Home Drug Guide Clonidine

Drug Guide

Generic Name

Clonidine

Brand Names Catapres-tts-1, Catapres-tts-2, Catapres-tts-3, Nexiclon XR

Classification

Therapeutic: Antihypertensive, central alpha-2 adrenergic agonist

Pharmacological: Alpha-2 adrenergic agonist

FDA Approved Indications

Hypertension
ADHD (attention deficit hyperactivity disorder)
Scheduled opioid withdrawal

Mechanism of Action

Clonidine stimulates alpha-2 adrenergic receptors in the brainstem, reducing sympathetic outflow from the central nervous system, which decreases peripheral vascular resistance, heart rate, and blood pressure.

Dosage and Administration

Adult: For hypertension: typically 0.1 mg twice daily, titrated as needed. Transdermal patches: 0.1 to 0.3 mg/24 hours applied once weekly.

Pediatric: For ADHD: 0.1 mg orally twice daily, titrated as needed. Transdermal patches: 0.1 mg/24 hours applied once weekly.

Geriatric: Start at lower doses due to increased sensitivity; closely monitor response.

Renal Impairment: Use with caution; dosage adjustments may be necessary.

Hepatic Impairment: No specific adjustment; use cautiously.

Pharmacokinetics

Absorption: Well absorbed orally; transdermal absorption is steady over 24 hours.

Distribution: Widely distributed; crosses blood-brain barrier.

Metabolism: Partially hepatic metabolism.

Excretion: Renal excretion of unchanged drug and metabolites.

Half Life: 12-16 hours.

Contraindications

Known hypersensitivity to clonidine or components.
Use with caution in patients with a history of heart disease, cerebrovascular disease, or recent myocardial infarction.

Precautions

Monitor blood pressure closely during titration.
Potential for rebound hypertension if discontinued abruptly.
Use caution in pregnancy and breastfeeding; benefits and risks should be evaluated.

Adverse Reactions - Common

Dry mouth (Common)
Drowsiness (Common)
Dizziness (Common)
Fatigue (Common)

Adverse Reactions - Serious

Hypotension (Serious)
Rebound hypertension upon abrupt discontinuation (Serious)
Bradycardia (Serious)
Sedation or somnolence (Serious)

Drug-Drug Interactions

Beta blockers (additive bradycardia effect)
Other antihypertensives (potentiation)
CNS depressants (enhanced sedation)

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood pressure and heart rate regularly; assess for signs of orthostatic hypotension.

Diagnoses:

Risk for falls related to dizziness or hypotension.
Ineffective peripheral tissue perfusion due to hypotension.

Implementation: Ensure correct dosing especially during titration; educate patient on the importance of adherence; advise against abrupt discontinuation.

Evaluation: Regular monitoring of blood pressure to assess therapeutic effectiveness.

Patient/Family Teaching

Take medication exactly as prescribed; do not stop suddenly.
Notify healthcare provider if experiencing dizziness, fainting, or rapid heartbeat.
Avoid alcohol and CNS depressants unless approved.
Report any signs of allergic reactions or severe side effects.

Special Considerations

Black Box Warnings:

Rebound hypertension can occur if medication is suddenly discontinued; taper gradually.

Genetic Factors: No specific genetic considerations.

Lab Test Interference: May affect certain laboratory tests, including serum glucose levels.

Overdose Management

Signs/Symptoms: Hypotension, bradycardia, sedation, respiratory depression in severe cases.

Treatment: Supportive care, gastric lavage if ingestion is recent, activated charcoal, vasopressors for hypotension, atropine for bradycardia.

Storage and Handling

Storage: Store at room temperature away from moisture and heat.

Stability: Stable until expiration date on package.