Bulimia Nervosa

Bulimia nervosa is an eating disorder in which people suffer recurrent episodes of uncontrolled overeating (binges).¹ The three key features are:²

• Intense preoccupation with body weight and shape.
• Repetitive episodes of binge eating (uncontrollably eating a large quantity of food, usually within less than two hours).
• Binge eating reinforces people's fear of becoming fat and leads to a cycle of repeated counteractive extreme weight control behaviour, such as:
  • Self induced vomiting
  • Laxative and diuretic abuse
  • Fasting
  • Excessive exercise

• Bulimia nervosa occurs in about 1% to 2% of Western women aged 16 to 35 years.
• It occurs across all socioeconomic groups.
• About one in 10 sufferers is male.²
• It is estimated that only 10% of cases seek medical help.

Risk factors

• Parental and childhood obesity.
• Family dieting.
• Critical comments about weight, or body shape, or both.³
• Having parents with an eating disorder.
• A history of sexual or physical abuse.
• Parental and pre-morbid psychiatric disorder.
• Parental problems, such as high expectations, low care and overprotection, and disruptive events in childhood such as parental death and alcoholism.

• The history usually dates back to adolescence. It is important to understand the context in which the disorder developed, and to identify risk factors. The core features include:
  • Regular binge eating. Loss of control of eating during binges.
  • Attempts to counteract the binges: e.g. vomiting, using laxatives, diuretics, dietary restriction and excessive exercise.
  • Preoccupation with weight, body shape, and body image.
  • Preoccupation with food and diet. This is often rigid or ritualistic, and deviations from a planned eating programme cause distress. Therefore starts to avoid eating with others and becomes isolated.
  • Severe comorbid conditions, e.g. depression and substance abuse, are common in patients with bulimia nervosa.²
• Physical examination is usually normal and is mainly aimed at excluding medical complications such as dehydration or dysrhythmias (induced by hypokalaemia).
• Examination must include height and weight (and calculation of the BMI) and blood pressure.
• Russell's sign (calluses form on the back of the hand, caused by repeated abrasion against teeth during inducement of vomiting).

• Binge eating disorder: more common in men and affects wider age range.⁴
• Sporadic bingeing in other psychiatric disorders, e.g. depression.
• Anorexia nervosa with bulimic features.
• Other forms of eating disorder which can be difficult to classify.⁵
• Medical causes of bingeing or vomiting.

• Are usually normal apart from serum potassium, which is often low.
• Renal function and electrolytes should be checked in view of frequent self-induced vomiting.

• People with bulimia nervosa should be referred to secondary care for assessment and management. However primary care has a significant role to play in patient management and support.
• The great majority of patients with bulimia nervosa can be treated as outpatients. There is a very limited role for the inpatient treatment of bulimia nervosa. This is primarily concerned with the management of suicide risk or severe self-harm, or for low serum potassium.
• As a first step, patients should be encouraged to follow an evidence-based self-help programme, with direct encouragement and support from health care professionals.⁶
• Cognitive behaviour therapy for bulimia nervosa (CBT-BN), a specifically adapted form of CBT, should be offered to adults with bulimia nervosa.^1,7 The course of treatment should be for 16 to 20 sessions over 4 to 5 months. When people with bulimia nervosa have not responded to or do not want CBT, other psychological treatments, e.g. interpersonal psychotherapy, should be considered.
• Pharmacological interventions for bulimia nervosa: as an alternative or additional first step to using an evidence-based self-help programme, adults with bulimia nervosa may be offered a trial of an antidepressant drug,¹ which can reduce the frequency of binge eating and purging, but the long-term effects are unknown. SSRIs, specifically fluoxetine, are the drugs of first choice. The effective dose of fluoxetine is 60 mg daily with a maximum dose of 80 mg once daily (not recommended in children and adolescents under 18 years).
• Management of physical aspects:
  • Patients with bulimia nervosa who are vomiting frequently or taking large quantities of laxatives (especially if they are also underweight) should have their fluid and electrolyte balance assessed frequently. if electrolyte disturbance is detected, it is usually sufficient to focus on eliminating the behaviour responsible.
  • Recommend regular dental reviews and dental hygeine (e.g. rinse mouth after vomiting).
  • Reduce laxatives slowly.
  • Screen for osteoporosis.

• Haematemesis, and metabolic complications (e.g. hypokalaemia) following excessive self-induced vomiting.
• Dental erosions.
• There may be painless enlargement of the salivary glands, tetany and seizures.

• About 50% of patients make a complete recovery, but the long-term outcome is unknown.⁸