Pharm
Clonidine
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Clonidine
, Catapres
See Also
Alpha Adrenergic Central Agonist
Clonidine Overdose
Clonidine Withdrawal
Guanabenz
(
Wytensin
)
Guanfacine
(
Tenex
)
Methyldopa
Indications
Hypertension
Vasomotor Symptoms of Menopause
Motor
Tic Management
(e.g.
Tourette's Syndrome
)
Opioid Withdrawal
Mechanism
See
Alpha Adrenergic Central Agonist
See
Alpha Adrenergic Receptor
Central Acting
Adrenergic Agonist
s
Activate alpha-2 receptors that inhibit CNS sympathetic signals
Results in increased parasympathetic effects and side effects
Pharmacokinetics
Renal excretion (unchanged in urine)
Decrease dose in
Renal Insufficiency
Precautions
See
Clonidine Withdrawal
Acute withdrawal risk with rebound
Hypertension
Do not stop suddenly (esp. if Clonidine dose >1.2 mg per day)
Preparations
Clonidine (Catapres) Tablet
Readily absorbed with 70% bioavailability
Start: 0.2 mg oral load
Titrate 0.1 mg/hour to:
Maximum of 0.7 mg
Diastolic
Blood Pressure
drops more than 20 mmHg
Activity
Onset in 30-60 min
Duration: 6-10 hours
Clonidine Transdermal
Patch
Available in 0.1, 0.2 and 0.3 mg/day dosing
Costs $40-100/month (depending on dose)
Changed every 7 days
Does not reach peak effect for 2-3 days
Once at level, delivers constant Clonidine rate over 7 days
Transition from oral to patch
Day 1
Apply transdermal Clonidine
Take full oral Clonidine dose
Day 2
Take 50% of oral Clonidine dose
Day 3
Take 25% of oral Clonidine dose
Discontinue oral Clonidine
Other forms
Clonidine IV
Epidural Clonidine (for
Chronic Pain
)
Adverse Effects
See
Clonidine Overdose
Somnolence
Headache
Dry Mouth
Constipation
Rebound
Hypertension
(if abruptly discontinued at higher dose)
See
Clonidine Withdrawal
Sodium
and water retention
Reflex renin release in response to excessive Clonidine and renal hypoperfusion
Drug Interactions
Tricyclic Antidepressant
s
Decreased Clonidine antihypertensive effect
CNS Depressant
s (e.g.
Alcohol
,
Benzodiazepine
s,
Barbiturate
s)
Increase Clonidine related CNS effects (e.g.
Somnolence
)
Resources
Clonidine (Stat Pearls)
https://www.ncbi.nlm.nih.gov/books/NBK459124/
References
Mishler and Lovecchio (2017) Crit Dec Emerg Med 31(11): 15-20
Olson (2020) Clinical Pharmacology, MedMaster, Miami, p. 64-5
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