Clonidine (Catapres) Flashcards

Study Notes

Clonidine Overview

Clonidine, marketed as Catapres, is classified as an antihypertensive medication and falls under the adrenergics (centrally acting) pharmacological class.

Indications

Administered orally or transdermally for mild to moderate hypertension.
Used for attention-deficit hyperactivity disorder (ADHD) as either monotherapy or adjunctive treatment (specifically Kapvay).
Applied epidurally for managing cancer pain unresponsive to opioids.
Unlabeled uses include managing opioid withdrawal and adjunctive treatment for neuropathic pain.

Mechanism of Action

Acts by stimulating alpha-adrenergic receptors in the CNS, leading to decreased sympathetic outflow which inhibits cardioacceleration and vasoconstriction.
Prevents pain signal transmission by stimulating alpha-adrenergic receptors in the spinal cord.

Therapeutic Effects

Results in decreased blood pressure and pain relief.
Improves symptoms of ADHD.

Dosage Information

Oral dosage for adults and adolescents over 12 starts at 100 mcg twice daily, titrating to 200-600 mcg daily in divided doses, up to 2.4 mg/day.
For urgent hypertension treatment, an initial loading dose of 200 mcg is given, followed by hourly doses until control is achieved.
Transdermal patches deliver 100-300 mcg over 24 hours, applied weekly.
Epidural doses begin at 30 mcg/hr, titrated as needed.

Adverse Effects

Common side effects include drowsiness and dry mouth.
Other notable CNS effects include depression, dizziness, and hallucinations.
Cardiovascular effects may include AV block, bradycardia, and hypotension.
Gastrointestinal issues can involve dry mouth and constipation.
Risk of weight gain and paresthesia also noted.

Precautions

Caution advised in patients with serious cardiac or cerebrovascular conditions and those with renal insufficiency.

Contraindications

Hypersensitivity reactions contraindicate use.
Epidural administration is contraindicated with injection site infections or bleeding disorders.

Patient Assessments

Regular monitoring of intake/output, blood pressure, and pulse is essential during treatment.
Evaluate pain severity and symptoms of opioid withdrawal if applicable.
ADHD assessment should focus on attention span and impulse control.

Laboratory Tests

May temporarily elevate blood glucose levels.
Can cause decreased urinary catecholamines and vanillylmandelic acid (VMA) concentrations; abrupt withdrawal can reverse these changes.
May yield weakly positive Coombs' test results.

Drug Interactions

CNS depressants, such as alcohol and opioids, can cause additive sedation.
Antihypertensives and nitrates may enhance hypotensive effects.
Bradycardia risks are increased with beta blockers and calcium channel blockers.
MAO inhibitors, amphetamines, and tricyclic antidepressants can reduce clonidine's antihypertensive effect.
Withdrawal from beta blockers may exacerbate symptoms.

Patient Education

Patients should ensure an adequate supply of medication during weekends and holidays.
Encourage carrying a written prescription for emergencies.
Warn about potential drowsiness, particularly during initial treatment phases.

Description

Test your knowledge on Clonidine (Catapres) with these flashcards. This quiz covers therapeutic and pharmacological classifications, indications, and various uses of Clonidine. Perfect for students studying pharmacology or preparing for exams.