Home Drug Guide Chlorthalidone and Clonidine Hydrochloride

Drug Guide

Generic Name

Chlorthalidone and Clonidine Hydrochloride

Brand Names Combipres, Clorpres

Classification

Therapeutic: Antihypertensive, Diuretic

Pharmacological: Chlorthalidone - Thiazide-like diuretic; Clonidine - Alpha-2 adrenergic agonist

FDA Approved Indications

  • Hypertension

Mechanism of Action

Chlorthalidone inhibits sodium reabsorption in the distal tubules of the kidney, promoting diuresis. Clonidine stimulates alpha-2 adrenergic receptors in the brainstem, reducing sympathetic outflow, decreasing blood pressure.

Dosage and Administration

Adult: Dosage varies based on clinical response; typically, 12.5-25 mg daily for chlorthalidone and 0.1-0.3 mg twice daily for clonidine.

Pediatric: Use is not common; dosage should be individualized based on age and response.

Geriatric: Start at lower doses due to increased sensitivity and risk of side effects.

Renal Impairment: Adjust dose based on renal function; chlorthalidone can cause electrolyte imbalances.

Hepatic Impairment: Use with caution; monitor closely.

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Widely distributed in body tissues.

Metabolism: Clonidine undergoes hepatic metabolism; chlorthalidone undergoes minimal metabolism.

Excretion: Renal excretion of unchanged drugs and metabolites.

Half Life: Chlorthalidone: ~40-50 hours; Clonidine: ~12-16 hours.

Contraindications

  • Hypersensitivity to either drug
  • Severe coronary artery disease (clonidine caution)

Precautions

  • Orthostatic hypotension, renal impairment, hepatic impairment, pregnancy (clonidine caution), history of depression

Adverse Reactions - Common

  • Dry mouth (common)
  • Dizziness (common)
  • Fatigue (common)

Adverse Reactions - Serious

  • Bradycardia (rare)
  • Electrolyte disturbances (hypokalemia, hyponatremia) (common)
  • Rebound hypertension upon withdrawal (rare)

Drug-Drug Interactions

  • Other antihypertensives, CNS depressants, MAO inhibitors

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood pressure, heart rate, electrolyte levels, renal function.

Diagnoses:

  • Risk of hypotension
  • Electrolyte imbalance

Implementation: Administer as prescribed, monitor patient response, educate patient about orthostatic hypotension and adherence.

Evaluation: Assess blood pressure and side effects regularly.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Change positions slowly to minimize dizziness.
  • Do not discontinue abruptly to avoid rebound hypertension.
  • Report signs of electrolyte imbalance or severe side effects.

Special Considerations

Black Box Warnings:

  • Rebound hypertension if discontinued abruptly.
  • Clonidine withdrawal symptoms: hypertension, tremors, headaches, nervousness.

Genetic Factors: N/A

Lab Test Interference: N/A

Overdose Management

Signs/Symptoms: Severe hypotension, bradycardia, sedation, respiratory depression.

Treatment: Supportive care, airway management, fluid replacement, atropine for bradycardia, and specific antidotes if available.

Storage and Handling

Storage: Store at room temperature, away from moisture and light.

Stability: Stable under typical storage conditions.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.