What interventions are recommended for a patient with Attention Deficit Hyperactivity Disorder (ADHD) who experiences impaired focus after increasing their dose from 5 mg of dextroamphetamine (amphetamine) to 10 mg of amphetamine salts?

Paradoxical Worsening of Focus with Higher Amphetamine Dose

Reduce the amphetamine salts dose back to 5 mg (or equivalent dextroamphetamine dose) immediately, as this patient is experiencing a paradoxical response to dose escalation—a well-recognized phenomenon where excessive stimulant dosing can impair rather than improve attention. 1

Understanding the Paradoxical Response

This patient's worsening focus at 10 mg represents a dose-related adverse effect rather than treatment failure. The American Academy of Child and Adolescent Psychiatry explicitly recognizes that not all patients benefit from higher doses, and the optimal dose must be determined by systematic assessment of both therapeutic effects and side effects at each dose level. 1

Key Mechanism

• Overstimulation can paradoxically worsen attention and focus, causing symptoms that may include increased distractibility, agitation, or cognitive inflexibility. 1
• The therapeutic window for amphetamines varies significantly between individuals and is not weight-based or predictable. 2

Immediate Management Steps

Step 1: Dose Reduction

• Return to the 5 mg dose that was previously effective (whether dextroamphetamine or amphetamine salts equivalent). 1
• Maintain this dose for at least 1 week while systematically assessing symptom control using standardized ADHD rating scales. 1, 2

Step 2: Systematic Assessment

• Obtain ADHD rating scales to objectively measure symptom severity at the lower dose. 1
• Evaluate both therapeutic effects (attention, focus, task completion) and side effects (appetite, sleep, mood, cardiovascular symptoms) before considering any further adjustments. 1, 2
• Monitor vital signs including blood pressure and pulse. 1, 2

Step 3: Consider Alternative Titration Strategies

If 5 mg provides inadequate symptom control after reassessment:

• Try intermediate dosing (7.5 mg) rather than jumping to 10 mg, as smaller incremental increases may identify the optimal therapeutic dose. 1
• Consider divided dosing (e.g., 5 mg twice daily) rather than a single higher dose, which may provide better symptom coverage without overstimulation. 1
• Allow at least 1 week between dose adjustments to properly evaluate response. 1, 2

Alternative Approaches if Dose Optimization Fails

Switch Stimulant Class

• Consider switching to methylphenidate if amphetamines continue to cause problems even at lower doses, as more than 90% of patients respond to one of the two stimulant classes when both are properly tried. 2
• Methylphenidate has a different mechanism and pharmacokinetic profile that some patients tolerate better. 3

Add Non-Stimulant Medication

• If the patient is a partial responder to low-dose amphetamines, adding atomoxetine or guanfacine extended-release may provide additional benefit without requiring higher stimulant doses. 2, 4

Critical Pitfalls to Avoid

• Do not continue escalating the dose assuming "more is better"—this patient has already demonstrated that higher doses worsen function. 1
• Do not assume treatment failure—the patient responded well to 5 mg, indicating stimulants are appropriate but the dose was simply too high. 1
• Do not switch medications prematurely without first optimizing the current regimen at the effective lower dose. 1, 4
• Avoid fixed dose-escalation protocols that ignore individual response patterns—titration must be guided by systematic assessment of both benefits and side effects at each dose level. 1, 2

Monitoring During Dose Adjustment

• Assess symptom control and side effects at least weekly during the dose adjustment period. 1, 2
• Use standardized rating scales rather than subjective impressions alone. 1
• Monitor cardiovascular parameters (blood pressure, pulse) with each dose change. 1, 2
• Evaluate sleep quality, appetite, and mood as these commonly reflect overstimulation. 1

Long-Term Considerations

Once the optimal dose is identified (likely 5 mg or an intermediate dose):

• Maintain monthly follow-up until symptoms are fully stabilized. 2
• Reassess periodically for continued efficacy, as tolerance can develop in some patients. 1
• The effective dose may remain stable long-term, with studies showing sustained benefit at optimized doses for up to 24 months. 5