What is the frequency of tachycardia as a side effect of Vyvanse (lisdexamfetamine)?

Frequency of Tachycardia with Vyvanse (Lisdexamfetamine)

Tachycardia occurs in approximately 2% of adults taking Vyvanse (lisdexamfetamine) for ADHD, with higher rates at increased doses, and pulse increases of 2.8-5.2 beats per minute are common depending on dosage. 1, 2

Cardiovascular Effects of Vyvanse

Vyvanse (lisdexamfetamine) is a prodrug stimulant medication that is converted to its active form d-amphetamine in the bloodstream. Like other stimulants, it can affect the cardiovascular system in the following ways:

Heart Rate Effects

• In clinical trials, Vyvanse caused dose-dependent increases in pulse:
  • 30 mg/day: +2.8 beats per minute
  • 50 mg/day: +4.2 beats per minute
  • 70 mg/day: +5.2 beats per minute 2

Incidence of Tachycardia

• Tachycardia was reported in 2% of adult ADHD patients taking Vyvanse compared to 0% on placebo 1
• Post hoc analysis showed pulse outliers (≥100 bpm) occurred in 3.3% to 8.5% of subjects taking Vyvanse 2
• Palpitations were reported in 2% of adult ADHD patients taking Vyvanse 1

Risk Factors for Tachycardia

The risk of developing tachycardia with Vyvanse appears to be influenced by:

1. Dose: Higher doses (50-70 mg) are associated with greater increases in heart rate 2
2. Treatment duration: Cardiovascular effects tend to diminish over time as tolerance develops 3
3. Pre-existing conditions: Patients with underlying cardiovascular conditions may be at higher risk

Clinical Monitoring Recommendations

When prescribing Vyvanse, cardiovascular monitoring should include:

• Baseline assessment: Evaluate heart rate and blood pressure before starting treatment
• Regular monitoring: Check vital signs at follow-up visits
• Dose adjustments: Consider lower doses in patients experiencing tachycardia
• Special attention: Monitor more closely in patients with:
  • History of cardiovascular disease
  • Hypertension
  • Family history of sudden cardiac death

Management of Tachycardia

If tachycardia occurs:

1. Evaluate severity: Determine if the tachycardia is symptomatic or asymptomatic
2. Consider dose reduction: Lower the dose if tachycardia is problematic
3. Timing adjustment: Administer medication earlier in the day to minimize sleep disruption
4. Treatment interruption: Consider drug holidays when appropriate
5. Alternative medication: Switch to a non-stimulant medication if tachycardia persists

Clinical Perspective

While tachycardia is a recognized side effect of Vyvanse, it's important to note that:

• Most cardiovascular effects are mild to moderate in severity 2
• Serious cardiovascular events are rare in patients without pre-existing cardiac conditions 3
• The FDA label for Vyvanse includes warnings about increased blood pressure and heart rate 1

Pitfalls to Avoid

• Overlooking pre-existing conditions: Always screen for underlying cardiovascular disease before prescribing
• Ignoring symptoms: Palpitations, chest pain, or shortness of breath warrant immediate evaluation
• Failure to monitor: Regular cardiovascular monitoring is essential, especially during dose adjustments
• Combining with other stimulants: Avoid concurrent use of caffeine or other stimulants that may exacerbate tachycardia

In conclusion, while tachycardia is a recognized side effect of Vyvanse occurring in approximately 2% of adult patients, most cases are mild to moderate and rarely lead to treatment discontinuation when properly monitored and managed.