective or contraindicated: Consider non-stimulants (atomoxetine, guanfacine, clonidine) 1

2. For Narcolepsy:

   • First-line options include dextroamphetamine or methylphenidate 2
   • Start at low doses and titrate based on response 3
   • Avoid late evening doses due to insomnia 3

Important Clinical Pearls

• Approximately 40% of patients respond to both methylphenidate and amphetamine, while about 40% respond to only one medication class 1
• Amphetamines should be administered at the lowest effective dosage with individualized adjustment 3
• Drug administration should be interrupted occasionally to determine if continued therapy is necessary 3
• Late evening doses should be avoided because of resulting insomnia 3
• Compliance monitoring may be performed through blood and hair analysis in high-risk patients 6

Amphetamines remain valuable treatments for both ADHD and narcolepsy when used appropriately, but their potential for abuse and side effects necessitates careful patient selection, monitoring, and dose adjustment.