What is the appropriate medical assessment and treatment plan for a patient with a suspected eating disorder?

Medical Assessment and Treatment of Eating Disorders

Initial Medical Assessment

All patients with suspected eating disorders require immediate vital sign measurement including temperature, resting heart rate, blood pressure, and orthostatic changes (pulse and blood pressure), as these parameters identify cardiovascular instability that may necessitate hospitalization. 1

Essential Physical Examination Components

• Document height, weight, and BMI (or percent median BMI, BMI percentile, or BMI Z-score for children and adolescents) at the initial visit. 1
• Examine for physical signs of malnutrition or purging behaviors, specifically Russell's sign (calluses on knuckles from self-induced vomiting), parotid gland enlargement, and dental erosion. 1
• Assess for bradycardia (heart rate <40–50 bpm), which indicates severe cardiovascular compromise and potential need for hospitalization. 2

Required Laboratory Testing

• Obtain a complete blood count to detect anemia, leukopenia, and other hematologic abnormalities associated with malnutrition. 1
• Order a comprehensive metabolic panel including electrolytes (sodium, potassium, chloride, bicarbonate), liver enzymes, and renal function tests (BUN, creatinine) to identify hyponatremia, hypokalemia, hypochloremia, metabolic alkalosis, and hepatic or renal dysfunction. 1
• Perform an electrocardiogram in all patients with restrictive eating disorders or severe purging behaviors to assess QTc interval, as prolongation increases risk of sudden cardiac death. 1
• Measure thyroid function tests (TSH and free T4) in patients with oligomenorrhea or amenorrhea. 1
• Consider 25-hydroxyvitamin D levels if low bone mineral density or bone stress injury is suspected. 1

Critical caveat: Normal laboratory values do NOT exclude serious illness—approximately 60% of patients with anorexia nervosa have normal routine laboratory results despite severe malnutrition. 1

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Disorder-Specific Treatment Approaches

Anorexia Nervosa

Adolescents and Emerging Adults

Family-based treatment (FBT) is the first-line psychotherapy for adolescents and emerging adults with anorexia nervosa who have an involved caregiver, achieving a 48.6% remission rate at 6–12 months versus 34.3% with individual therapy alone. 1, 2

• FBT involves active parental supervision of meals and collaborative meal planning as critical therapeutic components. 2
• Parental alignment with the treatment plan is essential; denial or disagreement worsens outcomes. 2

Adults

• Adults with anorexia nervosa should receive eating disorder-focused psychotherapy that normalizes eating behaviors, restores weight, and addresses psychological aspects including fear of weight gain and body image disturbance. 1
• No FDA-approved or guideline-recommended medication exists for anorexia nervosa; treatment relies exclusively on psychotherapy and nutritional rehabilitation. 1

Nutritional Rehabilitation

• Set individualized goals for weekly weight gain (typically 2.2 to 4.4 lb per week to stabilize cardiovascular health) and establish a target weight for all patients requiring nutritional rehabilitation. 1, 3
• Initiate slow, cautious refeeding with phosphorus supplementation to prevent refeeding syndrome, which can be fatal in severely malnourished patients. 1
• Nutrition may need to be provided via nasogastric tube or intravenously if oral intake is insufficient. 1

Bulimia Nervosa

Adults

Adults with bulimia nervosa should receive eating disorder-focused cognitive-behavioral therapy (CBT) combined with fluoxetine 60 mg daily—the therapeutic dose is 60 mg, which is higher than typical antidepressant dosing. 1, 4

• Fluoxetine may be started initially or added if there is minimal response to psychotherapy alone by 6 weeks. 1
• Reassess treatment response at 6 weeks; if response is minimal, optimize psychotherapy or adjust medication dosage. 1

Adolescents and Emerging Adults

• Family-based treatment should be offered to adolescents and emerging adults with bulimia nervosa who have an involved caregiver. 1

Binge-Eating Disorder

Patients with binge-eating disorder should receive eating disorder-focused cognitive-behavioral therapy or interpersonal therapy, delivered in either individual or group formats. 1

Pharmacotherapy Options

• For adults who prefer medication or have not responded to psychotherapy alone, prescribe either an antidepressant (e.g., fluoxetine) or lisdexamfetamine. 1, 5
• Lisdexamfetamine (50 or 70 mg/day) demonstrated statistically significant reduction in binge days per week compared to placebo in two 12-week trials. 5

Critical contraindication: Bupropion is absolutely contraindicated in binge-eating disorder and bulimia nervosa due to markedly elevated seizure risk. 1

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Cardiac Monitoring Requirements

• Monitor QTc intervals in patients with restrictive eating or severe purging, as they face risk of sudden cardiac death—up to one-third of deaths in anorexia nervosa are cardiac-related. 1, 6
• Serial electrocardiograms should be performed for patients with ongoing restrictive eating or severe purging to detect emerging cardiac risk. 1
• Most cardiac manifestations (bradycardia, QTc prolongation, cardiac muscle atrophy) are completely reversible with appropriate nutritional rehabilitation. 6

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Psychiatric Assessment and Coordination

Patients with suspected eating disorders should be referred to psychiatry for comprehensive psychiatric evaluation and coordination of a multidisciplinary treatment plan. 1

• Systematically screen for common comorbidities including depression (lifetime rates: 76.3% for bulimia nervosa, 65.5% for binge-eating disorder, 49.5% for anorexia nervosa), anxiety, obsessive-compulsive disorder, and suicidal ideation at every visit. 1, 7
• Suicide accounts for approximately 25% of deaths in anorexia nervosa, making psychiatric monitoring essential. 1, 2
• Assess for substance-use disorders, as these conditions influence medication selection and safety. 1

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Hospitalization Criteria

Patients with severe eating disorder complications must be medically stabilized in an acute care hospital setting before transfer to a specialized eating disorder program. 1

Indications for Immediate Hospitalization

• Severe bradycardia (heart rate <40–50 bpm), orthostatic dizziness, chest pain, syncope, or profound weakness. 2
• Significant orthostatic vital sign changes indicating cardiovascular instability. 1
• Acute food refusal, uncontrollable binge eating or purging, or emergence of suicidal thoughts. 2, 3
• Dangerous electrolyte abnormalities (hypokalemia, hyponatremia) or QTc prolongation. 1

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Common Pitfalls to Avoid

• Never prescribe appetite suppressants, weight-loss agents (phentermine, orlistat, GLP-1 agonists), or bupropion to patients with eating disorders due to risk of worsening restriction and serious adverse events. 1, 2
• Do not attempt rapid nutritional rehabilitation, as this increases the risk of fatal refeeding syndrome in severely malnourished patients. 1
• Do not delay hospitalization based on patient or family denial of illness severity—eating disorders are life-threatening conditions requiring aggressive early intervention. 1
• Do not rely on normal laboratory values to exclude serious illness; clinical assessment and vital signs are paramount. 1
• Medication monotherapy without concurrent psychotherapy is discouraged; psychotherapy remains the foundational treatment for all eating disorders. 1

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Ongoing Monitoring

• Measure weight and vital signs (including orthostatic measurements) at each visit to detect early signs of relapse. 1, 2
• Routine laboratory monitoring (complete blood count, comprehensive metabolic panel, electrolytes) helps identify medical complications before they become life-threatening. 2
• Reassess psychiatric comorbidities and suicidality at every clinical encounter. 1