Clonidine is a centrally acting alpha-2 adrenergic agonist used to treat hypertension, ADHD, opioid withdrawal, and certain pain or sleep disorders by reducing sympathetic outflow, which lowers heart rate and blood pressure while producing calming effects. Developed in the 1960s as a novel antihypertensive, it offered a safe and effective alternative to existing therapies and later found applications in neurology and addiction medicine. Clonidine is available orally, transdermally, or intravenously, is well absorbed, metabolized in the liver, and primarily excreted via the kidneys. Its development highlighted the therapeutic potential of central autonomic modulation, making it a versatile agent across cardiovascular, neurological, and psychiatric treatments.
