Clonidine & Guanfacine
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Sympathomimetics and Sympatholytics (New)
- Isoproterenol
- Dobutamine
- Norepinephrine
- Alpha-Methyldopa
- Midodrine
- Clonidine & Guanfacine
- Phenylephrine
- Epinephrine
- Dopamine
Summary
Clonidine and guanfacine are sympatholytic drugs that suppress the body’s fight or flight response. They work by activating alpha-2 receptors.
Clinically, these drugs are used to treat Tourette syndrome, ADHD, and opioid withdrawal. They may also be used to treat hypertensive emergencies in limited situations.
Side effects of clonidine and guanfacine include hypotension, miosis, CNS depression, bradycardia, and respiratory depression. Notably, these drugs can cause rebound hypertension when stopped abruptly.
Key Points
- Clonidine, Guanfacine
- Drug Class
- Sympatholytic (inhibits fight-or-flight response)
- ↓ central adrenergic outflow lowering neuronal norepinephrine release to the heart and systemic circulation
- Sympatholytic (inhibits fight-or-flight response)
- Mechanism
- Alpha-2 receptor agonists
- Centrally-acting
- Alpha-2 receptor agonists
- Clinical Use
- Treats Hypertensive Urgency (limited situations)
- Treats ADHD
- Second-line after stimulants (e.g. methylphenidate)
- Treats Tourette Syndrome
- Specifically for intractable tics associated with TS
- Symptom control in opioid withdrawal
- Side Effects
- Rebound hypertension with abrupt cessation
- CNS depression (sedation)
- Bradycardia
- Hypotension
- Respiratory depression
- Miosis
- Drug Class