Acebutolol is a moderately β1-selective adrenoceptor antagonist with intrinsic sympathomimetic activity, first synthesized in 1967. Acebutolol is prepared by chemical synthesis and the racemate is used clinically. It lowers the blood pressure and slows the heart rate. Acebutolol is available for both oral and intravenous use and as an oral combination product with hydrochlorothiazide. Drugs that blocks the β1 receptor have been developed to eliminate the unwanted bronchoconstrictor effects (β2) of propranolol seen among the asthmatic patients. It antagonize β1 receptors at doses 50 to 100 times less than those required to block β2 receptors. This cardioselectivty is more pronounced at low doses and is lost at high doses.
Interactions
Acebutolol is known to interact with other drugs, the details of drug interactions is as follows:DrugDetailsSeverityOnsetManagementAdrenalineAcebutolol may enhance the vasopressor effect of Adrenaline.Epinephrine used as a local anesthetic for dental procedures will not likely cause clinically relevant problems. ModerateImmediateMonitor for increases in pressor effects of Adrenaline if used in patients receiving Acebutolol therapy. Beta1-selective agents should pose limited risk (if used in doses that allow them to retain their selectivity).The amount of Adrenaline used in dental procedures as part of local anesthetic administration is not likely to be of clinical concern.Infiltrating larger volumes of local anesthetics for other surgical procedures (eg, >0.06 mg Adrenaline) may cause clinically-relevant problems.Amiodarone (HCl)Amiodarone may enhance the bradycardic effect of Acebutolol. Possibly to the point of cardiac arrest.MajorMonitor increased signs and symptoms of bradycardia with Acebutolol (possibly to the point of cardiac arrest) if amiodarone is initiated/dose increased, or decreased effects if amiodarone is discontinued/dose decreased. Ophthalmic beta-blockers are likely of little concern.Clonidine (HCl)Acebutolol may enhance the rebound hypertensive effect of Clonidine.This effect can occur when the Clonidine is abruptly withdrawn.MajorRapidIf possible, withdraw the Acebutolol several days before the clonidine is gradually withdrawn.Consider the use of labetalol in place of clonidine, as it has both alpha- and beta-blocking activity. Monitor closely for acute increases in blood pressure. Ophthalmic beta-blockers are likely of little concern. DigoxinAcebutolol may enhance the bradycardic effect of digoxin.ModerateMonitor for increased bradycardia if these two agents are used concomitantly. Ophthalmic beta-blockers are likely of little concern. Diltiazem (HCl)Diltiazem may enhance the hypotensive effect of Acebutolol. Bradycardia and signs of heart failure have also been reported.Diltiazem may decrease the metabolism, via CYP isoenzymes, of Acebutolol. ModerateThough usually safe and effective during concomitant use, monitor for increased evidence of bradycardia, hypotension, or signs of heart failure during concomitant use of Acebutolol and Diltiazem.Ophthalmic beta-blockers are likely of little concern.IndacaterolBeta-blockers may exacerbate bronchospasms in patients with COPD.monitor closelyIoxaglateLimited data suggest that patients receiving beta blockers may have an increased risk of severe hypotensive and/or hypersensitivity reactions to parenteral iodinated contrast media. In addition, the treatment of allergic/anaphylactoid reactions in these patients may be more difficult. The mechanism is unknown. ModeratePatients who have received beta blockers should be closely monitored for adverse reactions to iodinated contrast media. If anaphylaxis occurs, clinicians should be aware that beta blockers may attenuate the response to epinephrine. Thus, larger doses of epinephrine may be necessary to overcome the bronchospasm, although such large doses can also cause excessive alpha adrenergic stimulation resulting in hypertension, reflex bradycardia, heart block, and possible potentiation of bronchospasm. Alternative treatments recommended include vigorous supportive care (e.g., fluids) and the use of parenteral beta agonists for bronchospasm and norepinephrine for hypotension.IpodateLimited data suggest that patients receiving beta blockers may have an increased risk of severe hypotensive and/or hypersensitivity reactions to parenteral iodinated contrast media. In addition, the treatment of allergic/anaphylactoid reactions in these patients may be more difficult. The mechanism is unknown. ModeratePatients who have received beta blockers should be closely monitored for adverse reactions to iodinated contrast media. If anaphylaxis occurs, clinicians should be aware that beta blockers may attenuate the response to epinephrine. Thus, larger doses of epinephrine may be necessary to overcome the bronchospasm, although such large doses can also cause excessive alpha adrenergic stimulation resulting in hypertension, reflex bradycardia, heart block, and possible potentiation of bronchospasm. Alternative treatments recommended include vigorous supportive care (e.g., fluids) and the use of parenteral beta agonists for bronchospasm and norepinephrine for hypotension.MetrizamideLimited data suggest that patients receiving beta blockers may have an increased risk of severe hypotensive and/or hypersensitivity reactions to parenteral iodinated contrast media. In addition, the treatment of allergic/anaphylactoid reactions in these patients may be more difficult. The mechanism is unknown. MajorPatients who have received beta blockers should be closely monitored for adverse reactions to iodinated contrast media. If anaphylaxis occurs, clinicians should be aware that beta blockers may attenuate the response to epinephrine. Thus, larger doses of epinephrine may be necessary to overcome the bronchospasm, although such large doses can also cause excessive alpha adrenergic stimulation resulting in hypertension, reflex bradycardia, heart block, and possible potentiation of bronchospasm. Alternative treatments recommended include vigorous supportive care (e.g., fluids) and the use of parenteral beta agonists for bronchospasm and norepinephrine for hypotension.Phenylephrine (HCl)Phenylpropanolamine (HCl)PropylthiouracilHyperthyroidism may cause an increased clearance of beta blockers with a high extraction ratio. A dose reduction of beta-adrenergic blockers may be needed when a hyperthyroid patient becomes euthyroid.Verapamil (HCl)Verapamil may enhance the hypotensive effect of Acebutolol. Bradycardia and signs of heart failure have also been reported. Verapamil may decrease the metabolism, via CYP isoenzymes, of Acebutolol.ModerateManagement Though usually safe and effective during concomitant use, monitor for increased evidence of bradycardia, hypotension, or signs of heart failure during concomitant use of beta-blockers and nondihydropyridine calcium channel blockers. Ophthalmic beta-blockers are likely of little concern. Though usually safe and effective during concomitant use, monitor for increased evidence of bradycardia, hypotension, or signs of heart failure during concomitant use of Acebutolol and Verapamil. Ophthalmic beta-blockers are likely of little concern. These interactions are sometimes beneficial and sometimes may pose threats to life. Always consult your physician for the change of dose regimen or an alternative drug of choice that may strictly be required.