Acebutolol HCl

 Action Blocks beta-receptors, primarily affecting heart (slows rate), vascular musculature (decreases BP) and lungs (reduces function).

 Indications Management of hypertension and premature ventricular contractions.

 Contraindications Hypersensitivity to beta-blockers; persistently severe bradycardia; greater than first-degree heart block; CHF, unless secondary to tachyarrhythmia treatable with beta-blockers; overt cardiac failure; sinus bradycardia; cardiogenic shock.

 Route/Dosage

Hypertension

ADULTS: PO 400 mg qd initially in single or divided doses; usual response range is 200 to 1200 mg/day. ELDERLY PATIENTS: May require lower maintenance doses. Do not exceed 800 mg qd.

Ventricular Arrhythmia

ADULTS: PO 400 mg (200 mg bid); may be titrated up to 1200 mg qd.

 Interactions

Clonidine: May enhance or reverse acebutolol's antihypertensive effect; potentially life-threatening situations may occur, especially on withdrawal. NSAIDs: Some agents may impair antihypertensive effect. Prazosin: May cause increase in orthostatic hypotension. Verapamil: Effects of both drugs may be increased.

 Lab Test Interferences Antinuclear antibodies may develop; usually reversible on discontinuation. Acebutolol may interfere with glucose or insulin tolerance tests. May cause changes in serum lipids.

 Adverse Reactions

CV: Hypotension; bradycardia; CHF; cold extremities; heart block. RESP: Bronchospasm; dyspnea; wheezing. CNS: Insomnia; fatigue; dizziness; depression; lethargy; drowsiness; forgetfulness. EENT: Dry eyes; blurred vision; tinnitus; slurred speech; sore throat. GI: Nausea; vomiting; diarrhea; dry mouth. GU: Impotence; painful, difficult or frequent urination. HEMA: Agranulocytosis; thrombocytopenia purpura. DERM: Rash; hives; fever; alopecia. OTHER: Weight changes; facial swelling; muscle weakness.

 Precautions

Pregnancy: Category B. Lactation: Excreted in breast milk. Abrupt withdrawal: Associated with adverse effects; gradually decrease dose over 1 to 2 wk. Anaphylaxis: Serious reactions may occur; aggressive therapy may be required. CHF: Administer cautiously in patients taking digitalis and diuretics for CHF. Diabetes: Acebutolol may mask signs of hypoglycemia (eg, tachycardia, BP changes). May potentiate insulin-induced hypoglycemia. Nonallergic bronchospasm (eg, chronic bronchitis, emphysema): In general, do not give betablockers to patients with bronchospastic disease. Peripheral vascular disease: Acebutolol may precipitate or aggravate symptoms of arterial insufficiency. Renal/hepatic function impairment: Reduction in daily dose is advised. Thyrotoxicosis: Acebutolol may mask clinical signs of developing or continuing hyperthyroidism (eg, tachycardia). Abrupt withdrawal may exacerbate symptoms of hyperthyroidism, including thyroid storm.

 Administration/Storage

• Before giving initial dose, take patient's pulse. If pulse is < 60 bpm, do not administer medication; notify physician.
• During initial phase of therapy, continue taking patient's pulse before administering each dose. After initial phase, take pulse before first dose of day and measure BP twice weekly.
• Store at room temperature.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies.
• Monitor serum lipid levels and thyroid function.
• Assess for signs of CHF (eg, shortness of breath, edema, decreased output) or respiratory involvement (eg, dyspnea, cough); if present, withhold drug and notify physician.

 Patient/Family Education

• Teach patient to take pulse every day and record. If < 60 bpm, tell not to take medication and to notify physician.
• Instruct diabetic patients to monitor blood sugar level every 6 hr. Drug may mask symptoms of hypoglycemia.
• Caution patient not to stop taking drug suddenly since doing so may exacerbate angina and increase possibility of MI.
• Explain that drug may cause dizziness. Advise patient to avoid sudden position changes to prevent orthostatic hypotension.
• 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 any otc medications without consulting physician.