DOSAGE AND ADMINISTRATION
As with other antiarrhythmic agents, Sorine® (Sotalol HCl) Tablets should be initiated and doses increased in a hospital with facilities for cardiac rhythm monitoring and assessment (see INDICATIONS AND USAGE). Sorine® should be administered only after appropriate clinical assessment (see INDICATIONS AND USAGE), and the dosage of Sorine® must be individualized for each patient on the basis of therapeutic response and tolerance. Proarrhythmic events can occur not only at initiation of therapy, but also with each upward dosage adjustment.
Adults: Dosage of Sorine® should be adjusted gradually, allowing 3 days between dosing increments in order to attain steady-state plasma concentrations, and to allow monitoring of QT intervals. Graded dose adjustment will help prevent the usage of doses which are higher than necessary to control the arrhythmia. The recommended initial dose is 80 mg twice daily. This dose may be increased, if necessary, after appropriate evaluation to 240 or 320 mg/day (120 to 160 mg twice daily). In most patients, a therapeutic response is obtained at a total daily dose of 160 to 320 mg/day, given in two or three divided doses. Some patients with life-threatening refractory ventricular arrhythmias may require doses as high as 480 to 640 mg/day; however, these doses should only be prescribed when the potential benefit outweighs the increased risk of adverse events, in particular proarrhythmia. Because of the long terminal elimination half-life of sotalol, dosing on more than a BID regimen is usually not necessary.
Pediatrics: Pediatric dosing information for sotalol hydrochloride tablets is approved for Berlex Laboratories' sotalol hydrochloride tablets. However, due to Berlex's marketing exclusivity rights, this drug product is not labeled for pediatric use.
Dosage in Renal Impairment
Adults: Because sotalol is excreted predominantly in urine and its terminal elimination half-life is prolonged in conditions of renal impairment, the dosing interval (time between divided doses) of Sorine® (Sotalol HCl) Tablets should be modified (when creatinine clearance is lower than 60 mL/min) according to the following table.
*The initial dose of 80 mg and subsequent doses should be administered at these intervals. See following paragraph for dosage escalations.
| Creatinine Clearance || Dosing* Interval |
| mL/min || (hours) |
|<10||Dose should be individualized|
Since the terminal elimination half-life of sotalol is increased in patients with renal impairment, a longer duration of dosing is required to reach steady-state. Dose escalations in renal impairment should be done after administration of at least 5-6 doses at appropriate intervals (see table above).
Extreme caution should be exercised in the use of sotalol in patients with renal failure undergoing hemodialysis. The half-life of sotalol is prolonged (up to 69 hours) in anuric patients. Sotalol, however, can be partly removed by dialysis with subsequent partial rebound in concentrations when dialysis is completed. Both safety (heart rate, QT interval) and efficacy (arrhythmia control) must be closely monitored.
Pediatrics: The use of sotalol in pediatric patients with renal impairment has not been investigated. Sotalol elimination is predominantly via the kidney in the unchanged form. Use of sotalol in any age group with decreased renal function should be at lower doses or at increased intervals between doses. Monitoring of heart rate and QTc is more important and it will take much longer to reach steady-state with any dose and/or frequency of administration.
Transfer to SORINE®
Before starting Sorine® (Sotalol HCl) Tablets, previous antiarrhythmic therapy should generally be withdrawn under careful monitoring for a minimum of 2-3 plasma half-lives if the patient's clinical condition permits (see PRECAUTIONS, Drug Interactions). Treatment has been initiated in some patients receiving I.V. lidocaine without ill effect. After discontinuation of amiodarone, Sorine® should not be initiated until the QT interval is normalized (see WARNINGS).
Preparation of Extemporaneous Oral Solution
Information relating to the preparation of an extemporaneous oral solution of sotalol is approved for Berlex Laboratories' sotalol hydrochloride tablets. However, due to Berlex's marketing exclusivity rights, this drug product is not labeled with that information.
Transfer to BETAPACE AF™ from Sorine®
Patients with a history of symptomatic AFIB/AFL who are currently receiving sotalol for the maintenance of normal sinus rhythm should be transferred to BETAPACE AF™ because of the significant differences in labeling (i.e., patient package insert for BETAPACE AF™, dosing administration, and safety information).