SOTALOL HYDROCHLORIDE
Clinical safety rating: safe
Animal studies have demonstrated safety
Sotalol is a non-selective beta-adrenergic receptor antagonist (beta-blocker) with additional class III antiarrhythmic activity (prolongation of cardiac action potential duration via blockade of potassium channels). It decreases heart rate, myocardial contractility, and AV conduction velocity, and increases ventricular refractoriness.
| Metabolism | Sotalol is not significantly metabolized (<10%) and is primarily excreted unchanged by the kidneys via glomerular filtration and tubular secretion. No major metabolic pathways or CYP450 involvement. |
| Excretion | Renal: 80-90% unchanged via glomerular filtration and tubular secretion; biliary/fecal: <20%. |
| Half-life | Terminal elimination half-life: 10-20 hours in normal renal function; prolonged in renal impairment (up to 40 hours), requiring dose adjustment. |
| Protein binding | <10% bound; minimal binding to serum albumin. |
| Volume of Distribution | 1.5–2.0 L/kg; indicates extensive distribution into tissues, not bound to plasma proteins. |
| Bioavailability | Oral: 90-100% (highly absorbed, minimal first-pass metabolism). |
| Onset of Action | Oral: 2-3 hours; Intravenous: within minutes (peak effect 1-2 hours). |
| Duration of Action | Oral: 12-16 hours (dosed BID); IV: 8-12 hours (continuous infusion for arrhythmia). |
Initial: 80 mg orally twice daily; may increase every 3 days to 160-320 mg/day, maximum 640 mg/day (for life-threatening arrhythmias). Also available as 80 mg intravenous over 20 minutes (1.5 mg/kg) for acute management.
| Dosage form | TABLET |
| Renal impairment | CrCl 30-60 mL/min: administer every 24 hours; CrCl 10-29 mL/min: administer every 36-48 hours; CrCl <10 mL/min: individualize (e.g., every 48-72 hours). |
| Liver impairment | No specific adjustments for Child-Pugh class A or B; use caution in severe hepatic impairment (Child-Pugh class C) due to potential electrolyte disturbances. |
| Pediatric use | Children >2 years: initial 1-2 mg/kg orally twice daily; may titrate to 4-8 mg/kg/day in divided doses, maximum 16 mg/kg/day. For intravenous use: 0.5-1.5 mg/kg over 20 minutes. |
| Geriatric use | Start at lower doses (e.g., 40 mg twice daily) and titrate slowly due to age-related renal function decline and increased risk of bradycardia, QT prolongation, and other adverse effects. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Other drugs that lower heart rate or prolong QT interval can have additive effects Can cause life-threatening ventricular arrhythmias particularly torsades de pointes.
| Breastfeeding | Sotalol is excreted into breast milk with a relatively high milk-to-plasma ratio of approximately 5.6. May cause infant bradycardia, hypoglycemia, and hypotension. Breastfeeding is not recommended during therapy. |
| Teratogenic Risk | Sotalol hydrochloride crosses the placenta. First trimester: limited human data; animal studies show embryo-fetal toxicity at high doses. Second/third trimester: associated with fetal bradycardia, hypoglycemia, and intrauterine growth restriction. Risk of premature labor if used near term. |
■ FDA Black Box Warning
Sotalol can cause life-threatening ventricular tachycardia, including torsade de pointes, especially in patients with reduced renal function, hypokalemia, or if the dose is too high. Initiation or dose increases must be done in a hospital setting with continuous ECG monitoring.
| Common Effects | atrial fibrillation |
| Serious Effects |
["Sinus bradycardia (<50 bpm)","Heart block (second- or third-degree) without pacemaker","Cardiogenic shock","Uncontrolled heart failure","Bronchial asthma or chronic obstructive pulmonary disease with bronchospasm","Prolonged QT interval (baseline QTc >450 ms)","Hypokalemia or hypomagnesemia","Severe renal impairment (CrCl <40 mL/min) unless dose adjusted","Concomitant use with other QT-prolonging drugs (e.g., class I or III antiarrhythmics)"]
| Precautions | ["Proarrhythmic effects: increased risk of torsade de pointes, especially with hypokalemia, bradycardia, or renal impairment","Renal impairment: dose adjustment required based on creatinine clearance","Heart failure: may precipitate or worsen heart failure","Bronchospastic diseases: caution in patients with asthma or COPD","Electrolyte disturbances: correct hypokalemia or hypomagnesemia before use","Abrupt withdrawal: avoid sudden discontinuation in patients with coronary artery disease"] |
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| Fetal Monitoring | Maternal: ECG, heart rate, blood pressure, serum potassium and magnesium, renal function. Fetal: ultrasound for growth, heart rate monitoring for bradycardia. Neonatal: observe for bradycardia, hypoglycemia, respiratory depression for 24-48 hours postpartum. |
| Fertility Effects | No specific human data on fertility impairment. Animal studies have not shown significant adverse effects on fertility. Sotalol may theoretically affect uterine blood flow due to beta-blockade, but clinical significance unknown. |