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Day # 147: Bulimia Nervosa Part 2

Today we will continue our current theme of eating disorders as we discuss bulimia nervosa. In part 1 we detailed an introduction, definitions, diagnostic criteria, epidemiology, and pathogenesis. Today, in part 2, we will cover clinical pearls, physical complications, and treatment.

Today's Content Level: Intermediate

Clinical Pearls 1, 2, 3, 4

•History: Bulimia nervosa (BN) is an eating disorder characterized by recurrent binge eating combined with behaviors intended to counteract the weight gain (purging). See part 1 for complete definitions and diagnostic criteria. The evaluation is similar to that described in a previous post on anorexia nervosa. Obtain a focused history regarding attitude toward themselves (self, body image, weight), food, and eating behaviors (meal pattern, eating, rituals, restrictions, frequency of weighing, binging, purging, etc.). Ask specifically about self-induced vomiting, misuse of medications (laxatives, diuretics, other medications), fasting, or excessive exercise. Binge eating commonly begins during or after an episode of dieting to lose weight and/or multiple stressful life events. Ask about any psychosocial stressors or triggers that exacerbate symptoms. Compared to anorexia nervosa, patients with bulimia experience their symptoms as more distressing (ego-dystonic), therefore they are often more likely to seek help. Patients are typically embarrassed by their binge eating and are highly focused on body weight and shape. A full psychiatric history should be obtained including a suicide/safety assessment. Patients may hide symptoms or present somatic complaints. Obtain collateral history if possible from family members, partners, or significant others.

•Optional Questionnaires: Eating Disorder Examination (EDE; clinician-administered), Eating Disorder Examination Questionnaire (EDE-Q; self-report), SCOFF Questionnaire, Bulimia Test-Revised (BULIT-R).

•Differential Diagnosis: The differential diagnosis includes medical conditions that lead to hyperphagia/binge eating (e.g. Kleine-Levin or Prader-Willi) or intractable nausea (e.g. gastric outlet obstruction or pregnancy). These medical disorders usually do not manifest as an intense fear of weight gain or disturbed body image. Other eating disorders should also be considered such as anorexia nervosa (AN) or binge eating disorder (BED). Both anorexia and bulimia are characterized by a desire for thinness and both may binge and purge, however individuals with bulimia maintain a normal weight (or are overweight). Diagnostic transition from initial bulimia to anorexia can occur (10-15% of cases) with multiple reversions/cross-overs between diagnostic criteria.

•Individuals with other mental disorders may display a disordered relationship with food or their body image but not meet full criteria for BN. Examples may include major depressive disorder (MDD) (atypical features = hyperphagia), borderline personality disorder (BPD) (binge-eating is included in the impulsive behavior criterion), OCD (obsessions/compulsions related to food), body dysmorphic disorder (preoccupied with imagined defects in their appearance), and schizophrenia (odd eating behaviors +/- weight loss).

•Comorbidities: High incidence of lifetime mood disorder (usually MDD), anxiety disorders, substance use (particularly alcohol or stimulants), and personality disorders (most frequently borderline PD).

Physical Findings and Medical Complications 5, 6, 7 , 8

Background

•BN is associated with a number of medical complications related to either weight gain/loss, binge-eating, and purging behaviors.

•High mortality rate (~2% per decade). This is lower than anorexia nervosa (~5-6% per decade). This is due to high rates of suicide, medical complications, or complications relating to substance use.

•A complete medical evaluation is necessary in order to assess for complications and determine whether hospitalization is necessary. This should include a full medical history, thorough review of symptoms, menstrual status, height, weight, vital signs, full physical exam, and laboratory testing.

Physical Exam, Medical Symptoms, and Labs

Some risks include:

High body mass index (BMI) (~33% of patients with BN have a BMI >30).
General -> Weakness, lethargy, and dehydration.
Cardiac -> Tachycardia (compare with bradycardia in anorexia), hypotension & orthostasis, peripheral edema, palpitations, arrhythmia (especially QTc prolongation), acute coronary syndrome, and conduction disorders.
GI -> Constipation, abdominal pain/distention, reflex/heartburn, esophagitis, and Mallory-Weiss tear.
Neuro -> Seizures.
Skin/Appearance -> Callouses/abrasions on the dorsum of the hand (Russell's sign from self-induced vomiting), dental erosion/caries, xerosis (dry, scaly skin), parotid gland swelling (sialadenosis), brittle hair and hair loss, or otherwise unexplained petechiae/subconjunctival hemorrhage/nose bleeds from self-induced vomiting.
Gyn -> Amenorrhea or oligomenorrhea.
Endo -> Type 2 Diabetes (2-3x greater than controls). Osteopenia and osteoporosis may be more common, particularly in patients who have had previous episodes of anorexia. Some evidence points towards increased risk of adrenal insufficiency (Addison's disease).
Other labs -> Hypochloremic hypokalemic alkalosis, metabolic acidosis (laxative abuse), elevated bicarbonate (compensation), hypernatremia, ↑ BUN (dehydration), and ↑ amylase.

Treatment 9, 10, 11, 12

•General approach: Mental health treatment should be focused on psychotherapy. Antidepressants have, however, shown clear benefit for bulimia nervosa (in contrast to anorexia). Many patients can be treated as an outpatient with an interdisciplinary approach (psychiatrist, primary care, dietician, therapist). Other treatment options include intensive outpatient, partial hospitalization programs, residential programs, and medical or psychiatric hospitalization depending on severity.

•Psychotherapy: Psychological interventions should be considered first-line treatment. Evidence supports the use of Cognitive Behavioral Therapy (CBT), Dialectical Behavior Therapy (DBT), Exposure and Response Prevention (ERP), Interpersonal Therapy (IPT), Family Therapy, Group Therapy, and focused Psychodynamic Therapy. Therapy aims to help restore healthy eating behaviors, reduce binge and purge frequency, change their relationship with food, improve body image, develop new sources of self-esteem, and help them better utilize their support systems.

•Pharmacotherapy: Fluoxetine is the only FDA approved medication for the treatment of bulimia nervosa (in adults) and should be considered as the first-line medication option. The effective dose is typically higher than average depression treatment (60-80 mg/day). Other SSRIs (e.g. sertraline, citalopram, escitalopram) have also demonstrated efficacy for reducing the frequency of binge eating and purging. Early response (at ~3 weeks) is a strong predictor of overall response. TCAs may be considered as second-line antidepressant treatment. Antidepressants may be considered for treatment of BN in adolescents, but they have little evidence and are not licensed for this practice. Other medications to consider that have reasonable evidence includes topiramate (↓ frequency of binge eating) and lisdexamfetamine (↓ frequency of binge eating; approved in binge-eating disorder). There is ongoing research on opioid antagonists given the relationships between feeding and the endogenous opioid system. Other medications that have been used with some benefit include SNRIs, lamotrigine, zonisamide, acamprosate, and sodium oxybate. Avoid bupropion due to its potential side effect to lower the seizure threshold.