II. Indications
III. Mechanism
- See Alpha Adrenergic Central Agonist
- See Alpha Adrenergic Receptor
- Central Acting Adrenergic Agonists
- Activates alpha-2 receptors that inhibit CNS preganglionic sympathetic signals, lowering Blood Pressure
- Results in increased parasympathetic effects and side effects (e.g. sedation)
IV. Pharmacokinetics
- Renal excretion (unchanged in urine)
- Decrease dose in Renal Insufficiency, including starting dose
- Observe for adverse effects (Bradycardia, Hypotension)
- Oral Dosing
- Readily absorbed with 70% Bioavailability
- Activity
- Onset in 30-60 min
- Duration: 6-10 hours
V. Precautions
- See Clonidine Withdrawal
- Acute withdrawal risk with rebound Hypertension
- Do not stop suddenly (esp. if Clonidine dose >1.2 mg per day)
VI. Medications: Clonidine (Catapres) Tablet
-
Hypertension (adults)
- Start 0.1 mg orally twice daily
- Titrate dose weekly, modifying total daily dose 0.1 mg/day to typical dose of 0.2 to 0.6 mg/day divided twice daily
- Maximum total daily dose: 2.4 mg/day
-
Hypertensive Urgency (adults, other agents are preferred for Hypertensive Urgency )
- 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
-
Hypertension (children)
- Start 5 to 7 mcg/kg/day orally divided every 6 to 12 hours
- Titrate dose weekly, modifying total daily dose 5-25 mcg/kg/day in divided doses (maximal dose 0.9 mg/day)
-
Hot Flushes
- Start 0.1 mg orally at bedtime (or transdermal patch)
- May titrate up to 0.2 mg orally twice daily
VII. Medications: Clonidine Transdermal Patch (Catapress-TTS)
- Not recommended for use in children
- Available in 0.1, 0.2 and 0.3 mg/day patches (may combine patches up to two of the 0.3 mg/day patches)
- Start with a 0.1 mg/day patch
- Titrate to effective dose, up to maximum effective dose of 0.6 mg/day (two of the 0.3 mg/day patches)
- 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
- Day 1
VIII. Medications: Other forms
- Clonidine IV
- Epidural Clonidine (for Chronic Pain)
IX. Safety
- Pregnancy Category C
- Unknown Safety in Lactation
X. Adverse Effects
- See Clonidine Overdose
- See Alpha Adrenergic Central Agonist
- Somnolence
- Headache
- Dry Mouth
- Constipation
-
Bradycardia
- Risk of Sinus Node Dysfunction and Atrioventricular Block
- Increased risk when combined with Digoxin, Beta Blockers, nondihydropyridine Calcium Channel Blockers
- Hypotension
- Rebound Hypertension (if abruptly discontinued at higher dose)
- See Clonidine Withdrawal
- Risk increases with total daily doses >0.7 mg/day (esp. >1.2 mg/day)
- Slowly taper dose every 3 to 7 days to prevent rebound Hypertension
- Continue in Clonidine in the perioperative period
-
Sodium and water retention
- Reflex renin release in response to excessive Clonidine and renal hypoperfusion
XI. Drug Interactions
-
Tricyclic Antidepressants
- Decreased clonidine Antihypertensive effect
-
CNS Depressants (e.g. Alcohol, Benzodiazepines, Barbiturates)
- Increase Clonidine related CNS effects (e.g. Somnolence)
XII. Resources
- Clonidine (Stat Pearls)
- Clonidine Tablet (DailyMed)
- Clonidine Injection (DailyMed)
- Clonidine Patch (DailyMed)
XIII. References
- (2020) Med Lett Drugs Ther 62(1598): 73-80
- Mishler and Lovecchio (2017) Crit Dec Emerg Med 31(11): 15-20
- Olson (2020) Clinical Pharmacology, MedMaster, Miami, p. 64-5
Images: Related links to external sites (from Bing)
Related Studies
| clonidine (on 12/21/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
| CLONIDINE 0.1 MG/DAY PATCH | Generic | $7.33 each |
| CLONIDINE 0.2 MG/DAY PATCH | Generic | $12.01 each |
| CLONIDINE 0.3 MG/DAY PATCH | Generic | $16.08 each |
| CLONIDINE HCL 0.1 MG TABLET | Generic | $0.03 each |
| CLONIDINE HCL 0.2 MG TABLET | Generic | $0.04 each |
| CLONIDINE HCL 0.3 MG TABLET | Generic | $0.04 each |
| CLONIDINE HCL ER 0.1 MG TABLET | Generic | $0.34 each |
| catapres (on 2/23/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
| CATAPRES-TTS 1 PATCH | Generic | $7.33 each |
| CATAPRES-TTS 2 PATCH | Generic | $12.01 each |
| CATAPRES-TTS 3 PATCH | Generic | $16.08 each |
Ontology: Clonidine (C0009014)
| Definition (MSH) | An imidazoline sympatholytic agent that stimulates ALPHA-2 ADRENERGIC RECEPTORS and central IMIDAZOLINE RECEPTORS. It is commonly used in the management of HYPERTENSION. |
| Definition (CHV) | a hypertension treatment drug |
| Definition (NCI) | An imidazoline derivate and centrally-acting alpha-adrenergic agonist, with antihypertensive activity. Clonidine binds to and stimulates central alpha-2 adrenergic receptors, thereby reducing the amount of norepinephrine (NE) release and thus decreasing sympathetic outflow to the heart, kidneys, and peripheral vasculature. The reduction in sympathetic outflow leads to decreased peripheral vascular resistance, decreased blood pressure, and decreased heart rate. In addition, clonidine binds to imidazoline receptor subtype 1 (I1), which may also contribute to a reduction in blood pressure. |
| Definition (NCI_NCI-GLOSS) | The active ingredient in a drug used to treat high blood pressure. It is also being studied in the treatment of certain types of cancer pain. It blocks the release of chemicals from nerve endings that make blood vessels constrict (get narrower). Clonidine is a type of antihypertensive agent and a type of alpha-adrenergic agonist. |
| Definition (CSP) | alpha-2 adrenergic agonist that crosses the blood-brain barrier; acts centrally by reducing sympathetic tone, resulting in a fall in diastolic and systolic blood pressure and a reduction in heart rate; also acts peripherally. |
| Concepts | Pharmacologic Substance (T121) , Organic Chemical (T109) |
| MSH | D003000 |
| SnomedCT | 22139009, 372805007, 62782004 |
| LNC | LP32548-7, LP14987-9, MTHU002290 |
| English | Clofenil, Clonidine, Klofenil, 1H-Imidazol-2-amine, N-(2,6-dichlorophenyl)-4,5-dihydro-, N-(2,6-Dichlorophenyl)-4,5-dihydro-1H-imidazol-2-amine, clonidine, clonidine (medication), Clonidine [Chemical/Ingredient], CLONIDINE, cloNIDine, Clonidine (product), Clonidine (substance) |
| Swedish | Klonidin |
| Finnish | Klonidiini |
| Russian | KHLOFAZOLIN, GEMITON, KATAPRESAN, KLOFELIN, KLONIDIN, ГЕМИТОН, КАТАПРЕСАН, КЛОНИДИН, КЛОФЕЛИН, ХЛОФАЗОЛИН |
| Japanese | クロニジン塩酸塩, カタプレス, クロニジン, 塩酸クロニジン |
| Croatian | KLONIDIN |
| Polish | Klonidyna |
| Czech | clonidin, klonidin |
| Spanish | clonidina (producto), clonidina (sustancia), clonidina, Clonidina |
| French | Clonidine |
| German | Clonidin |
| Italian | Clonidina |
| Portuguese | Clonidina |
Ontology: Catapres (C0699881)
| Concepts | Pharmacologic Substance (T121) , Organic Chemical (T109) |
| MSH | D003000 |
| English | Catapresan, Catapressan, catapresan, catapres, Catapres |
