Is continuing lamotrigine 200 mg daily and increasing atomoxetine (Strattera) from 40 mg appropriate for a patient with anorexia nervosa, attention‑deficit/hyperactivity disorder, and obsessive‑compulsive disorder who exhibits ritualistic compulsions and was recently discharged against medical advice after a brief inpatient admission?

This treatment plan is inadequate and potentially harmful—the patient requires immediate eating disorder-focused psychotherapy as the primary intervention, with careful medication reassessment and close monitoring for cardiac safety given the combination of anorexia nervosa, recent AMA discharge, and current psychotropic medications 1.

Critical Safety Concerns

Obtain an ECG immediately. Both lamotrigine and atomoxetine can prolong QTc intervals, and this patient with restrictive eating disorder is at high risk for cardiac complications 1. The APA guidelines explicitly recommend ECG monitoring in patients with restrictive eating disorders taking medications known to affect cardiac conduction 1.

The atomoxetine dose of 40 mg is subtherapeutic for ADHD and increasing it in the context of active anorexia nervosa raises serious concerns 2, 3. The FDA label warns that atomoxetine can cause:

• Decreased appetite and weight loss (common side effects)
• Cardiovascular effects including increased heart rate and blood pressure
• Potential for severe liver damage 2

In a malnourished patient who recently left inpatient treatment AMA, these risks are amplified. While one case report suggests atomoxetine reduced binge/purge symptoms in AN binge/purge type 4, this patient has ritualistic OCD behaviors, not binge/purge pathology, making this evidence non-applicable.

What This Patient Actually Needs

Primary treatment must be eating disorder-focused psychotherapy 1. The 2023 APA Eating Disorders Guideline (1B recommendation) states that adults with anorexia nervosa require psychotherapy that includes normalizing eating behaviors, restoring weight, and addressing psychological aspects like fear of weight gain 1. If this is an adolescent or emerging adult with involved caregivers, family-based treatment is recommended 1.

There is no evidence supporting lamotrigine or atomoxetine as primary treatments for anorexia nervosa 5. The most recent evidence (2025) confirms that except for moderate evidence supporting olanzapine for weight gain, there is no efficacy data for psychopharmacotherapy in AN 5.

Addressing the Comorbidities

For OCD:

The ritualistic behaviors (dressing sequence, handwashing, food organization) causing marked distress represent true OCD pathology. However, lamotrigine at 200 mg may have some benefit for OCD as augmentation 6, 7. A 2016 randomized controlled trial showed lamotrigine 100 mg augmentation of SSRIs reduced Y-BOCS scores in treatment-resistant OCD 7. Case reports support lamotrigine augmentation in severe, long-term treatment-resistant OCD 6.

The problem: This patient is not on an SSRI. Lamotrigine was studied as augmentation to serotonin reuptake inhibitors, not as monotherapy. Consider adding an SSRI (fluoxetine 60 mg is specifically recommended for bulimia nervosa per APA guidelines, though evidence for AN is limited) 1.

For ADHD:

Atomoxetine 40 mg is underdosed 3. The target dose for adults is 80 mg/day, with maximum of 100 mg/day 2. However, real-world data shows average dosing around 60 mg/day, contributing to poor outcomes 3.

Critical decision point: Increasing atomoxetine in active anorexia nervosa is dangerous. The FDA label explicitly warns about appetite suppression and weight loss 2. Recent 2026 data suggests stimulants may be used cautiously in patients with history of AN (not active AN), with appetite suppression occurring but not necessarily exacerbating AN pathology 8. However, this patient has active anorexia nervosa with recent hospitalization and AMA discharge.

Recommended Treatment Algorithm

1. Immediate actions:

   • Obtain ECG to assess QTc interval 1
   • Check vital signs including orthostatic measurements, weight, BMI 1
   • Order CBC and comprehensive metabolic panel including electrolytes, liver enzymes, renal function 1

2. If cardiac/medical instability detected:

   • Consider hospitalization (patient has history of leaving AMA—address barriers to treatment engagement)
   • Hold medication increases until medically stable

3. If medically stable:

   • Continue lamotrigine 200 mg (may help OCD, appears safe in eating disorders based on limited data 9)
   • Hold atomoxetine increase—40 mg is insufficient for ADHD but increasing risks worsening malnutrition 2, 3
   • Add SSRI (fluoxetine 20-60 mg) for OCD augmentation 1, 7
   • Initiate eating disorder-focused psychotherapy immediately as primary treatment 1

4. After weight restoration and eating normalization:

   • Reassess ADHD symptoms (some may improve with nutritional rehabilitation)
   • If ADHD remains impairing, cautiously titrate atomoxetine to 80 mg target dose with close monitoring of weight, appetite, vital signs 2

5. Establish multidisciplinary care:

   • Psychiatrist for medication management
   • Therapist for eating disorder-focused psychotherapy
   • Dietitian for nutritional rehabilitation
   • Primary care for medical monitoring 1

Common Pitfalls to Avoid

Do not prioritize ADHD/OCD medication optimization over eating disorder treatment. The anorexia nervosa has the highest mortality risk and requires immediate, intensive intervention 5. The recent AMA discharge signals high risk for treatment dropout and medical deterioration.

Do not assume the OCD behaviors are purely eating disorder-related. This patient has true comorbid OCD requiring specific treatment, but the eating disorder must be addressed first as it poses the greatest mortality risk 10, 5.

Do not increase appetite-suppressing medications in active anorexia nervosa. While atomoxetine may theoretically help impulsivity, the FDA warnings about appetite suppression and weight loss make dose escalation contraindicated until weight restoration occurs 2.