Acebutolol (sectral) - a cardioselective beta-blocker

Acebutolol is a selective beta-blocker with intrinsic sympathomimetic activity.

Thus, it is a preferred beta-blocker in patients with Asthma and Chronic obstructive pulmonary diseases.

It is primarily used to treat Hypertension, arrhythmias and angina pectoris.

Other selective beta-blockers commonly used are bisoprolol, atenolol, and carvedilol.

In cases of severe heart failure, obvious bradycardia, second- and third-degree heart blocks, and cardiogenic shock, beta-blockers should be avoided.

Acebutolol and alcohol:

  • It increases the CNS depressant effects of alcohol.
  • Patients may feel drowsy, dizzy, and become stuporous when taking alcohol while on acebutolol.

Acebutolol Overdose:

  • It is considered as one of the most toxic beta-blockers.
  • Significant QT prolongation and ventricular repolarization that is not usually seen with propranolol overdose have been reported. Acebutolol has resulted in deaths.
  • It is therefore not used commonly in clinical practice. 

Acebutolol Dosage in Angina and ventricular arrhythmias: 

  • Initially, 400 mg/day orally in 2 divided doses.
  • The maintenance dose is 600-1200 mg/day in divided doses
  • The maximum dose is 1200 mg/day

Acebutolol dosage in Hypertension: 

  • Oral: 400-800 mg/day
  • The maximum dose: 1200 mg/day

Dosage in Chronic stable angina (unlabeled use): 

  • Oral: Usual dose: 400-1200 mg/day in 2 divided doses.

Acebutolol Dosage in renal disease:

Creatinine clearance of  25-49 mL/minute:

  • Reduce dose by 50%.

Creatinine clearance of <25 mL/minute:

  • Reduce dose by 75%.

Dose in Liver disease:

  • Although the manufacturer does not provide dose adjustment in liver disease but it should be used with caution.

How to administer Acebutolol?

  • It may be administered without regard to meals. 

Pregnancy Risk Factor: C

Pregnancy Implications:

  • Acebutolol crosses the placenta. Beta-blockers can cause fetal or neonatal bradycardia and hypoglycemia as well as respiratory depression, intrauterine Growth Restriction (IUGR), and small placentas.
  • Additionally, pregnant women have a longer half-life for acebutolol. T
  • his is a pregnancy-class C drug, so other agents may be better for hypertensive women.

Use during lactation:

  • It is found in breast milk and is not usually recommended during breastfeeding. 

Side effects of Acebutolol (Sectral):

  • It can cause fatigue, edema, bradycardia, hypotension and congestive heart failure.
  • It has also been associated with depression, abnormal dreams, dizziness, rash, and pruritis.
  • Gastrointestinal adverse effects include diarrhea or constipation, nausea, flatulence, abdominal pain, and vomiting.
  • Beta-blockers can cause impotence, myalgias, cough, wheezing, pharyngitis and intermittent claudication.
  • Patients with diabetes should use beta-blockers with caution since they can disguise the symptoms of hypoglycemia.
  • Additionally, it should not be used by people who have Raynaud's syndrome or peripheral arterial disease because it worsens their condition by generating peripheral vasoconstriction.

Mechanism of Action of Acebutolol:

  • It competes with both beta 1 and beta 2 adrenergic receptors, although except in large dosages, it has little to no effect on beta 2.
  • It contains intrinsic sympathomimetic and membrane-stabilizing properties.
  • While beta-2 receptors are prevalent in the airways, beta-1 receptors are largely found in the heart and blood vessels.
  • Non-selective beta-blockers inhibit the beta-receptors in the airways and may result in life-threatening asthma.

Onset of action is 1-2 hours

Duration of action is 12-24 hours

Up to 40% of the drug is absorbed when taken orally.

Time to peak action is 2-4 hours.

Excretion of acebutolol:

  • 50% to 60% of it is excreted in the feces; 30% to 40% in the urine; the active metabolite is primarily excreted via urine.

Acebutolol Brand names:

  • Acebutolol
  • Rhotral
  • Sectral

It is not available in Pakistan.

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