For anorexia nervosa, the treatment drug of choice is food. In sufficient quantities over enough time, food will reverse virtually all of the laboratory and physical anomalies associated with the disorder. It will also reverse some psychiatric symptoms, such as mood instability, anxiety, impaired concentration and sleep disturbance.
Resist the temptation to use antidepressants for the mood disturbance because there is no evidence for their effectiveness in the underweight state.
For some patients, the anticipatory anxiety before an appropriate meal can be so overwhelming that short-acting benzodiazepines are used (e.g., lorazepam); however, there is no high-quality evidence beyond clinical experience to support benzodiazepines.
The seemingly delusional body image distortion in anorexia nervosa does not respond to antipsychotic medication. Do not use drugs that induce weight gain as a side-effect or drugs identified as appetite stimulants because the evidence shows they do not work. However, weight-recovered people with anorexia nervosa may require subsequent pharmacotherapy, given their long term vulnerability to mood and anxiety disorders.
A significant body of evidence exists for the efficacy of antidepressants in bulimia nervosa. Fluoxetine is the only such drug approved by Health Canada to treat bulimia nervosa, and the dose at which people typically respond is 60 mg per day in a single dose (20 mg per day, often effective in depression, was no different than placebo in a major clinical trial in bulimia nervosa). The published literature shows no evidence of increased suicidality with fluoxetine for this disorder. Common side-effects include sleep disturbance and decreased sexual desire and function.
For binge eating disorder, there is moderate evidence for the efficacy of various selective serotonin uptake inhibitors (SSRIs)—fluoxetine, fluvoxamine, sertraline, citalopram—with greater reductions in binge eating and other psychiatric symptoms compared with placebo. However, dropout rates and placebo response rates were high.
There is also more recent evidence for treating binge eating disorder with lisdexamfetamine (Vyvanse), a stimulant medication used to treat attention deficit/hyperactivity disorder. Treatment is initiated at 30 mg and titrated as needed and as tolerated up to 50 to 70 mg. The medication has been approved by Health Canada for this purpose.
In Eating Disorders: