Overview
11 DESCRIPTION Sotalol hydrochloride tablets, USP contain sotalol hydrochloride USP, an antiarrhythmic drug with Class II (beta-adrenoreceptor blocking) and Class III (cardiac action potential duration prolongation) properties. Sotalol hydrochloride tablets, USP are supplied as a light-blue, capsule-shaped tablet for oral administration.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Sotalol has both beta-adrenoreceptor blocking (Vaughan Williams Class II) and cardiac action potential duration prolongation (Vaughan Williams Class III) antiarrhythmic properties. The two isomers of sotalol have similar Class III antiarrhythmic effects, while the l-isomer is responsible for virtually all of the beta-blocking activity. The beta-blocking effect of sotalol is non-cardioselective, half maximal at about 80 mg/day and maximal at doses between 320 and 640 mg/day. Sotalol does not have partial agonist or membrane stabilizing activity. Although significant beta-blockade occurs at oral doses as low as 25 mg, significant Class III effects are seen only at daily doses of 160 mg and above.
Indications
- 1 INDICATIONS AND USAGE Sotalol hydrochloride tablets are an antiarrhythmic indicated for: the treatment of life-threatening ventricular arrhythmias ( 1.1 ) the maintenance of normal sinus rhythm in patients with atrial fibrillation or flutter (AFIB/AFL) ( 1.2 ) Limitations of Use Sotalol hydrochloride tablets have not been shown to enhance survival in patients with life-threatening ventricular arrhythmias ( 1.1 ) Avoid use in patients with minimally symptomatic or easily reversible AFIB/AFL ( 1.2 ) 1.
Common Doses
- 80 mg
- 320 mg
- 640 mg
- 120 mg
Dosage
2 DOSAGE AND ADMINISTRATION Sotalol hydrochloride tablets: Initial dosage in adults is 80 mg twice daily. Increase the dose as needed in increments of 80 mg/day, every 3 days to a maximum 320 mg total daily dose ( 2.2 ) Pediatrics: Dosage depends on age ( 2.4 ) 2.1 General Safety Measures for Initiation of Oral Sotalol Therapy Withdraw other antiarrhythmic therapy before starting sotalol hydrochloride tablets and monitor for a minimum of 2 to 3 plasma half-lives prior to initiating sotalol hydrochloride tablets therapy if the patient's clinical condition permits [see Drug Interactions ( 7 )] .
Black Box Warning
WARNING: LIFE-THREATENING PROARRHYTHMIA To minimize the risk of drug-induced arrhythmia, initiate or reinitiate oral sotalol in a facility that can provide cardiac resuscitation and continuous electrocardiographic monitoring. Sotalol can cause life-threatening ventricular tachycardia associated with QT interval prolongation. If the QT interval prolongs to 500 msec or greater, reduce the dose, lengthen the dosing interval, or discontinue the drug. Calculate creatinine clearance to determine appropriate dosing [see Dosage and Administration ( 2.5 )] .
Contraindications
- 4 CONTRAINDICATIONS Sotalol hydrochloride tablets are contraindicated in patients with: Sinus bradycardia, sick sinus syndrome, second and third degree AV block, unless a functioning pacemaker is present Congenital or acquired long QT syndromes Cardiogenic shock or decompensated heart failure Serum potassium 450 msec For the treatment of AFIB/AFL or ventricular arrythmias Sinus bradycardia, 2 nd or 3 rd degree AV block, sick sinus syndrome ( 4 ) Congenital or acquired long QT syndrome ( 4 ) Serum potassium 450 msecs ( 4 )
Side Effects
- 6 ADVERSE REACTIONS The most common adverse reactions (≥2%) for sotalol hydrochloride are: fatigue 4%, bradycardia (less than 50 bpm) 3%, dyspnea 3%, proarrhythmia 3%, asthenia 2%, and dizziness 2%. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Oxford Pharmaceuticals at 844-508-1455, 8:00 am - 4:30 pm ET, Monday – Friday or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical...
Interactions
- 7 DRUG INTERACTIONS Class I or III Antiarrhythmics or other drugs that prolong the QT interval: Avoid concomitant use ( 7.1 ) Digoxin, calcium channel blocker: increased risk of bradycardia, hypotension, heart failure ( 7.2 ) Dosage of insulin or antidiabetic drugs may need adjustment ( 7.4 ) Aluminum- or magnesium-based antacids reduce sotalol exposure ( 7.7 ) 7.1 Antiarrhythmics and Other QT Prolonging Drugs Discontinue Class I or Class III antiarrhythmic agents for at least three half-lives prior to dosing with sotalol.