Amber Rayfield, PharmD
PGY-2 Pharmacy Resident in Psychiatry
Eating disorders are serious mental health conditions which are associated with high mortality and morbidity making this an important topic for CPNP 2014. Presented by Lauren Flynn, MD, the session entitled Eating Disorders: What’s on the Menu for Pharmacologic Treatment, discussed the three common eating disorders of anorexia nervosa, bulimia nervosa, and binge eating disorder. Treatment targets were addressed including changing mindset, reducing frequency of behaviors, and restoring weight and physical well-being.
Criteria for this disorder per DSM-5 includes restriction of energy intake leading to a significantly low body weight, intense fear of gaining weight or resistance to gain weight, and body image distortion. The best therapy for these patients is food with goal of gradual weight gain of 2-3 pounds per week inpatient or 0.5-1 pound per week outpatient. Targeting a BMI of 20kg/m2 has shown best long term prognosis. Trials for medications have typically assessed the use of second generation antipsychotics, zinc, and antidepressants. Antipsychotic trials have shown an average increase in BMI of 0.5 as well as symptomatic improvement for depression and anxiety, with olanzapine showing most benefit. Zinc supplementation has also shown some efficacy in weight gain as low levels have correlated with degree of malnutrition. This mineral has shown symptomatic benefit in terms of depressive and anxiety symptoms as well. Conversely, trials comparing antidepressants with placebo have not found a significant difference in weight gain.
Criteria for this disorder per DSM-5 includes recurrent episodes of binge eating and inappropriate compensatory behaviors averaging at least once per week for three months. Fluoxetine is first line therapy as it is the only medication approved by the FDA for treatment of BN. The recommended dose is 60mg daily, which has been shown to reduce frequency of binge/purge episodes in the short-term. All other antidepressants including TCA, SSRI, and MAOI have shown comparable modest efficacy. Topiramate has shown efficacy in decreasing body weight and binge/purge episodes as well as increasing physical and social function.
Criteria for this disorder per DSM-5 includes recurrent episodes of binge eating occurring at least once per week for 3 months and marked distress about binge eating. The binge episodes are characterized with 3 or more of the following: rapid eating, eating beyond fullness, eating without hunger, eating associated with disgust, shame or excessive guilt. The main medications studied in BED treatment include antidepressants, antiepileptics, and anti-obesity agents. Out of all of these, topiramate and sertraline have been shown as the most efficacious. TCA, SSRI, and venlafaxine have shown some beneficial data in decreasing binge frequency and BMI. The anti-obesity drugs sibutramine (withdrawn from market due to cardiac concerns)and orlistat showed significant weight loss, but concerns exist for side effects.
Patients with eating disorders may experience a multitude of medical complications including gastrointestinal, metabolic abnormalities, elevated LFT, decreased kidney function due to dehydration, endocrine, and musculoskeletal. The first treatment goal is to restore weight and nutrition. Other secondary treatments may include calcium with vitamin D supplementation for osteoporosis; diuretic, beta blocker, and ACE-I for heart failure; electrolyte replacement for low levels; prokinetic agents, fiber, docusate, or polyethylene glycol for GI motility.
Psychiatric comorbidities are frequently seen in patients with eating disorders with depression and anxiety being the two most common. It is recommended to treat psychiatric comorbidities per guidelines with caution to malnutrition and medical comorbidities. Many medications may contribute to medical complications such as carbamazepine worsening osteopenia, bone marrow suppression, and hyponatremia; valproic acid worsening PCO; lithium worsening bone marrow suppression and renal insufficiency; topiramate worsening metabolic acidosis; bupropion, SSRI and quetiapine increasing seizure risk.
Another common comorbidity in patients with eating disorders is self-injurious behavior. Recommended treatment is naltrexone unless also taking opiates or if LFTs are elevated over three times upper limit.
Eating disorders have high morbidity and mortality. The best treatment includes an interdisciplinary team approach using medications, psychotherapy, and nutritional therapies. If medications are prescribed, medical comorbidities and malnutrition status should be kept in mind for safety.