From the FDA Drug Label
DOSAGE AND ADMINISTRATION 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 The FDA drug label does not answer the question.
From the Research
The recommended dose of guanfacine for aggressive adults typically starts at 1 mg once daily, with gradual increases as needed up to 2-3 mg daily, divided into two doses. This dosing strategy is based on the most recent and highest quality study available, which suggests that low doses of guanfacine are more suitable for the treatment of patients with established but uncomplicated hypertension, due to the lack of peripheral α-mimetic effects in the lower dose range 1. Guanfacine, an alpha-2 adrenergic agonist, works by reducing sympathetic outflow from the brain, which helps modulate impulsivity and aggression by enhancing prefrontal cortical regulation of behavior.
Some key points to consider when prescribing guanfacine for aggressive adults include:
- Starting treatment at a lower dose to minimize side effects like sedation and hypotension
- Making dose adjustments every 3-7 days based on clinical response and tolerability
- Monitoring blood pressure and heart rate regularly, especially during dose adjustments
- Avoiding abrupt discontinuation, which can cause rebound hypertension
- Considering the use of guanfacine when first-line treatments have failed or are contraindicated, as its use for adult aggression is considered off-label
It's also important to note that guanfacine has been shown to be effective in reducing blood pressure in patients with hypertension, with daily dosages of 1,2, and 3 mg being comparable in efficacy 2, 3. Additionally, guanfacine has been compared to other centrally acting antihypertensive agents, such as clonidine and methyldopa, and has been found to have a similar efficacy in reducing blood pressure 4, 3. However, the most recent and highest quality study available suggests that guanfacine can be safely discontinued without significant increases in blood pressure or other tolerability parameters, compared to tapering the dose 1.