Ethos Ho, BSc Pharm Student
What are Eating Disorders?
Eating disorders such as anorexia nervosa and bulimia nervosa, are currently listed as mental disorders in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5). Individuals who are affected by these illnesses are often stigmatised, with many viewing their illness as a lifestyle choice, making it more challenging for them to seek help. The stigma also increases their risk for lifelong complications, such as nutritional deficiencies, dehydration, osteoporosis, and hypoglycemia (low blood sugar levels).1,2 The misguided perceptions surrounding eating disorders stem not only from public opinion but also from healthcare professionals. In fact, clinicians who have limited experience treating eating disorders often express negative attitudes towards eating disorder patients.2 According to the DSM-5, eating disorders are characterized as disturbed eating-related behaviours that cause altered consumption of food and impaired health or functioning.1 The differences between anorexia nervosa and bulimia nervosa are described below.
Anorexia nervosa is characterised by a distorted body image and excessive dieting and primarily affects adolescent girls and young women. This disorder typically results in severe weight loss and a pathological fear of becoming overweight. According to the DSM-5, the diagnostic criteria for anorexia nervosa include:
- Restriction of energy intake relative to requirements, leading to low body weight
- Intense fear of becoming fat or persistent behaviour that interferes with weight gain
- Disturbance in the way body shape or weight is perceived
Bulimia nervosa is characterised by frequent episodes of binge-eating followed by inappropriate behaviours such as self-induced vomiting to avoid weight gain. This disorder typically presents in those who are within the “normal” to overweight range. In the DSM-5, the diagnostic criteria for bulimia nervosa include:
- Recurrent episodes of binge-eating
- Recurrent inappropriate compensatory behaviours to prevent weight gain (e.g. self-induced vomiting, misuse of laxatives or diuretics, fasting or excessive exercise)
- The binge-eating and compensatory behaviours occur at least once a week for ≥3 months
- Body shape and weight overly influence Self-perception
- The disturbance doesn’t occur exclusively during episodes of anorexia nervosa
How Do You Treat Eating Disorders?
The treatment of eating disorders is often complex and relies not only on the use of psychotropic drugs, but also nutritional counselling, psychotherapy, and the treatment of medical complications, if present.3 Today’s article focuses on pharmacological options that are used to treat eating disorders.
Goals of Treatment for Anorexia Nervosa3
Some major goals in the treatment of anorexia nervosa include:
- Weight gain and the prevention of weight loss after intensive care
- Change in eating behaviours and reduction of associated psychopathology (e.g. fear of becoming fat and preoccupation with body image)
- Treatment of associated psychiatric conditions such as depression, anxiety, and OCD
- Treatment of associated conditions, such as osteoporosis and infertility
Goals of Treatment for Bulimia Nervosa3
Some major goals in the treatment of bulimia nervosa include:
- Cessation of binge-eating behaviours
- Cessation of compensatory behaviours (e.g. self-induced vomiting, misuse of laxatives and diuretics)
- Reduction of associated psychopathology (e.g. fear of weight gain or becoming fat)
- Treatment of associated medical conditions
Pharmacological Treatments for Eating Disorders
Like other psychiatric disorders, the treatment of eating disorders often involves combining cognitive behavioural therapy with pharmacotherapy. However, there is still some debate about whether this strategy improves treatment efficacy in managing certain eating disorders and whether it improves treatment outcomes.2 Pharmacological options for treating eating disorders are described below.
Anorexia patients typically experience gastroparesis, a condition where there is poor emptying of food from the stomach into the intestine, creating a sensation of fullness. Prokinetic agents such as domperidone and metoclopramide (Metonia®) can help overcome this sensation of fullness and encourage food intake by increasing gastric emptying and intestinal motility. If domperidone or metoclopramide is ineffective, erythromycin may be added onto therapy.
The drug prucalopride (Resotran®) is a newer agent on the market that helps increase intestinal motility while also treating constipation, which is a frequent problem associated with weight loss.
Antipsychotics such as olanzapine (Zyprexa®) can be used to promote weight gain as well as to reduce any delusional thinking and obsessive thoughts surrounding food. Quetiapine (Seroquel®) is often used to manage anxiety for patients with eating disorders because it’s more effective and doesn’t carry the risk of dependence associated with benzodiazepines.
Antidepressants such as fluoxetine (Prozac®), trazodone and venlafaxine (Effexor® XR) are only used in patients with co-existing psychiatric conditions, such as depression, anxiety and obsessive-compulsive disorder (OCD).
In patients with anorexia nervosa, zinc gluconate can increase the rate of weight gain. Nausea is a common side-effect of oral zinc, but this can be reduced if it’s taken with food.
Benzodiazepines such as clonazepam (Rivotril®) can be used to treat severe anxiety associated with eating disorder recovery. However, unlike the antipsychotic quetiapine (Seroquel®), benzodiazepines carry the risk of dependence.
Cyproheptadine belongs to a class of medications called antihistamines, which are typically used to treat allergic conditions. However, this medication is associated with modest weight gain and may be used off-label to treat chronic anorexia nervosa. As well, its hypnotic properties may help with sleep.
The Bottom Line
Eating disorders such as anorexia nervosa and bulimia nervosa are mental disorders associated with disturbed eating-related behaviours and psychopathological thinking. The societal stigma surrounding eating disorders presents a challenge for patients who are seeking help and increases their risk for long-term complications such as osteoporosis and nutritional deficiencies. The treatment of eating disorders typically involves a combination of psychotherapy and pharmacological therapy; however, there is still some debate regarding the benefits and outcomes of this combination. Medication options for treating eating disorders include prokinetic agents, zinc gluconate, antidepressants, antipsychotics, benzodiazepines and cyproheptadine. The major uses for these medications are to address co-existing psychiatric conditions such as depression and anxiety, promote weight gain and reduce delusional thinking and behaviours.
As always, we hope you took away something valuable from this piece. If you have any questions or concerns regarding this article or others, feel free to reach out to us on Instagram, Facebook, or at email@example.com with your feedback. We’d love to hear from you.
- Bello, N., & Yeomans, B. (2017). Safety of pharmacotherapy options for bulimia nervosa and binge eating disorder. Expert Opinion On Drug Safety, 17(1), 17-23. doi: 10.1080/14740338.2018.1395854
- Aigner, M., Treasure, J., Kaye, W., & Kasper, S. (2011). World Federation of Societies of Biological Psychiatry (WFSBP) Guidelines for the Pharmacological Treatment of Eating Disorders. The World Journal Of Biological Psychiatry, 12(6), 400-443. doi: 10.3109/15622975.2011.602720