From the Guidelines
Guanfacine should be initiated at a dose of 1 mg once daily, with titration by 1 mg/wk based on response and as tolerated to the recommended target dose range of 0.05 to 0.12 mg/kg/d or 1 to 7 mg/d. This recommendation is based on the most recent evidence from the American Journal of Obstetrics and Gynecology 1.
Key Considerations
- The dose titration should be gradual, allowing for assessment of response and tolerability.
- The recommended target dose range is 0.05 to 0.12 mg/kg/d or 1 to 7 mg/d, as specified in the study 1.
- It is essential to consider the limited information on the safety of guanfacine in pregnancy and the limited data on its efficacy for the treatment of ADHD in adults, as noted in the study 1.
Important Details
- Guanfacine could be considered in the treatment of ADHD following a risk-benefit discussion, acknowledging the very limited information on its safety in pregnancy and the limited data on its efficacy for the treatment of ADHD in adults.
- Alternative agents would be preferred due to the limited data available, as stated in the study 1.
- There are no published studies of guanfacine while breastfeeding, which should be taken into account when making treatment decisions 1.
From the FDA Drug Label
The recommended initial dose of guanfacine tablets, USP when given alone or in combination with another antihypertensive drug is 1 mg daily given at bedtime to minimize somnolence If after 3 to 4 weeks of therapy 1 mg does not give a satisfactory result, a dose of 2 mg may be given, although most of the effect of guanfacine hydrochloride is seen at 1 mg
- Initial dose: 1 mg daily
- Dose adjustment: may be increased to 2 mg after 3 to 4 weeks if 1 mg does not give a satisfactory result
- Maximum dose: higher daily doses have been used, but adverse reactions increase significantly with doses above 3 mg/day 2
From the Research
Guanfacine Dosage
- The recommended dosage of guanfacine for attention deficit hyperactivity disorder (ADHD) in children and adolescents is 1-4 mg once daily 3.
- In clinical trials, guanfacine extended-release (ER) was effective in reducing ADHD symptoms at dosages of 1-4 mg/day 3, 4.
- For adults with ADHD, the dosage of guanfacine extended-release (GXR) is typically titrated from 2 mg/d to 4-6 mg/d 5.
- A study in Japanese adults with ADHD found that GXR at dosages of 4-6 mg/d was effective in improving ADHD symptoms 5.
Dosage Optimization
- The dosage of guanfacine may need to be optimized for each individual patient to achieve the best response while minimizing adverse effects 3, 4.
- In clinical trials, the dosage of guanfacine was optimized over a period of several weeks to achieve the best response 3, 5.
Adverse Effects
- The most common adverse effects of guanfacine include somnolence, headaches, and fatigue 3, 6, 5.
- In clinical trials, the incidence of adverse effects was higher in patients receiving guanfacine compared to placebo 6, 5.
- However, most adverse effects were mild to moderate in severity and resolved over time 3, 5.