What is a potential risk associated with abruptly stopping clonidine?

Abruptly stopping clonidine can lead to rebound hypertension, which is a significant increase in blood pressure after the discontinuation of the medication. Clonidine works by stimulating alpha-2 adrenergic receptors in the brain, leading to decreased sympathetic outflow and lower blood pressure. When clonidine is suddenly withdrawn, there may be an overactivity of the sympathetic nervous system due to the absence of its inhibitory effects, resulting in a rapid rise in blood pressure. This may manifest in patients as a hypertensive crisis, characterized by severe hypertension and possibly associated symptoms. Therefore, it is crucial for patients on clonidine to taper the dose gradually under medical supervision to avoid this potential risk.