Acebutolol
Encyclopedia
Acebutolol is a beta blocker
for the treatment of hypertension
and arrhythmias.
). It is therefore more suitable than non cardioselective beta blockers, if a patient with asthma
or chronic obstructive pulmonary disease
(COPD) needs treatment with a beta blocker. (For these reasons, it may be a beta-blocker of choice in inclusion in Polypill
strategies). In doses lower than 800mg daily its constricting effects on the bronchial system and smooth muscle vessels are only 10% to 30% of those observed under propranolol treatment, but there is experimental evidence that the cardioselective properties diminish at doses of 800mg/day or more.
The drug has lipophilic
properties, and therefore crosses the blood-brain barrier
. Acebutolol has no negative impact on serum lipids (cholesterol and triglycerides). No HDL decrease has been observed. In this regard, it is unlike many other beta blockers which have this unfavourable property.
The drug works in hypertensive patients with high, normal, or low renin
plasma concentrations, although acebutolol may be more efficient in patients with high or normal renin plasma concentrations. In clinically relevant concentrations, a membrane-stabilizing effect does not appear to play an important role.
of 3 to 4 hours, and diacetolol a half-life of 8 to 13 hours.
Acebutolol undergoes extensive hepatic metabolization resulting in the desbutyl amine acetolol which is readily converted into diacetolol. Diacetolol is as active as acebutolol (equipotency) and appears to have the same pharmacologic profile. Geriatric patients tend to have higher peak plasma levels of both acebutolol and diacetolol and a slightly prolonged excretion. Excretion is substantially prolonged in patients with renal impairment, and so a dose reduction may be needed. Liver cirrhosis does not seem to alter the pharmacokinetic profile of the parent drug and metabolite.
-like syndrome with skin rash and multiforme organ involvement is even less frequent. The incidence of both ANA and symptomatic disease under acebutolol is higher than under Propranolol. Female patients are more likely to develop these symptoms than male patients. Some few cases of hepatotoxicity with increased liver enzymes (ALT
, AST
) have been seen. Altogether, 5 to 6% of all patients treated have to discontinue acebutolol due to intolerable side effects. When possible, the treatment should be discontinued gradually in order to avoid a withdrawal syndrome with increased frequency of angina and even precipitation of myocardial infarction
.
Beta blocker
Beta blockers or beta-adrenergic blocking agents, beta-adrenergic antagonists, beta-adrenoreceptor antagonists or beta antagonists, are a class of drugs used for various indications. They are particularly for the management of cardiac arrhythmias, cardioprotection after myocardial infarction ,...
for the treatment of hypertension
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
and arrhythmias.
Pharmacology
Acebutolol is a cardioselective beta blocker with ISA (intrinsic sympathomimetic activity; see article on pindololPindolol
Pindolol is a beta blocker....
). It is therefore more suitable than non cardioselective beta blockers, if a patient with asthma
Asthma
Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...
or chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease , also known as chronic obstructive lung disease , chronic obstructive airway disease , chronic airflow limitation and chronic obstructive respiratory disease , is the co-occurrence of chronic bronchitis and emphysema, a pair of commonly co-existing diseases...
(COPD) needs treatment with a beta blocker. (For these reasons, it may be a beta-blocker of choice in inclusion in Polypill
Polypill
A polypill is a medication that is a combination drug of multiple active ingredients, and that is aimed to be consumed widespread in the population, even currently healthy ones, as a means of preventive medicine...
strategies). In doses lower than 800mg daily its constricting effects on the bronchial system and smooth muscle vessels are only 10% to 30% of those observed under propranolol treatment, but there is experimental evidence that the cardioselective properties diminish at doses of 800mg/day or more.
The drug has lipophilic
Lipophilic
Lipophilicity, , refers to the ability of a chemical compound to dissolve in fats, oils, lipids, and non-polar solvents such as hexane or toluene. These non-polar solvents are themselves lipophilic — the axiom that like dissolves like generally holds true...
properties, and therefore crosses the blood-brain barrier
Blood-brain barrier
The blood–brain barrier is a separation of circulating blood and the brain extracellular fluid in the central nervous system . It occurs along all capillaries and consists of tight junctions around the capillaries that do not exist in normal circulation. Endothelial cells restrict the diffusion...
. Acebutolol has no negative impact on serum lipids (cholesterol and triglycerides). No HDL decrease has been observed. In this regard, it is unlike many other beta blockers which have this unfavourable property.
The drug works in hypertensive patients with high, normal, or low renin
Renin
Renin , also known as an angiotensinogenase, is an enzyme that participates in the body's renin-angiotensin system -- also known as the Renin-Angiotensin-Aldosterone Axis -- that mediates extracellular volume , and arterial vasoconstriction...
plasma concentrations, although acebutolol may be more efficient in patients with high or normal renin plasma concentrations. In clinically relevant concentrations, a membrane-stabilizing effect does not appear to play an important role.
Pharmacokinetics
Acebutolol is well absorbed from the GI tract, but undergoes substantial first-pass-metabolization, leading to a bioavailability of only 35% to 50%. Peak plasma levels of acebutolol are reached within 2 to 2.5 hours after oral dosing. Peak levels of the main active metabolite, diacetolol, are reached after 4 hours. Acebutolol has a half-lifeHalf-life
Half-life, abbreviated t½, is the period of time it takes for the amount of a substance undergoing decay to decrease by half. The name was originally used to describe a characteristic of unstable atoms , but it may apply to any quantity which follows a set-rate decay.The original term, dating to...
of 3 to 4 hours, and diacetolol a half-life of 8 to 13 hours.
Acebutolol undergoes extensive hepatic metabolization resulting in the desbutyl amine acetolol which is readily converted into diacetolol. Diacetolol is as active as acebutolol (equipotency) and appears to have the same pharmacologic profile. Geriatric patients tend to have higher peak plasma levels of both acebutolol and diacetolol and a slightly prolonged excretion. Excretion is substantially prolonged in patients with renal impairment, and so a dose reduction may be needed. Liver cirrhosis does not seem to alter the pharmacokinetic profile of the parent drug and metabolite.
Indications
- hypertensionHypertensionHypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
- ventricular and atrial cardiac arrhythmia
- acute myocardial infarction in high-risk patients
- Smith-Magenis syndromeSmith-Magenis syndromeSmith–Magenis Syndrome is a developmental disorder that affects many parts of the body. The major features of this condition include mild to moderate mental retardation, distinctive facial features, sleep disturbances, and behavioral problems...
Contraindications and Precautions
Acebutolol may not be suitable in patients with Asthma bronchiale or COPD due to its bronchoconstricting (β2 antagonistic) effects.Side effects
The development of anti-nuclear antibodies (ANA) has been found in 10 to 30% of patients under treatment with acebutolol. A systemic disease with arthralgic pain and myalgias has been observed in 1%. A lupus erythematosusLupus erythematosus
Lupus erythematosus is a category for a collection of diseases with similar underlying problems with immunity . Symptoms of these diseases can affect many different body systems, including joints, skin, kidneys, blood cells, heart, and lungs...
-like syndrome with skin rash and multiforme organ involvement is even less frequent. The incidence of both ANA and symptomatic disease under acebutolol is higher than under Propranolol. Female patients are more likely to develop these symptoms than male patients. Some few cases of hepatotoxicity with increased liver enzymes (ALT
Alanine transaminase
Alanine transaminase or ALT is a transaminase enzyme . It is also called serum glutamic pyruvic transaminase or alanine aminotransferase ....
, AST
Alanine transaminase
Alanine transaminase or ALT is a transaminase enzyme . It is also called serum glutamic pyruvic transaminase or alanine aminotransferase ....
) have been seen. Altogether, 5 to 6% of all patients treated have to discontinue acebutolol due to intolerable side effects. When possible, the treatment should be discontinued gradually in order to avoid a withdrawal syndrome with increased frequency of angina and even precipitation of myocardial infarction
Myocardial infarction
Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
.