Clonidine (and Guanfacine)



Clonidine is an alpha 2 activating drug used to treat hypertensive urgency and ADHD. Stopping clonidine quickly may cause rebound hypertension.

Key Points

  • Clonidine, Guanfacine
    • Mechanism
      • Centrally-acting alpha-2 receptor agonists
        • Sympatholytic (inhibits fight-or-flight response)
        • ↓ central adrenergic outflow lowering neuronal norepinephrine release to the heart and systemic circulation
    • Indication
      • Hypertension
        • Including hypertensive urgency
      • ADHD
        • Second-line after stimulants (e.g. methylphenidate)
      • Tourette Syndrome
        • Specifically for intractable tics associated with TS
      • Symptom control in opioid withdrawal
    • Side Effects
      • Rebound hypertension with abrupt cessation
      • CNS depression
        • Bradycardia, hypotension, respiratory depression, miosis
      • Impotence
      • Does not decrease renal blood flow (MB)