What is a potential risk of abruptly discontinuing guanfacine treatment?

Discontinuing guanfacine, especially after prolonged use, can lead to rebound hypertension, which is a significant risk associated with the abrupt cessation of this medication. Guanfacine is an alpha-2 adrenergic agonist that helps to lower blood pressure. When it is stopped suddenly, the sympathetic nervous system can become overactive, resulting in an increase in blood pressure levels that can exceed the patient's baseline levels. This phenomenon occurs because the body has become accustomed to the effects of the medication, and without the drug's presence, there is an unopposed increase in norepinephrine activity, leading to heightened vascular resistance and an increase in heart rate.

This rebound effect can pose serious health risks, particularly in patients who have underlying cardiovascular issues, as it may lead to potential complications such as hypertensive emergencies. As such, it is generally recommended that guanfacine be tapered off slowly under medical supervision to prevent this potentially dangerous reaction.