Get your patient on Acebutolol Hydrochloride - Acebutolol Hydrochloride capsule (Acebutolol Hydrochloride)
Acebutolol Hydrochloride - Acebutolol Hydrochloride capsule prescribing information
INDICATIONS AND USAGE
Hypertension
Acebutolol hydrochloride capsules are indicated for the management of hypertension in adults. It may be used alone or in combination with other antihypertensive agents, especially thiazide-type diuretics.
Ventricular Arrhythmias
Acebutolol hydrochloride capsules are indicated in the management of ventricular premature beats; it reduces the total number of premature beats, as well as the number of paired and multiform ventricular ectopic beats, and R-on-T beats.
DOSAGE AND ADMINISTRATION
Hypertension
The initial dosage of acebutolol in uncomplicated mild-to-moderate hypertension is 400 mg. This can be given as a single daily dose, but in occasional patients twice daily dosing may be required for adequate 24-hour blood-pressure control. An optimal response is usually achieved with dosages of 400 mg to 800 mg per day, although some patients have been maintained on as little as 200 mg per day. Patients with more severe hypertension or who have demonstrated inadequate control may respond to a total of 1200 mg daily (administered b.i.d.), or to the addition of a second antihypertensive agent. Beta-1 selectivity diminishes as dosage is increased.
Ventricular Arrhythmia
The usual initial dose of acebutolol is 400 mg daily given as 200 mg b.i.d. Dosage should be increased gradually until an optimal clinical response is obtained, generally at 600 to 1200 mg per day. If treatment is to be discontinued, the dosage should be reduced gradually over a period of about two weeks.
Use in Older Patients
Older patients have an approximately 2-fold increase in bioavailability and may require lower maintenance doses. Doses above 800 mg/day should be avoided in the elderly.
CONTRAINDICATIONS
Acebutolol hydrochloride is contraindicated in: 1) persistently severe bradycardia; 2) second- and third-degree heart block; 3) overt cardiac failure; and 4) cardiogenic shock (see WARNINGS ).
ADVERSE REACTIONS
Acebutolol is well tolerated in properly selected patients. Most adverse reactions have been mild, not required discontinuation of therapy, and tended to decrease as duration of treatment increases.
The following table shows the frequency of treatment-related side effects derived from controlled clinical trials in patients with hypertension, angina pectoris, and arrhythmia. These patients received acebutolol, propranolol, or hydrochlorothiazide as monotherapy, or placebo.
| TOTAL VOLUNTEERED AND ELICITED (U.S. STUDIES) | ||||
| Body System/ Adverse Reaction | Acebutolol (N=1002) % | Propranolol (N=424) % | Hydrochlorthiazide (n=178) % | Placebo (N=314) % |
| Cardiovascular | ||||
| Chest Pain | 2 | 4 | 4 | 1 |
| Edema | 2 | 2 | 4 | 1 |
| Central Nervous System | ||||
| Depression | 2 | 1 | 3 | 1 |
| Dizziness | 6 | 7 | 12 | 2 |
| Fatigue | 11 | 17 | 10 | 4 |
| Headache | 6 | 9 | 13 | 4 |
| Insomnia | 3 | 6 | 5 | 1 |
| Abnormal dreams | 2 | 3 | 0 | 1 |
| Dermatologic | ||||
| Rash | 2 | 2 | 4 | 1 |
| Gastrointestinal | ||||
| Constipation | 4 | 2 | 7 | 0 |
| Diarrhea | 4 | 5 | 5 | 1 |
| Dyspepsia | 4 | 6 | 3 | 1 |
| Flatulence | 3 | 4 | 7 | 1 |
| Nausea | 4 | 6 | 3 | 0 |
| Genitourinary | ||||
| Micturition (frequency) | 3 | 1 | 9 | < 1 |
| Musculoskeletal | ||||
| Arthralgia | 2 | 1 | 3 | 2 |
| Myalgia | 2 | 1 | 4 | 0 |
| Respiratory | ||||
| Cough | 1 | 1 | 2 | 0 |
| Dyspnea | 4 | 6 | 4 | 2 |
| Rhinitis | 2 | 1 | 4 | < 1 |
| Special Senses | ||||
| Abnormal Vision | 2 | 2 | 3 | 0 |
The following selected (potentially important) side effects were seen in up to 2% of acebutolol patients:
Cardiovascular: hypotension, bradycardia, heart failure.
Central Nervous System: anxiety, hyper/hypoesthesia, impotence.
Dermatological: pruritus.
Gastrointestinal: vomiting, abdominal pain.
Genitourinary: dysuria, nocturia.
Liver and Biliary System: A small number of cases of liver abnormalities (increased SGOT, SGPT, LDH) have been reported in association with acebutolol therapy. In some cases increased bilirubin or alkaline phosphatase, fever, malaise, dark urine, anorexia, nausea, headache, and/or other symptoms have been reported. In some of the reported cases, the symptoms and signs were confirmed by rechallenge with acebutolol. The abnormalities were reversible upon cessation of acebutolol therapy.
Musculoskeletal: back pain, joint pain.
Respiratory: pharyngitis, wheezing.
Special Senses: conjunctivitis, dry eye, eye pain.
Autoimmune: In extremely rare instances, systemic lupus erythematosus has been reported.
The incidence of drug-related adverse effects (volunteered and solicited) according to acebutolol dose is shown below. (Data from 266 hypertensive patients treated for 3 months on a constant dose.)
Body System | 400 mg/day (N=132) | 800 mg/day (N=63) | 1200 mg/day (N=71) |
| Cardiovascular | 5% | 2% | 1% |
| Gastrointestinal | 3% | 3% | 1% |
| Musculoskeletal | 2% | 3% | 4% |
| Central Nervous system | 9% | 13% | 17% |
| Respiratory | 1% | 5% | 6% |
| Skin | 1% | 2% | 1% |
| Special Senses | 2% | 2% | 6% |
| Genitourinary | 2% | 3% | 1% |
Potential Adverse Events
In addition, certain adverse effects not listed above have been reported with other β-blocking agents and should also be considered as potential adverse effects of acebutolol.
Central Nervous System: Reversible mental depression progressing to catatonia (an acute syndrome characterized by disorientation for time and place), short-term memory loss, emotional lability, slightly clouded sensorium, and decreased performance (neuropsychometrics).
Cardiovascular: Intensification of AV block (see CONTRAINDICATIONS ).
Allergic: Erythematous rash, fever combined with aching and sore throat, laryngospasm, and respiratory distress.
Hematologic: Agranulocytosis, nonthrombocytopenic, and thrombocytopenic purpura.
Gastrointestinal: Mesenteric arterial thrombosis and ischemic colitis.
Miscellaneous: Reversible alopecia and Peyronie’s disease. The oculomucocutaneous syndrome associated with the β-blocker practolol has not been reported with acebutolol during investigational use and extensive foreign clinical experience.
DESCRIPTION
Acebutolol hydrochloride, USP is a selective, hydrophilic beta-adrenoreceptor blocking agent with mild intrinsic sympathomimetic activity for use in treating patients with hypertension and ventricular arrhythmias. It is marketed in capsule form for oral administration. Acebutolol hydrochloride capsules, USP are provided in two dosage strengths which contain 200 mg or 400 mg of acebutolol as the hydrochloride salt. The inactive ingredients present are D&C Red 28, D&C Yellow 10, FD&C Blue 1, FD&C Red 40, gelatin, maize starch, povidone, stearic acid and titanium dioxide.
Acebutolol hydrochloride, USP has the following structural formula:
C 18 H 28 N 2 O 4 •HCl M.W. 372.89
Acebutolol hydrochloride, USP is a white or slightly off-white powder freely soluble in water, and less soluble in alcohol. Chemically it is defined as the hydrochloride salt of (±) N-[3-Acetyl-4-[2-hydroxy-3-[(1-methylethyl) amino]propoxy]phenyl] butanamide.
CLINICAL PHARMACOLOGY
Acebutolol is a cardioselective, β-adrenoreceptor blocking agent, which possesses mild intrinsic sympathomimetic activity (ISA) in its therapeutically effective dose range.
Pharmacodynamics
β 1 -cardioselectivity has been demonstrated in experimental animal studies. In anesthetized dogs and cats, acebutolol is more potent in antagonizing isoproterenol-induced tachycardia (β 1 ) than in antagonizing isoproterenol-induced vasodilatation (β 2 ). In guinea pigs and cats, it is more potent in antagonizing this tachycardia than in antagonizing isoproterenol-induced bronchodilatation (β 2 ). ISA of acebutolol has been demonstrated in catecholamine-depleted rats by tachycardia induced by intravenous administration of this agent. A membrane-stabilizing effect has been detected in animals, but only with high concentrations of acebutolol.
Clinical studies have demonstrated β 1 -blocking activity at the recommended doses by: a) reduction in the resting heart rate and decrease in exercise-induced tachycardia; b) reduction in cardiac output at rest and after exercise; c) reduction of systolic and diastolic blood pressures at rest and post exercise; d) inhibition of isoproterenol-induced tachycardia.
The β 1 -selectivity of acebutolol has also been demonstrated on the basis of the following vascular and bronchial effects:
Vascular Effects: Acebutolol has less antagonistic effects on peripheral vascular β 2 -receptors at rest and after epinephrine stimulation than nonselective β-antagonists.
Bronchial Effects: In single-dose studies in asthmatics examining effects of various beta-blockers on pulmonary function, low doses of acebutolol produce less evidence of bronchoconstriction and less reduction of beta 2 agonist, bronchodilating effects, than nonselective agents like propranolol but more than atenolol.
ISA has been observed with acebutolol in man, as shown by a slightly smaller (about 3 beats per minute) decrease in resting heart rate when compared to equivalent β-blocking doses of propranolol, metoprolol or atenolol. Chronic therapy with acebutolol induced no significant alteration in the blood lipid profile.
Acebutolol has been shown to delay AV conduction time and to increase the refractoriness of the AV node without significantly affecting sinus node recovery time, atrial refractory period, or the HV conduction time. The membrane-stabilizing effect of acebutolol is not manifest at the doses used clinically.
Significant reductions in resting and exercise heart rates and systolic blood pressures have been observed 1.5 hours after acebutolol administration with maximal effects occurring between 3 and 8 hours post-dosing in normal volunteers. Acebutolol has demonstrated a significant effect on exercise-induced tachycardia 24 to 30 hours after drug administration.
There are significant correlations between plasma levels of acebutolol and both the reduction in resting heart rate and the percent of β-blockade of exercise-induced tachycardia.
The antihypertensive effect of acebutolol has been shown in double-blind controlled studies to be superior to placebo and similar to propranolol and hydrochlorothiazide. In addition, patients responding to acebutolol administered twice daily had a similar response whether the dosage regimen was changed to once daily administration or continued on a b.i.d. regimen. Most patients responded to 400 mg to 800 mg per day in divided doses.
The antiarrhythmic effect of acebutolol was compared with placebo, propranolol, and quinidine. Compared with placebo, acebutolol significantly reduced mean total ventricular ectopic beats (VEB), paired VEB, multiform VEB, R-on-T beats, and ventricular tachycardia (VT). Both acebutolol and propranolol significantly reduced mean total and paired VEB and VT. Acebutolol and quinidine significantly reduced resting total and complex VEB; the antiarrhythmic efficacy of acebutolol was also observed during exercise.
Pharmacokinetics and Metabolism
Acebutolol is well absorbed from the GI tract. It is subject to extensive first-pass hepatic biotransformation, with an absolute bioavailability of approximately 40% for the parent compound. The major metabolite, an N-acetyl derivative (diacetolol), is pharmacologically active. This metabolite is equipotent to acebutolol and in cats is more cardioselective than acebutolol; therefore, this first-pass phenomenon does not attenuate the therapeutic effect of acebutolol. Food intake does not have a significant effect on the area under the plasma concentration-time curve (AUC) of acebutolol although the rate of absorption and peak concentration decreased slightly.
The plasma elimination half-life of acebutolol is approximately 3 to 4 hours, while that of its metabolite, diacetolol, is 8 to 13 hours. The time to reach peak concentration for acebutolol is 2.5 hours and for diacetolol, after oral administration of acebutolol, 3.5 hours.
Within the single oral dose range of 200 mg to 400 mg, the kinetics are dose proportional. However, this linearity is not seen at higher doses, probably due to saturation of hepatic biotransformation sites. In addition, after multiple dosing the lack of linearity is also seen by AUC increases of approximately 100% as compared to single oral dosing. Elimination via renal excretion is approximately 30% to 40% and by nonrenal mechanisms 50% to 60%, which includes excretion into the bile and direct passage through the intestinal wall.
Acebutolol has a low binding affinity for plasma proteins (about 26%). Acebutolol and its metabolite, diacetolol, are relatively hydrophilic and, therefore, only minimal quantities have been detected in the cerebrospinal fluid (CSF).
Drug interaction studies with tolbutamide and warfarin indicated no influence on the therapeutic effects of these compounds. Digoxin and hydrochlorothiazide plasma levels were not affected by concomitant acebutolol administration. The kinetics of acebutolol were not significantly altered by concomitant administration of hydrochlorothiazide, hydralazine, sulfinpyrazone, or oral contraceptives.
In patients with renal impairment, there is no effect on the elimination half-life of acebutolol, but there is decreased elimination of the metabolite, diacetolol, resulting in a two- to three-fold increase in its half-life. For this reason, the drug should be administered with caution in patients with renal insufficiency (see PRECAUTIONS ). Acebutolol and its major metabolite are dialyzable.
Acebutolol crosses the placental barrier and is secreted in breast milk.
In geriatric patients, the bioavailability of acebutolol and its metabolite is increased, approximately two-fold, probably due to decreases in the first-pass metabolism and renal function in the elderly.
HOW SUPPLIED
Acebutolol hydrochloride capsules, USP are available as follows:
200 mg: Hard gelatin capsules with bright orange opaque body printed radially “669” with black ink and lavender opaque cap printed radially “AMNEAL” with black ink, which contains white granular powder.
Bottles of 100 NDC 53746-669-01 Bottles of 500 NDC 53746-669-05
400 mg: Hard gelatin capsules with bright orange opaque body printed radially “670” with black ink and lavender opaque cap printed radially “AMNEAL” with black ink, which contains white granular powder.
Bottles of 30 NDC 53746-670-30 Bottles of 100 NDC 53746-670-01 Bottles of 500 NDC 53746-670-05
Keep tightly closed.
Store at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature].
Protect from light. Dispense in a tight, light-resistant container.
Manufactured by: Amneal Pharmaceuticals Pvt. Ltd. Oral Solid Dosage Unit Ahmedabad, 382213 INDIA
Distributed by: Amneal Pharmaceuticals LLC Bridgewater, NJ 08807
Rev. 10-2024-01
