What are the trade and generic names of stimulant medications and what are their differences?

Stimulant Medications for ADHD: Generic and Trade Names and Their Differences

Stimulant medications for ADHD primarily consist of methylphenidate and amphetamine formulations, which differ in their mechanisms of action, duration, formulations, and side effect profiles. 1

Main Classes of Stimulant Medications

Methylphenidate-Based Stimulants

• Mechanism of Action: Inhibits dopamine and norepinephrine transporters, acts as serotonin type 1A receptor agonist, and redistributes vesicular monoamine transporter 2 1
• Generic/Trade Names:
  • Immediate-release: Methylphenidate (Ritalin)
  • Extended-release: Concerta (OROS technology), Ritalin LA, Metadate CD, Quillivant XR (liquid), Daytrana (transdermal patch)
  • Starting dose: 5 mg twice daily (immediate-release), 10 mg once daily (extended-release) 2

Amphetamine-Based Stimulants

• Mechanism of Action: Inhibits dopamine and norepinephrine transporters, vesicular monoamine transporter 2, and monoamine oxidase activity 1
• Generic/Trade Names:
  • Mixed amphetamine salts: Adderall (immediate-release), Adderall XR (extended-release)
  • Dextroamphetamine: Dexedrine, ProCentra, Zenzedi
  • Lisdexamfetamine dimesylate: Vyvanse (prodrug)
  • Starting dose: 5-10 mg daily 2

Key Differences Between Stimulant Types

1. Pharmacological Differences

• Methylphenidate vs. Amphetamine Response: Response is idiosyncratic, with approximately 40% of patients responding to both medications and about 40% responding to only one 1
• Effect Size: Both have robust effect sizes around 1.0 for treating ADHD symptoms, significantly higher than non-stimulants (0.7) 1

2. Duration of Action

• Short-acting formulations: 3-4 hours of symptom control, requiring multiple daily doses 1, 2
• Long-acting formulations: 8-12+ hours of coverage, allowing once-daily dosing 1, 3
• Delivery systems: Different release profiles affect how quickly peak levels are attained and decline 1

3. Formulation Differences

• Immediate-release: Faster onset but shorter duration, more flexibility with dosing 1
• Extended-release: Better medication adherence, lower risk of rebound effects 1
• Novel delivery systems: Chewable tablets, liquid formulations, transdermal patches 1, 3
• Prodrug (lisdexamfetamine): Converted to active form in the bloodstream, potentially reducing abuse potential 3

4. Side Effect Profiles

• Common side effects for both classes: Decreased appetite, sleep disturbances, increased blood pressure/heart rate, headaches, irritability, stomach pain 1
• Growth effects: Both can cause small but statistically significant reductions in height and weight gain 1
• Cardiovascular effects: Both cause small increases in blood pressure and heart rate 1

Clinical Considerations When Choosing Between Stimulants

Individual Response Patterns

• ADHD subtype does not predict response to a specific stimulant 1
• Patient's prior response to stimulants should guide medication selection
• If one stimulant class is ineffective or causes side effects, trying the other class is recommended 1

Formulation Selection Based on Patient Needs

• Consider daily schedule: School/work requirements may determine need for longer coverage
• Consider abuse potential: Prodrugs and extended-release formulations may have lower abuse potential 4
• Consider administration challenges: Some patients may benefit from liquid, chewable, or patch formulations 3

Drug Interactions

• Acidifying agents: Decrease absorption and increase urinary excretion of amphetamines 5, 6
• Alkalinizing agents: Increase absorption and decrease urinary excretion of amphetamines 5, 6
• MAO inhibitors: Can cause dangerous interactions with amphetamines 5, 6
• Serotonergic drugs: Risk of serotonin syndrome when combined with amphetamines 6

Monitoring and Safety Considerations

• Regular monitoring of blood pressure, heart rate, weight, and growth parameters is essential 1, 2
• Cardiovascular assessment before starting stimulants is recommended, especially in patients with preexisting conditions 1
• Monitoring for emergence or exacerbation of tics, anxiety, or mood symptoms 1, 5

Stimulant selection should be based on individual patient factors, including age, comorbidities, prior medication response, daily schedule requirements, and side effect profile. If one class of stimulant is ineffective or poorly tolerated, switching to the other class is a reasonable approach before considering non-stimulant options.