Side Effects of Vyvanse (Lisdexamfetamine)
Vyvanse causes common side effects that are generally mild to moderate and often transient, but requires monitoring for serious cardiovascular, psychiatric, and growth-related adverse events. 1
Most Common Side Effects
In Children and Adolescents (6-17 years) with ADHD
The most frequently reported adverse effects include 1:
- Decreased appetite/anorexia (most common)
- Insomnia and sleep disturbances
- Irritability
- Stomach/abdominal pain
- Weight loss
- Dizziness
- Nausea and vomiting
- Diarrhea
- Dry mouth
- Anxiety
In Adults with ADHD
Similar profile to pediatric patients 1:
- Loss of appetite
- Insomnia
- Dry mouth
- Anxiety
- Dizziness
- Weight loss
In Adults with Binge Eating Disorder
The side effect profile differs slightly 1:
- Dry mouth (36% vs 7% placebo) - most common
- Insomnia (20% vs 8% placebo)
- Decreased appetite (8% vs 2%)
- Increased heart rate (7% vs 1%)
- Feeling jittery (6% vs 1%)
- Constipation (6% vs 1%)
- Anxiety (5% vs 1%)
Serious Side Effects Requiring Monitoring
Cardiovascular Effects
Vyvanse causes statistically significant increases in blood pressure and heart rate that require regular monitoring. 2, 1 While effects are small at the group level, they can be clinically significant in patients with preexisting cardiovascular disease. Guidelines recommend monitoring pulse and blood pressure throughout treatment 2.
- Sudden death has occurred in patients with structural heart defects or serious heart disease 1
- Check for heart problems before starting treatment
- Monitor for chest pain, shortness of breath, or fainting
Growth Suppression in Children
Vyvanse causes dose-related reductions in height and weight gain that require careful monitoring. 2, 1
Specific data:
- After 4 weeks: weight loss of -0.9 to -2.5 pounds (30-70 mg doses) in children 6-12 years 1
- After 12 months of consistent treatment: mean percentile change of -13.4 in body weight 1
- Height effects: approximately 2 cm less growth over 3 years with continuous stimulant treatment 2, 1
- Effects are dose-related and similar for amphetamine and methylphenidate 2
Monitor height and weight regularly; consider treatment interruption if growth suppression is clinically significant.
Psychiatric Effects
New or worsening psychiatric symptoms can occur and require immediate evaluation. 1
- New or worsening bipolar disorder
- New psychotic symptoms (hallucinations, delusions)
- New manic symptoms
- Aggression and irritability
- Depression (though recent evidence suggests stimulants may actually decrease suicidality risk in ADHD patients) 2
Screen for personal and family history of psychiatric disorders before initiating treatment.
Peripheral Vasculopathy (Raynaud's Phenomenon)
Fingers or toes may become 1:
- Numb, cool, or painful
- Change color from pale to blue to red
- Develop unexplained wounds
Serotonin Syndrome
Risk increases when Vyvanse is combined with other serotonergic drugs (SSRIs, SNRIs, triptans, tramadol, fentanyl, lithium, St. John's Wort, MAOIs) 1.
Symptoms include: agitation, hallucinations, hyperthermia, tachycardia, seizures, confusion, muscle rigidity, changes in blood pressure, nausea, vomiting, diarrhea.
Sexual Side Effects
In adults with BED 1:
- Erectile dysfunction (2.6% males on Vyvanse vs 0% placebo)
- Decreased libido (1.4% vs 0%)
Abuse and Dependence Risk
Vyvanse has high potential for abuse, misuse, and addiction, though its prodrug formulation provides some protection against rapid-onset euphoria. 3, 1 The medication requires enzymatic conversion in red blood cells to become active, making it less amenable to intranasal or intravenous abuse compared to immediate-release amphetamines 3.
Monitor for signs of misuse, diversion, or substance use disorder, particularly in adolescents and adults with substance abuse history.
Postmarketing Adverse Events
Additional rare but serious effects reported include 1:
- Cardiomyopathy
- Seizures
- Rhabdomyolysis
- Stevens-Johnson Syndrome
- Eosinophilic hepatitis
- Anaphylactic reactions
- Intestinal ischemia
- Alopecia
Special Considerations
Gastrointestinal Retention
A case report documented retention of approximately 20 intact capsules in the gastrointestinal tract of an 11-year-old after 10 weeks of treatment, presenting with constipation and epigastric pain 4. This highlights the importance of monitoring for constipation, particularly in pediatric patients.
Pregnancy and Breastfeeding
- Advise patients to notify healthcare providers if pregnant or planning pregnancy 1
- Do not breastfeed while taking Vyvanse 1
- Limited data exists on pregnancy outcomes 5
Clinical Monitoring Algorithm
Before initiating treatment:
- Screen for cardiovascular disease, structural heart defects
- Assess personal/family psychiatric history
- Evaluate for substance abuse risk
- Obtain baseline blood pressure, heart rate, height, and weight
During treatment:
- Monitor blood pressure and heart rate at each visit
- Track height and weight regularly (especially in children)
- Assess for emergence of psychiatric symptoms
- Evaluate sleep and appetite
- Screen for signs of abuse or diversion
The side effect profile of Vyvanse is consistent with other amphetamine-based stimulants, with most adverse effects being mild to moderate, dose-related, and often transient 2, 6, 7. However, the serious cardiovascular, psychiatric, and growth-related effects necessitate systematic monitoring throughout treatment.