Can Lisdexamphetamine (Vyvanse) cause tachycardia?

Lisdexamfetamine and Tachycardia

Yes, lisdexamfetamine (Vyvanse) can cause tachycardia as a common cardiovascular side effect due to its stimulant properties. The FDA drug label explicitly warns that CNS stimulants like lisdexamfetamine cause increases in heart rate (mean increase about 3 to 6 bpm) and recommends monitoring all patients for potential tachycardia 1.

Mechanism of Action and Cardiovascular Effects

Lisdexamfetamine is a prodrug of d-amphetamine used for ADHD treatment. It works through several mechanisms that can affect heart rate:

1. Sympathetic Nervous System Activation:

   • Increases sympathetic tone by activating the β-adrenergic receptor/cyclic adenosine monophosphate (cAMP)/PKA pathway 2
   • This directly increases heart rate, similar to other sympathomimetics

2. Specific Cardiovascular Effects:

   • Clinical studies show increases in pulse of 2.8-5.2 bpm depending on dose (30-70 mg/day) 3
   • A recent Cochrane review found amphetamines (including lisdexamfetamine) increase heart rate by an average of 3.71 beats per minute compared to placebo 4

Clinical Evidence

Research consistently demonstrates cardiovascular effects:

• In a 4-week clinical trial in adults with ADHD, changes in pulse from baseline were 2.8,4.2, and 5.2 bpm for lisdexamfetamine doses of 30,50, and 70 mg/day respectively (all statistically significant vs. placebo) 3
• Post hoc pulse outliers (pulse ≥100 bpm) occurred in 3.3% to 8.5% of subjects taking lisdexamfetamine 3
• A cardiopulmonary study found changes in heart rate recovery at 1 minute after exercise in adults taking lisdexamfetamine 5

Risk Factors and Monitoring

Certain patients are at higher risk for tachycardia with lisdexamfetamine:

• Patients with pre-existing cardiovascular conditions
• Those taking other medications that increase heart rate
• Patients with hyperthyroidism
• Individuals with anxiety disorders

Clinical Management

1. Pre-treatment Assessment:

   • Evaluate for structural cardiac abnormalities, cardiomyopathy, serious heart arrhythmias, or coronary artery disease before starting therapy 1
   • Obtain baseline vital signs including heart rate

2. Monitoring:

   • Regularly monitor heart rate and blood pressure during treatment 1
   • The American Heart Association recommends that patients with advanced cardiovascular disease, high blood pressure, or hyperthyroidism should not use these medications 6

3. Dose Considerations:

   • Start with lower doses (30mg) in patients with cardiovascular risk factors
   • Maximum daily dose is 70mg per day 6
   • Consider dose reduction if clinically significant tachycardia occurs

4. Patient Education:

   • Instruct patients to report palpitations, chest pain, or unexplained syncope
   • Advise that lisdexamfetamine can cause elevations in pulse rate and should be monitored 1

Special Considerations

• Drug Interactions: Concomitant use with MAOIs is contraindicated due to increased risk of hypertensive crisis 1
• Serotonin Syndrome: Caution when combining with serotonergic drugs (SSRIs, SNRIs, triptans) as this may worsen cardiovascular effects 1
• Long-term Effects: A population-based cohort study found little to no increased risk of major cardiovascular events in patients treated with lisdexamfetamine compared to other ADHD medications 7, but monitoring remains important

When to Discontinue or Seek Medical Attention

Patients should seek immediate medical attention if they experience:

• Heart rate consistently above 100 bpm at rest
• Palpitations with lightheadedness or chest pain
• Unexplained syncope
• Symptoms of serotonin syndrome (which can include tachycardia along with confusion, agitation, hyperthermia) 2

Tachycardia is a recognized and expected side effect of lisdexamfetamine that requires appropriate monitoring but rarely necessitates discontinuation unless severe or symptomatic.