SECTRAL
Clinical safety rating: caution
Comprehensive clinical and safety monograph for SECTRAL (SECTRAL).
Selective beta-1 adrenergic receptor antagonist; negative chronotropic and inotropic effects, reduces cardiac output, decreases renin release.
| Metabolism | Hepatic metabolism via CYP2D6; minor pathways involve conjugation. |
| Excretion | Renal: ~30-40% unchanged; biliary/fecal: ~20-30% as metabolites and parent compound; total renal clearance accounts for 50-70% of elimination. |
| Half-life | Terminal elimination half-life: 8-13 hours; clinically, this supports once-daily dosing, but steady-state is achieved within 2-3 days. |
| Protein binding | ~25-30% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Vd: 1.1-2.6 L/kg; indicates extensive distribution into extravascular tissues. |
| Bioavailability | Oral: 40-70% (average ~50%) due to first-pass metabolism; food does not significantly affect absorption. |
| Onset of Action | Oral: 1-2 hours for beta-blockade effect on heart rate; maximal effect in 2-4 hours. |
| Duration of Action | Duration of beta-blockade: 12-24 hours; clinical effect persists for 24 hours with once-daily dosing, supporting single daily administration. |
| Molecular Weight | 336.43 |
Adult: 200–400 mg orally once daily, initially; may increase to 400–800 mg daily in divided doses (e.g., 200 mg twice daily). Maximum 800 mg/day. Route: Oral.
| Dosage form | CAPSULE |
| Renal impairment | GFR 30–50 mL/min: reduce dose by 25%; GFR 10–29 mL/min: reduce dose by 50%; GFR <10 mL/min: administer 50% of normal dose every 48 hours or 25% every 24 hours. |
| Liver impairment | No specific dosing guidelines for Child-Pugh classification. Use with caution in severe hepatic impairment; consider dose reduction due to reduced clearance. |
| Pediatric use | Not FDA-approved for pediatric use. Limited data: 8–10 mg/kg/day orally in 1–2 divided doses; maximum 400 mg/day. |
| Geriatric use | Start at 200 mg once daily. Increase cautiously due to age-related decline in renal and hepatic function; monitor for bradycardia and hypotension. |
| 1st trimester | Sectral (acebutolol) is a beta-blocker. Use in first trimester is generally avoided unless benefit outweighs risk. May be associated with fetal bradycardia, growth restriction, and hypoglycemia. Category D for hypertension, but cardioselectivity may allow use if necessary. |
| 2nd trimester | During second trimester, continued use may be considered for maternal indications (e.g., hypertension, arrhythmias). Monitor fetal growth and heart rate. Risk of fetal bradycardia, growth restriction, and neonatal hypoglycemia. |
| 3rd trimester | Third trimester use requires caution due to risk of neonatal bradycardia, hypoglycemia, respiratory depression, and low Apgar scores. Beta-blockers may attenuate maternal stress response during labor. Monitor neonate for 24–48 hours after birth. |
Clinical note
Comprehensive clinical and safety monograph for SECTRAL (SECTRAL).
| Placental transfer | Acebutolol crosses the placenta. The cord-to-maternal plasma concentration ratio is approximately 0.3–0.5 for acebutolol and 0.7 for diacetolol. Significant fetal exposure occurs, with potential for pharmacological effects on the fetus. |
■ FDA Black Box Warning
Abrupt discontinuation may exacerbate angina or precipitate myocardial infarction in patients with coronary artery disease.
| Serious Effects |
Hypersensitivity to acebutolol or any component of the formulationSinual bradycardia (heart rate < 45 bpm)Second- or third-degree atrioventricular blockCardiogenic shockDecompensated heart failureSevere peripheral arterial diseaseBronchial asthma (relative to cardioselectivity; may be used with caution)Pheochromocytoma (unless adequately controlled with alpha-blockade)
| Precautions | Cardiogenic shock, sinus bradycardia, heart block greater than first degree, heart failure exacerbation, bronchospasm in asthma/COPD, masking of hypoglycemia, peripheral vascular disease, abrupt withdrawal. |
| Food/Dietary | No significant food interactions reported. Avoid excessive alcohol consumption as it may potentiate hypotensive effects. Grapefruit juice has no known interaction with acebutolol. |
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| Breastfeeding | Acebutolol and its active metabolite diacetolol are excreted into breast milk at low concentrations. The infant dose is estimated at less than 2% of the maternal weight-adjusted dose. However, caution is advised due to potential for bradycardia and hypoglycemia in breastfed infants. Monitor infant for signs of beta-blockade. Use lowest effective maternal dose. Alternative beta-blockers with lower milk transfer (e.g., propranolol) may be preferred. |
| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | First trimester: Limited data; beta-blockers may cause fetal bradycardia, growth restriction, and hypoglycemia. Second and third trimesters: Continued risk of fetal bradycardia, intrauterine growth restriction, and neonatal hypoglycemia; use only if benefit outweighs risk. |
| Fetal Monitoring | Monitor maternal heart rate, blood pressure, and signs of heart failure. Fetal monitoring including heart rate and growth via ultrasound. Neonatal monitoring for bradycardia, hypoglycemia, and respiratory depression after delivery. |
| Fertility Effects | No specific studies; beta-blockers may reduce sperm motility and function in males, and may affect ovulation in females, but clinical significance is unclear. |
| Clinical Pearls | Sectral (acebutolol) is a cardioselective beta-blocker with intrinsic sympathomimetic activity (ISA), making it useful in patients with bradycardia or peripheral vascular disease where non-ISA beta-blockers may be poorly tolerated. It is less likely to cause bronchospasm than non-selective beta-blockers; however, caution is still advised in asthma/COPD due to potential beta-2 blockade at higher doses. Acebutolol reduces blood pressure and heart rate, and is also indicated for ventricular arrhythmias. Its active metabolite, diacetolol, has a longer half-life, allowing once-daily or twice-daily dosing. Monitor heart rate and blood pressure closely; abrupt withdrawal can precipitate angina or myocardial infarction in patients with coronary artery disease. Use with caution in patients with diabetes due to masking of hypoglycemic symptoms. |
| Patient Advice | Take Sectral exactly as prescribed, usually once or twice daily, with or without food. · Do not stop taking this medication abruptly; sudden discontinuation may cause chest pain or heart attack. Your doctor will taper the dose. · This drug may cause dizziness or fatigue; avoid driving or operating machinery until you know how it affects you. · Monitor your heart rate and blood pressure regularly and report significant changes. · Sectral may mask signs of low blood sugar (e.g., rapid heartbeat). Check blood sugar frequently if you have diabetes. · Avoid alcohol as it can increase the blood-pressure-lowering effects and risk of dizziness. · Inform all healthcare providers you are taking Sectral, especially before surgery or dental procedures. · Store at room temperature away from moisture and heat. |