What adjustments can be made to the treatment plan for a patient with Attention Deficit Hyperactivity Disorder (ADHD) and Binge Eating Disorder (BED) who experiences increased binge eating with higher doses of their ADHD medication, currently at 70mg and previously at 150mg?

Treatment Adjustment for ADHD with Paradoxical Binge Eating on Higher Stimulant Doses

This patient is experiencing a paradoxical worsening of binge eating with higher stimulant doses, which suggests the current ADHD medication may be exacerbating impulsivity rather than controlling it—you should switch to lisdexamfetamine 50-70 mg daily, which is the only FDA-approved medication for both ADHD and binge eating disorder and has demonstrated efficacy in reducing both conditions simultaneously. 1, 2

Understanding the Clinical Problem

• The patient's worsening binge eating at higher stimulant doses represents a treatment-emergent adverse effect where the medication intended to improve impulse control is paradoxically worsening it 3
• Both ADHD and binge eating disorder share common neurobiological mechanisms involving impulsivity, compulsivity, and deficits in dopaminergic and noradrenergic neurotransmission 3, 4
• The current atomoxetine dose of 150 mg exceeds the FDA maximum of 100 mg daily, which may be contributing to adverse effects rather than therapeutic benefit 5

Immediate Medication Adjustments

First-Line Recommendation: Switch to Lisdexamfetamine

• Initiate lisdexamfetamine 30 mg daily for one week, then increase to 50 mg daily, with potential titration to 70 mg daily based on response 1, 2
• Lisdexamfetamine is the only medication approved by the FDA for both moderate-to-severe binge eating disorder and ADHD, making it uniquely suited for this dual diagnosis 1
• Clinical trials demonstrate that lisdexamfetamine 50-70 mg/day significantly reduces binge eating days per week while simultaneously treating ADHD symptoms 1
• The prodrug formulation provides smooth, extended coverage (12-14 hours) with lower abuse potential compared to immediate-release stimulants 6, 2

Alternative if Lisdexamfetamine is Unavailable

• Reduce atomoxetine to the FDA-approved maximum of 100 mg daily (currently at 150 mg, which exceeds safety limits) 5
• The FDA label explicitly states "there are no data that support increased effectiveness at higher doses" above 100 mg, and the current dose may be causing harm rather than benefit 5
• Atomoxetine requires 4-6 weeks for full therapeutic effect on ADHD symptoms but does not directly treat binge eating disorder 6

Critical Monitoring During Transition

• Assess binge eating frequency weekly using a structured diary or rating scale during the first 4-8 weeks of lisdexamfetamine treatment 1
• Monitor cardiovascular parameters (blood pressure and pulse) at each visit, as both stimulants and atomoxetine can elevate these 6
• Evaluate for common adverse effects including dry mouth, headache, insomnia, and appetite suppression, which are typically mild to moderate in intensity 1
• Track weight changes, as lisdexamfetamine may produce weight loss, which could be beneficial given the association between binge eating disorder and obesity 7, 1

Why the Current Regimen is Failing

• The 70 mg stimulant dose (medication type not specified in question) may be causing rebound effects or excessive dopaminergic stimulation that paradoxically worsens impulse control 3
• Atomoxetine at 150 mg exceeds FDA-approved dosing (maximum 100 mg) and provides no additional benefit while increasing risk of adverse effects 5
• The combination may be creating an imbalanced neurotransmitter profile that exacerbates rather than controls impulsive eating behaviors 3

Pharmacological Rationale for Lisdexamfetamine

• Lisdexamfetamine's efficacy in both conditions stems from its ability to potentiate central noradrenergic and dopaminergic neurotransmission, which reduces impulsivity, compulsivity, and perseveration while increasing cognitive control of eating 3
• The prodrug design provides consistent d-amphetamine delivery throughout the day, avoiding the peaks and troughs that may trigger binge eating episodes 2
• Phase III trials demonstrated marked reduction in binge eating days per week at 12 weeks, with sustained efficacy up to 52 weeks and reduced relapse risk compared to placebo 1

Common Pitfalls to Avoid

• Do not continue escalating the current stimulant dose—the patient has already demonstrated that higher doses worsen binge eating, indicating a dose-response relationship in the wrong direction 3
• Do not maintain atomoxetine at 150 mg—this exceeds FDA maximum dosing and provides no additional therapeutic benefit while increasing adverse effect risk 5
• Do not add appetite suppressants or additional stimulants—this will likely worsen the paradoxical response and increase cardiovascular risk 6
• Do not dismiss the binge eating as a separate issue—the neurobiological overlap between ADHD and binge eating disorder means they must be treated as interconnected conditions 4

Expected Timeline for Improvement

• Lisdexamfetamine produces immediate effects on ADHD symptoms (within days) but requires 4-12 weeks for maximal reduction in binge eating frequency 1, 2
• If no improvement in binge eating is observed after 12 weeks at optimal dose (50-70 mg), consider adding topiramate or behavioral interventions, though lisdexamfetamine monotherapy should be attempted first 7
• Approximately 70-90% of patients respond to catecholaminergic medications when properly dosed, making treatment failure uncommon if lisdexamfetamine is titrated appropriately 8