Home Drug Guide Guanabenz Acetate

Drug Guide

Generic Name

Guanabenz Acetate

Brand Names Wytensin

Classification

Therapeutic: Antihypertensive

Pharmacological: Alpha-2 adrenergic agonist

FDA Approved Indications

  • Hypertension

Mechanism of Action

Guanabenz binds to alpha-2 adrenergic receptors in the central nervous system, reducing sympathetic outflow, thereby decreasing peripheral vascular resistance and lowering blood pressure.

Dosage and Administration

Adult: Initially, 32 mg per day in divided doses; may be titrated up to 64 mg per day based on response.

Pediatric: Not typically used in children.

Geriatric: Start at lower doses due to potential increased sensitivity; titrate carefully.

Renal Impairment: Use with caution; dose adjustments may be necessary based on severity.

Hepatic Impairment: Use with caution; monitor liver function as needed.

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Widely distributed; crosses the blood-brain barrier.

Metabolism: Primarily metabolized in the liver.

Excretion: Excreted mainly in the urine.

Half Life: Approximately 8 hours.

Contraindications

  • Known hypersensitivity to Guanabenz or similar agents.

Precautions

  • Use with caution in patients with impaired hepatic or renal function.
  • Careful monitoring of blood pressure is necessary to avoid hypotension.
  • Potential for sedation and dizziness; caution in activities requiring alertness.

Adverse Reactions - Common

  • Drowsiness (Common)
  • Dry mouth (Common)
  • Dizziness (Common)

Adverse Reactions - Serious

  • Hypotension (Uncommon)
  • Rebound hypertension if discontinued abruptly (Uncommon)
  • Bradycardia (Uncommon)

Drug-Drug Interactions

  • Additive hypotensive effects with other antihypertensives.
  • Caution with CNS depressants due to increased sedative effects.

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor blood pressure regularly; assess for signs of hypotension.

Diagnoses:

  • Ineffective tissue perfusion related to hypotension.
  • Risk for injury related to dizziness or orthostatic hypotension.

Implementation: Administer as prescribed; advise patient to rise slowly from sitting or lying position.

Evaluation: Evaluate blood pressure control and adverse effects regularly.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Do not stop abruptly to prevent rebound hypertension.
  • Rise slowly from sitting or lying to minimize dizziness.
  • Report symptoms like fainting, excessive dizziness, or symptoms of hypotension.

Special Considerations

Black Box Warnings:

  • Rebound hypertension if discontinued abruptly.

Genetic Factors: N/A

Lab Test Interference: None significant.

Overdose Management

Signs/Symptoms: Severe hypotension, bradycardia, sedation.

Treatment: Supportive care; monitor cardiovascular status; administer vasopressors if needed; gastric lavage may be considered if ingestion is recent.

Storage and Handling

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

Stability: Stable under proper 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.