What medication is used for anorexia nervosa?

Medication Management for Anorexia Nervosa

There is no FDA-approved medication specifically for anorexia nervosa, and non-pharmacological therapy including cognitive behavioral therapy (CBT) and family-based treatment should be the mainstay of treatment. 1, 2, 3

First-Line Approach

Psychological Interventions

• Cognitive Behavioral Therapy (CBT) - Focus on challenging dysfunctional thoughts about food and addressing beliefs about "forbidden" foods
• Family-Based Treatment (FBT) - First-line for adolescents and young adults with involved caregivers
• Interpersonal Therapy (IPT) - May be effective as an alternative approach

Medication Considerations

When medications are considered as adjunctive therapy:

1. For comorbid depression/anxiety in anorexia:

   • Fluoxetine - May be considered but has limited evidence for weight gain in underweight patients
   • Mirtazapine (7.5-30 mg at bedtime) - May help with depression and potentially stimulate appetite 1

2. For severe cases with clinically significant bone loss:

   • Transdermal estradiol with cyclic progesterone - May be considered in young athletes (≥16 and <21 years) with BMD Z-scores ≤–2.0 and at least one additional risk factor 1
   • Caution with bisphosphonates - Should only be used in consultation with an endocrinologist due to teratogenicity concerns and limited evidence in this population 1

Special Considerations for Cancer-Related Anorexia

For cancer-related anorexia (not primary anorexia nervosa), consider:

• Megestrol acetate (400-800 mg/day)
• Olanzapine (5 mg/day)
• Dexamethasone (2-8 mg/day)
• Cannabinoids 1

Treatment Algorithm

1. Initial Assessment:

   • Evaluate BMI, medical stability, psychiatric comorbidities
   • Rule out medical causes of weight loss

2. Treatment Selection:

   • BMI <16 kg/m²: Consider higher level of care (inpatient/residential)
   • BMI 16-18.5 kg/m²: Intensive outpatient with multidisciplinary team

3. Medication Decision Points:

   • Primary focus should be on weight restoration through nutritional rehabilitation and psychotherapy
   • Consider medications only for specific comorbidities or complications
   • Monitor closely for adverse effects, particularly cardiac complications

Important Caveats

• Multiple studies have found limited utility in treating underweight anorexia patients with medications 4, 5, 3
• Neurobiological alterations during starvation may affect medication response 5
• Weight restoration is essential before medications can be effective for psychiatric symptoms
• Regular monitoring of vital signs, electrolytes, and cardiac function is necessary with any medication trial

Common Pitfalls to Avoid

• Focusing solely on medication without comprehensive psychological support
• Expecting medications to resolve core eating disorder pathology
• Premature return to sports/activities before adequate weight restoration
• Failing to involve a multidisciplinary team
• Inadequate monitoring for medical complications

The evidence for pharmacotherapy in anorexia nervosa remains limited, with no single medication showing consistent benefit for core symptoms. Treatment should prioritize nutritional rehabilitation, psychological interventions, and addressing medical complications, with medications serving primarily as adjunctive therapy for specific comorbidities.