Class
- Antiadrenergic, alpha-2 agonist
Clonidine
Commonly Prescribed for
(FDA approved in bold)
- Hypertension
- Gilles de la Tourette syndrome (GTS)
- Tics
- Attention deficit hyperactivity disorder (ADHD)
- Restless legs syndrome (RLS)
- Neuropathic pain
- Opioid detoxification
- Alcohol withdrawal
- Atrial fibrillation
- Growth delay
- Ulcerative colitis
- Hypertensive “urgency”
- Menopausal symptoms such as hot flashes
- Insomnia
- Hyperhidrosis
- Anesthesia
Clonidine
How the Drug Works
- Alpha-2 adrenergic agonist at 2A/B/C receptors Reduces sympathetic output from CNS, which decreases cardiac output, peripheral vascular resistance, and blood pressure. Specifically targets alpha-2 receptors in the brainstem vasomotor center, decreasing presynaptic calcium levels and the release of norepinephrine. May also reduce plasma renin activity and catecholamine excretion
- Its effect in GTS and ADHD may be due to actions at the level of the prefrontal cortex
Clonidine
How Long Until It Works
- Hypertension, withdrawal – less than 2 hours
- GTS – weeks to months
- RLS – days
Clonidine
If It Works
- In neurologic conditions such as tics, continue to assess effect of the medication and if it is still needed
Clonidine
If It Doesn’t Work
- GTS/Tics – Neuroleptics are often effective, but their use should be reserved for patients with significant social isolation or embarrassment
- RLS – Generally used as an adjunctive agent. Dopamine agonists are more effective
Clonidine
Best Augmenting Combos for Partial Response or Treatment-Resistance
- In hypertension, combine with treatments less likely to affect heart rate or cause orthostasis (angiotensin-converting enzyme inhibitors, diuretics)
- Tics and GTS symptoms may change over time. Many patients improve with age. Behavioral and psychological therapies are useful, and education and reassurance are all that is needed in mild cases
- Identify and treat comorbid conditions such as ADHD or obsessive compulsive disorder
Clonidine
Tests
- Monitor blood pressure and pulse at office visits
Adverse Effects (AEs)
Clonidine
How Drug Causes AEs
- Related to alpha-2 agonist effect – hypotension and sedation
Clonidine
Notable AEs
- Dry mouth, hypotension/syncope, weakness, fatigue, sedation, dizziness, impotence, vivid dreams/nightmares, rash or pruritus, nausea, and depression
Clonidine
Life-Threatening or Dangerous AEs
- Bradycardia, AV block, and prolongation of QTc interval may occur with higher doses. Rapid withdrawal can cause rebound hypertension
Clonidine
Weight Gain
- Unusual
Clonidine
Sedation
- Common