Guanabenz Acetate

A to Z Drug Facts

 Action Appears to stimulate central alpha₂-adrenergic receptors, inhibiting sympathetic outflow from brain to peripheral circulation.

 Indications Treatment of hypertension alone or with a thiazide diuretic.

 Contraindications Standard considerations.

 Route/Dosage

ADULTS: PO 4 mg bid initially; may increase by 4 to 8 mg daily every 1 to 2 wk; maximum dose 32 mg bid.

 Interactions

CNS depressants: Increased sedation.

 Lab Test Interferences None well documented.

 Adverse Reactions

CV: Chest pain; edema; arrhythmias; palpitations; atrioventricular dysfunction. CNS: Drowsiness; sedation; dizziness; anxiety; ataxia; depression; sleep disturbances. DERM: Rash; pruritus. EENT: Blurred vision; nasal congestion. GI: Dry mouth; constipation; diarrhea; nausea; vomiting; abdominal discomfort. GU: Urinary frequency; disturbances of sexual function. HEPA: Increased liver enzymes. RESP: Dyspnea. OTHER: Gynecomastia; muscle or joint pain; weakness; taste disorders.

 Precautions

Pregnancy: Category C. Lactation: Undetermined. Children: Safety and efficacy in children < 12 yr not established. Special risk patients: Use with caution in patients with severe coronary insufficiency, recent MI, or cerebrovascular disease. Sedation: Occurs in large percentage of patients. Withdrawal: Do not discontinue therapy without consulting health care provider; drug must be withdrawn gradually to avoid rapid rise in BP.

 Administration/Storage

• Administer with food or milk.
• Store in tightly closed container in cool environment.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies. Note any cardiovascular or cerebrovascular disease.
• Take patient's BP (lying, sitting, standing) and pulse before administering drug. Monitor periodically throughout therapy.
• Assess for dry mouth and follow treatment measures as necessary.
• Report these signs to health care provider immediately: Hypotension, chest pain, arrhythmias, edema, dyspnea.

 Patient/Family Education

• Instruct patient and family member in proper technique for taking BP. Advise patient to check and record BP weekly.
• Advise patient to lie down if dizziness or blurred vision occurs.
• Explain that impotence may occur but is reversible. Tell patient to report to health care provider.
• Instruct patient not to discontinue drug abruptly.
• Counsel patient about benefits of weight reduction, exercise, reduction of alcohol and sodium, cessation of smoking.
• Instruct patient to report these symptoms to health care provider: Headache, dizziness, weakness, blurred vision.
• Advise patient to take sips of water frequently, suck on ice chips or sugarless hard candy, or chew sugarless gum if dry mouth occurs.
• Caution patient to avoid sudden position changes to prevent orthostatic hypotension.
• Instruct patient to avoid intake of alcoholic beverages or other CNS depressants.
• Advise patient that drug may cause drowsiness and to use caution while driving or performing other tasks requiring mental alertness.
• Instruct patient not to take otc medications without consulting health care provider.

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Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts