What stimulant, such as lisdexamfetamine (Vyvanse), can help manage symptoms of binge eating disorder in a patient with a history of eating disorders?

Lisdexamfetamine for Binge Eating Disorder

Lisdexamfetamine (Vyvanse) 50-70 mg/day is the only FDA-approved stimulant for treating moderate to severe binge eating disorder in adults and should be prescribed when psychotherapy shows minimal response by 6 weeks. 1, 2

FDA-Approved Indication and Dosing

• Lisdexamfetamine is specifically approved for moderate to severe binge eating disorder (BED) in adults, making it the only pharmacological agent with regulatory approval for this eating disorder. 2, 3
• The recommended dose range is 50-70 mg/day, with dose titration typically starting lower and increasing as tolerated. 3, 4
• Lisdexamfetamine is NOT indicated for weight loss, and its use for obesity has not been established as safe or effective—this is a critical distinction from its BED indication. 2

Treatment Algorithm for Binge Eating Disorder

First-line approach:

• Initiate eating disorder-focused cognitive-behavioral therapy (CBT) or interpersonal therapy as the primary treatment modality. 1, 5

When to add pharmacotherapy:

• If psychotherapy shows minimal response by 6 weeks, add either lisdexamfetamine or an antidepressant (particularly SSRIs) to the treatment regimen. 1
• Lisdexamfetamine can also be prescribed initially for patients who prefer medication or as combination therapy from the start. 1, 5

Evidence for Efficacy

• Two pivotal Phase III trials demonstrated that lisdexamfetamine 50-70 mg/day produced significantly greater reductions in binge eating days per week compared to placebo, with effect sizes ranging from 0.83 to 0.97. 3, 4
• The number needed to treat (NNT) for clinical response was 3, and NNT for remission (defined as 4-week cessation of binge eating) was 4—these are highly robust treatment effects. 4
• Long-term studies up to 52 weeks showed that lisdexamfetamine markedly reduced the risk of BED relapse compared to placebo. 3
• Weight reduction of 5.2-6.25% occurred with lisdexamfetamine 50-70 mg/day, though weight loss is not the primary treatment goal. 4

Mechanism of Action

• Lisdexamfetamine is a prodrug of dextroamphetamine that reduces binge eating through combined effects on appetite/satiety, reward pathways, and cognitive processes including attention and impulsivity/inhibition. 6
• These effects are mediated by catecholamine (dopamine and norepinephrine) and serotonin mechanisms in the brain. 6, 7

Critical Contraindications and Safety Concerns

Absolute contraindications:

• History of anorexia nervosa or bulimia nervosa—naltrexone/bupropion specifically lists these as contraindications due to seizure risk, and stimulants carry similar concerns. 8
• Current or recent (within 14 days) use of monoamine oxidase inhibitors (MAOIs). 2
• Known hypersensitivity to amphetamine products. 2
• Advanced arteriosclerosis, symptomatic cardiovascular disease, moderate to severe hypertension, or hyperthyroidism. 2

Relative contraindications requiring careful assessment:

• History of drug abuse or dependence—lisdexamfetamine is a Schedule II controlled substance with abuse potential. 8, 2
• Uncontrolled hypertension, active coronary disease, glaucoma, anxiety, or insomnia. 8
• Psychotic disorders or bipolar disorder with active mania—stimulants can precipitate or worsen psychosis. 8

Monitoring Requirements

Before initiating treatment:

• Assess cardiovascular risk factors and consider electrocardiogram if cardiac disease is suspected. 2
• Screen for history of substance abuse, psychiatric conditions (especially psychosis and bipolar disorder), and current medications. 8, 2
• Document baseline binge eating frequency, weight, BMI, blood pressure, and heart rate. 1, 5

During treatment:

• Monitor blood pressure and heart rate regularly, as lisdexamfetamine increases both. 2
• Track binge eating frequency as the primary outcome measure, not weight loss. 1, 4
• Assess for emergence of psychiatric symptoms including psychosis, mania, depression, or suicidality. 2
• Monitor for signs of abuse, misuse, or diversion of medication. 2

Common Adverse Effects

• The most frequent adverse events (incidence ≥10% and greater than placebo) include dry mouth (NNH=4), decreased appetite (NNH=11), insomnia (NNH=11), and headache (NNH=19). 4
• Most adverse events are mild to moderate in intensity and rarely lead to discontinuation—the NNH for discontinuation due to adverse events was 44. 4
• The tolerability profile in BED patients is similar to that observed in ADHD populations. 3

Critical Pitfalls to Avoid

• Do not prescribe lisdexamfetamine for patients with current or past anorexia nervosa or bulimia nervosa—these are contraindications for related medications and stimulants pose similar risks. 8
• Do not use lisdexamfetamine as a weight loss medication—this is explicitly not an approved indication and other sympathomimetics used for weight loss have been associated with serious cardiovascular adverse events. 2
• Do not prescribe to patients with active substance use disorders or recent stimulant abuse—lisdexamfetamine has high abuse potential as a Schedule II controlled substance. 8, 2
• Do not combine with MAOIs or prescribe within 14 days of MAOI discontinuation—this combination can cause severe hypertension and cerebrovascular accidents. 8, 2
• Do not ignore cardiovascular screening—sudden death has occurred in patients with structural cardiac abnormalities or serious heart disease taking stimulants. 2

Special Populations

Bipolar disorder:

• For bipolar patients with binge eating disorder, ensure mood stabilization is achieved before adding lisdexamfetamine, as stimulants can precipitate manic episodes. 1
• Maintain mood stabilization with medications that do not cause weight gain while treating the BED. 1

Pregnancy and breastfeeding:

• Lisdexamfetamine may harm the unborn baby and passes into breast milk—breastfeeding is not recommended during treatment. 2