From the Guidelines
Guanfacine is a recommended non-stimulant medication for treating ADHD, particularly for patients who cannot tolerate or do not respond well to stimulant medications, as it has been shown to be efficacious in treating ADHD with a medium effect size compared to placebo 1.
Key Points
- Guanfacine is available in immediate-release (Tenex) and extended-release (Intuniv) formulations, with the extended-release version typically preferred for ADHD treatment.
- The usual starting dose is 1 mg once daily, which can be gradually increased to an optimal dose of 1-4 mg daily based on response and tolerability.
- Guanfacine works differently from stimulants by activating alpha-2A adrenergic receptors in the prefrontal cortex, which enhances working memory and reduces distractibility by strengthening prefrontal cortical network connections, as supported by studies such as 1.
- Unlike stimulants, guanfacine may take 2-3 weeks to show full therapeutic effects.
- Common side effects include sedation, fatigue, headache, and mild decreases in blood pressure and heart rate.
- Guanfacine can be used alone or in combination with stimulants for enhanced symptom control in some patients, and it is approved as an adjunctive therapy to stimulant medications in the USA 1.
Considerations
- Guanfacine has been shown to be associated with improved functional impairment and quality of life, and its effects on core ADHD symptomatology are well-documented 1.
- The medication should be taken consistently, and discontinuation should occur gradually to avoid rebound hypertension.
- Guanfacine may be considered as a first-line treatment option in certain cases, such as disruptive behavior disorders, tic disorder, Tourette's syndrome, and substance use disorders, where stimulants may be regarded as an unviable treatment option due to their dopaminergic activity 1.
- Clinicians should monitor patients for potential side effects, including somnolence, dry mouth, dizziness, irritability, headache, bradycardia, hypotension, and abdominal pain, as reported in studies such as 1 and 1.
From the FDA Drug Label
There have been spontaneous postmarketing reports of mania and aggressive behavioral changes in pediatric patients with attention-deficit hyperactivity disorder (ADHD) receiving guanfacine hydrochloride Safety and effectiveness in children under 12 years of age have not been demonstrated. Therefore, the use of guanfacine hydrochloride in this age group is not recommended.
The role of guanfacine in the treatment of Attention Deficit Hyperactivity Disorder (ADHD) is not well established, as safety and effectiveness in children under 12 years of age have not been demonstrated. However, there have been spontaneous postmarketing reports of guanfacine being used in pediatric patients with ADHD, with some reports of mania and aggressive behavioral changes.
- Key points:
- Not recommended for children under 12 years of age
- Spontaneous postmarketing reports of mania and aggressive behavioral changes in pediatric patients with ADHD
- Hallucinations have been reported in pediatric patients receiving guanfacine for treatment of ADHD 2
From the Research
Role of Guanfacine in ADHD Treatment
Guanfacine is a non-stimulant medication used in the treatment of Attention Deficit Hyperactivity Disorder (ADHD). The following points highlight its role:
- Guanfacine is effective in treating ADHD, with a significant improvement in symptoms compared to placebos 3.
- It is considered a second-line medication for ADHD, often used when stimulant medications are not effective or tolerated 3, 4.
- Guanfacine extended release (XR) is a formulation that is more effective for long-term management of ADHD and has fewer adverse effects compared to the immediate-release formulation 5.
Efficacy and Safety
The efficacy and safety of guanfacine in ADHD treatment are supported by several studies:
- A meta-analysis found that guanfacine was significantly more effective in treating ADHD, with a risk ratio of 1.78 compared to placebos 3.
- Guanfacine XR has been shown to be effective in reducing ADHD symptoms in children and adolescents, with a favorable safety profile 5, 4.
- Common adverse events associated with guanfacine include somnolence, fatigue, and headaches, but it is generally considered safe and well-tolerated 3, 5.
Clinical Utility
Guanfacine has clinical utility in the treatment of ADHD:
- It can be used as a monotherapy or as an adjunct to stimulant treatment 5, 6.
- Guanfacine XR is labeled for use in children and adolescents, and its efficacy and safety have been established in this population 5, 4.
- There is also evidence to support the use of guanfacine in adult patients with ADHD, with studies showing its efficacy and safety in this population 6.
Ongoing Research
Research is ongoing to further evaluate the efficacy and safety of guanfacine in ADHD treatment: