Eating Disorders Are Notoriously Difficult to Treat

Pharmacy TimesSeptember 2022
Volume 88
Issue 09

Many drugs for these conditions enter clinical trials, but few demonstrate success.

Classified as serious psychiatric conditions, eating disorders not only have medical and psychological consequences but economic and societal repercussions as well.1-3

Notoriously difficult to manage, they usually require both behavioral and nutritional intervention.1,4 Nonresponse and relapse are common.5 And although clinicians use medications with varying degrees of success, few drugs are effective. Table 11,6-11 summarizes the 3 primary eating disorders: anorexia nervosa (AN), binge-eating disorder (BED), and bulimia nervosa (BN).

Pharmacologic Treatment

The following drug classes offer hopes for ameliorating or curing eating disorders.


Prescribed off label for BN, topiramate (median dosage 100 mg/day; range 25 to 400 mg/day) was superior to the placebo at reducing symptoms but also body weight.12 Although usually well tolerated at low doses, topiramate has been reported by some patients to cause cognitive haziness and paresthesia in fingers and toes.12 Results of zonisamide (Zonegran) trials indicated it can reduce binge eating and body weight in the short term and at 1-year follow-up but may be poorly tolerated.13-16


Unfortunately, randomized controlled trials (RCTs) have not identified any antidepressants that help manage AN.17,18 Neither first- nor second-generation antidepressants improve eating and weight outcomes. In addition, bupropion is contraindicated in eating disorders because of elevated seizure risk.17,18

Antidepressants are sometimes used successfully for BN. Experts prefer selective serotonin reuptake inhibitors (SSRIs) to first-generation antidepressants because of their better safety profile. Research supports the use of various SSRIs but suggests that high-dose fluoxetine is most effective. Two 8-week trials found that participants taking 60 mg per day of fluoxetine experienced significantly less binge eating and vomiting than those taking 20 mg per day and those taking placebo.19,20 Other trials have found that participants who continued on fluoxetine were significantly less likely to relapse and that the drug is also effective in adolescents.21-23 Fluoxetine was approved by the FDA in 1994 for maintenance of BN.24

The use of citalopram, escitalopram, fluvoxamine, and fluoxetine for BED is similar to the use of fluoxetine for BN.13 In general, SSRIs reduce binge eating when compared with placebo. A recent meta-analysis of 7 placebo-controlled RCTs found that treatment with antidepressants also reduces remission rates.25 However, antidepressants have no effect on the weight of individuals with BED.


Research results showed that olanzapine, an atypical antipsychotic, has a modest effect on weight restoration.26-28 In a recent RCT, 152 adult outpatients with AN received olanzapine (median dosage 7.77 mg/day; range 2.5 to 10 mg/day) or placebo for 16 weeks. Olanzapine was associated with an average gain of approximately 1 lb per month more than placebo. However, the cognitive rigidity and obsessionality associated with AN—and the self- reported anxiety—did not improve significantly.29


Investigators have also turned to stimulants for BED because of their tendency to suppress appetite. The FDA approved lisdexamfetamine for use in BED in 2015. A short, double-blind RCT compared the chemical (30 mg/ day, 50 mg/day, and 70 mg/day) with placebo. Binge eating decreased significantly more in participants taking 50- and 70-mg doses than in those taking placebo.30 Two additional 12-week studies replicated these results and found that body weight, general well-being, and obsessive-compulsive symptoms had also improved.30 Subsequent studies suggest lisdexamfetamine may prevent relapse better than placebo.31 Although considered effective and safe, lisdexamfetamine has adverse effects and a potential for abuse that should prompt careful pretreatment evaluation and monitoring during treatment.24 Limited research is available to support the use of other stimulants in BED. Table 212-30 summarizes the use of medication in eating disorders.


Although many drugs have been studied as a treatment for eating disorders, few have demonstrated success. AN continues to be the most difficult to manage. Better outcomes have been obtained in BN and BED, and as a result the FDA has approved 2 agents: fluoxetine 60 mg per day for BN and lisdexamfetamine for BED.

About The Author

Jeannette Y. Wick, MBA, RPh, FASCP, is the director of pharmacy professional development at the University of Connecticut in Storrs.


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19. Fluoxetine Bulimia Nervosa Collaborative Study Group.Fluoxetine in the treatment of bulimia nervosa. A multicenter, placebo-controlled, double-blind trial. Arch Gen Psychiatry. 1992;49(2):139-147.

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21. Romano SJ, Halmi KA, Sarkar NP, Koke SC, Lee JS. A placebo-controlled study of fluoxetine in continued treatment of bulimia nervosa after successful acute fluoxetine treatment. Am J Psychiatry. 2002;159(1):96-102. doi:10.1176/appi.ajp.159.1.96

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23. Kotler LA, Devlin MJ, Davies M, Walsh BT. An open trial of fluoxetine for adolescents with bulimia nervosa. J Child Adolesc Psychopharmacol. 2003;13(3):329-335. doi:10.1089/104454603322572660

24. Bello NT, Yeomans BL. Safety of pharmacotherapy options for bulimia nervosa and binge eating disorder. Expert Opin Drug Saf. 2018;17(1):17-23. doi:10.1080/14740338.2018.1395854

25. Stefano SC, Bacaltchuk J, Blay SL, Appolinário JC. Antidepressants in short-term treatment of binge eating disorder: systematic review and meta-analysis. Eat Behav. 2008;9(2):129-136. doi:10.1016/j.eatbeh.2007.03.006

26. Bissada H, Tasca GA, Barber AM, Bradwejn J. Olanzapine in the treatment of low body weight and obsessive thinking in women with anorexia nervosa: a randomized, double-blind, placebo-controlled trial. Am J Psychiatry. 2008;165(10):1281-1288. doi:10.1176/appi.ajp.2008.07121900

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29. Attia E, Steinglass JE, Walsh BT, Wang Y, Wu P, Schreyer C, et al. Olanzapine versus placebo in adult outpatients with anorexia nervosa: a randomized clinical trial. Am J Psychiatry. 2019;176(6):449-456. doi:10.1176/appi.ajp.2018.18101125

30. McElroy SL, Mitchell JE, Wilfley D, Gasior M, Ferreira-Cornwell MC, McKay M, et al. Lisdexamfetamine dimesylate effects on binge eating behaviour and obsessive-compulsive and impulsive features in adults with binge eating disorder. Eur Eat Disord Rev. 2016;24(3):223-231. doi:10.1002/erv.2418

31. Hudson JI, McElroy SL, Ferreira-Cornwell MC, Radewonuk J, Gasior M. Efficacy of lisdexamfetamine in adults with moderate to severe binge-eating disorder: a randomized clinical trial. JAMA Psychiat. 2017;74(9):903-910. doi:10.1001/jamapsychiatry.2017.1889

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