Psychiatry· Topic 15.5 Addictive and eating disorders· 15.5.2

Bulimia nervosa

Bulimia nervosa is an eating disorder marked by recurrent binge eating with recurrent inappropriate compensatory behavior, such as self-induced vomiting, laxative misuse, fasting, or excessive exercise, occurring at least once weekly for 3 months in a patient whose weight is typically normal or above (body mass index above 18.5 kg/m2), which separates it from the binge-purge subtype of anorexia nervosa. The diagnosis is clinical; first-line treatment is cognitive behavioral therapy plus fluoxetine 60 mg PO once daily, avoiding bupropion because of an increased seizure risk.

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What this article covers

  • Overview

    Definition: bulimia nervosa is an eating disorder characterized by recurrent episodes of binge eating followed by recurrent inappropriate compensatory behavior to prevent weight gain, occurring at…

  • Epidemiology

    Sex and onset: prevalence is about three times greater in women than in men, and the median age of onset is 18 years.

  • Risk factors

    Female sex: the strongest demographic risk factor, with prevalence about three times that of men.

  • Pathophysiology

    The binge-purge cycle drives the physical findings: repeated large-volume eating followed by a compensatory behavior underlies essentially all of the downstream physical complications.

  • Clinical features

    Diagnostic criteria: recurrent episodes of binge eating (eating an objectively large amount of food within a discrete period, with a sense of loss of control) plus recurrent inappropriate…

  • Differential diagnosis

    Anorexia nervosa, binge-purge subtype: shares binge eating and purging, but BMI is below 18.5 kg/m2, whereas bulimia nervosa's weight is normal or above.

  • Diagnosis

    Diagnostic basis: the diagnosis is clinical, confirmed when a patient meets the criteria above (recurrent binge eating with recurrent compensatory behavior at least once weekly for 3 months…

  • Management

    First, address any medical emergency: hospitalize for intravenous fluid and electrolyte repletion if vital signs are unstable, the patient is significantly dehydrated, or the metabolic panel shows a significant electrolyte disturbance.

  • Complications

    Esophagogastric injury: repeated forceful retching produces a Mallory-Weiss tear, a partial-thickness mucosal laceration at the gastroesophageal junction; rarely, severe retching progresses to esophageal perforation (Boerhaave syndrome).

  • Prognosis

    Better than anorexia nervosa, but not benign: prognosis is more favorable than anorexia nervosa, though patients with bulimia nervosa still carry an elevated suicide risk.

  • Prevention

    Continue antidepressant therapy for relapse prevention: after remission, continue fluoxetine at the effective dose for continuation and maintenance, often 6 to 12 or more months, since untreated bulimia nervosa tends toward chronicity.

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