From the Guidelines
Adding guanfacine 1 mg to Vyvanse 40 mg may be beneficial if Vyvanse alone isn't providing adequate symptom control, but this decision should only be made by a healthcare provider. Guanfacine is an alpha-2 adrenergic agonist that can complement stimulants like Vyvanse by improving impulse control, reducing hyperactivity, and managing side effects such as irritability or sleep problems. The combination therapy works through different mechanisms - Vyvanse primarily increases dopamine and norepinephrine, while guanfacine modulates norepinephrine activity in the prefrontal cortex.
Key Considerations
- Starting with a low dose of guanfacine (1 mg) is appropriate, typically taken once daily, often in the evening due to potential sedation 1.
- This combination may cause side effects including drowsiness, fatigue, dry mouth, or blood pressure changes, so regular monitoring by your doctor is essential 1.
- The full benefits of adding guanfacine may take 2-4 weeks to develop, so patience is needed when evaluating its effectiveness 1.
Mechanism and Efficacy
- Guanfacine has been shown to be efficacious in treating ADHD, with a medium effect size compared to placebo 1.
- The combination of guanfacine and stimulants, such as Vyvanse, may increase treatment effects and/or decrease adverse effects of stimulants, predominantly sleep disturbances and cardiovascular effects 1.
Safety and Monitoring
- Guanfacine may be associated with changes in cardiovascular parameters, such as decreased heart rate and blood pressure, so monitoring is necessary 1.
- Regular assessment of medication adherence and potential issues in adherence is crucial to ensure the effectiveness of the treatment regimen 1.
From the Research
Efficacy of Guanfacine and Vyvanse
- The efficacy of guanfacine extended release (GXR) and lisdexamfetamine dimesylate (LDX), the active ingredient in Vyvanse, has been evaluated in several studies 2, 3, 4, 5, 6.
- Guanfacine extended release has been shown to be effective in treating attention-deficit/hyperactivity disorder (ADHD) with a moderate efficacy and good tolerability profile 2.
- Lisdexamfetamine dimesylate has been demonstrated to be a useful treatment option for patients with ADHD, with a strong efficacy and safety profile 3, 4.
Combination Therapy
- There is limited information available on the efficacy and safety of combining guanfacine with Vyvanse.
- However, a study comparing the efficacy of GXR and atomoxetine (ATX) using matching-adjusted indirect comparison methodology found that GXR appears to be more efficacious than ATX for the treatment of ADHD 6.
- Another study evaluating the efficacy and safety of multiple treatments for ADHD found that LDX has the highest efficacy and a relatively lower rate of adverse effects compared to other treatments, including GXR 5.
Dosage and Administration
- The recommended dosage of guanfacine extended release is 0.09-0.12 mg/kg/day, while the recommended dosage of Vyvanse is 30-70 mg/day 6.
- The study evaluating the combination of GXR and ATX used a target dose of 0.09-0.12 mg/kg/day for GXR and 1.2 mg/kg/day for ATX 6.
- It is unclear whether adding 1 mg of guanfacine to 40 mg of Vyvanse would be effective and safe, as there is limited information available on this specific combination.