Acebutolol information from DrugsUpdate
P - Contraindicated in pregnancy
L - Caution when used during lactation
Acebutolol is a beta blocker for the treatment of hypertension and arrhythmias.
Pharmacodynamics
Blocks beta-receptors, primarily affecting heart (slows rate), vascular musculature (decreases BP), and lungs (reduces function).
Pharmacokinetics
Absorption
Well absorbed. T max is 2.5 h (acebutolol) and 3.5 h (diacetolol). Bioavailability is about 40%. Food may decrease the rate of absorption and C max slightly.
Distribution
About 26% protein bound. Hydrophilic (minimally excreted into CSF). Crosses placenta and is excreted in breast milk.
Metabolism
Extensive first-pass hepatic biotransformation. Major metabolite is diacetolol (active; equipotent to acebutolol).
Elimination
T ½ is about 3 to 4 h (acebutolol) and 8 to 13 h (diacetolol). About 30% to 40% eliminated by kidneys, 50% to 60% eliminated by nonrenal mechanisms (ie, bile, feces). Dialyzable.
Acebutolol Adverse Reactions / Acebutolol Side Effects
Cardiovascular
Hypotension; bradycardia; CHF; cold extremities; heart block.
CNS
Insomnia; fatigue; dizziness; depression; lethargy; drowsiness; forgetfulness.
Dermatologic
Rash; hives; fever; alopecia.
EENT
Dry eyes; blurred vision; tinnitus; slurred speech; sore throat.
GI
Nausea; vomiting; diarrhea; dry mouth.
Genitourinary
Impotence; painful, difficult or frequent urination.
Hematologic
Agranulocytosis; thrombocytopenia purpura.
Respiratory
Bronchospasm; dyspnea; wheezing.
Miscellaneous
Weight changes; facial swelling; muscle weakness.
Precautions
Renal Function
Reduction in daily dose is advised.
Hepatic Function
Reduction in daily dose is advised.
Abrupt withdrawal
Abrupt withdrawal is associated with adverse reactions; 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 beta blockers to patients with bronchospastic disease.
Peripheral vascular disease
Acebutolol may precipitate or aggravate symptoms of arterial insufficiency.
Thyrotoxicosis
Acebutolol may mask clinical signs of developing or continuing hyperthyroidism (eg, tachycardia). Abrupt withdrawal may exacerbate symptoms of hyperthyroidism, including thyroid storm.
Other Drug 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.
Dosage
Hypertension
Adults
PO 400 mg daily initially in single or divided doses; usual response range is 200 to 1,200 mg/day.
Elderly
May require lower maintenance doses. Do not exceed 800 mg daily.
Ventricular Arrhythmia
Adults
PO 400 mg (200 mg twice daily); may be titrated up to 1,200 mg daily.
List of Contraindications
Acebutolol and Pregnancy
Category B.
Acebutolol and Lactation
Excreted in breast milk.
Acebutolol and Children
Safety and efficacy not established.
Acebutolol and Other 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.
Storage
Store at room temperature.
Lab interference
Store at room temperature.
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