BETAPACE AF^®
sotalol HCI

BETAPACE AF, (sotalol hydrochloride), is an antiarrhythmic drug with Class II (beta-adrenoreceptor blocking) and Class III (cardiac action potential duration prolongation) properties. It is supplied as a white, capsule-shaped tablet for oral administration. Sotalol hydrochloride is a white, crystalline solid with a molecular weight of 308.8. It is hydrophilic, soluble in water, propylene glycol and ethanol, but is only slightly soluble in chloroform. Chemically, sotalol hydrochloride is d,l-N-[4-[1-hydroxy-2-[(1-methylethyl)amino]ethyl]phenyl]methanesulfonamide monohydrochloride. The molecular formula is C₁₂H₂₀N₂O₃ S•HCl and is represented by the following structural formula:

BETAPACE AF tablets contain the following inactive ingredients: microcrystalline cellulose, lactose, starch, stearic acid, magnesium stearate, and colloidal silicon dioxide.

BETAPACE AF (sotalol hydrochloride) has both beta-adrenoreceptor blocking (Vaughan Williams Class II) and cardiac action potential duration prolongation (Vaughan Williams Class III) antiarrhythmic properties. BETAPACE AF (sotalol hydrochloride) is a racemic mixture of d- and l-sotalol. Both isomers 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.

In children, a Class III electrophysiological effect can be seen at daily doses of 210 mg/m² body surface area (BSA). A reduction of the resting heart rate due to the beta-blocking effect of sotalol is observed at daily doses ≥90 mg/m² in children.

Sotalol hydrochloride prolongs the plateau phase of the cardiac action potential in the isolated myocyte, as well as in isolated tissue preparations of ventricular or atrial muscle (Class III activity). In intact animals it slows heart rate, decreases AV nodal conduction and increases the refractory periods of atrial and ventricular muscle and conduction tissue.

In man, the Class II (beta-blockade) electrophysiological effects of BETAPACE AF are manifested by increased sinus cycle length (slowed heart rate), decreased AV nodal conduction and increased AV nodal refractoriness. The Class III electrophysiological effects in man include prolongation of the atrial and ventricular monophasic action potentials, and effective refractory period prolongation of atrial muscle, ventricular muscle, and atrio-ventricular accessory pathways (where present) in both the anterograde and retrograde directions. With oral doses of 160 to 640 mg/day, the surface ECG shows dose-related mean increases of 40-100 msec in QT and 10-40 msec in QT_c. In a study of patients with atrial fibrillation (AFIB)/flutter (AFIB/AFL) receiving three different oral doses of BETAPACE AF given q12h (or q24h in patients with a reduced creatinine clearance), mean increases in QT intervals measured from 12-lead ECGs of 25 msec, 40 msec and 54 msec were found in the 80 mg, 120 mg, and 160 mg dose groups, respectively. (See WARNINGS for description of relationship between QT_c and Torsade de Pointes type arrhythmias.) No significant alteration in QRS interval is observed.

In a small study (n=25) of patients with implanted defibrillators treated concurrently with sotalol, the average defibrillatory threshold was 6 joules (range 2-15 joules) compared to a mean of 16 joules for a non-randomized comparative group primarily receiving amiodarone.

In a dose-response trial comparing three dose levels of BETAPACE AF, 80 mg, 120 mg, and 160 mg with placebo given q12h (or q24h in patients with a reduced renal creatinine clearance) for the prevention of recurrence of symptomatic atrial fibrillation (AFIB)/flutter (AFL), the mean ventricular rate during recurrence of AFIB/AFL was 125, 107, 110 and 99 beats/min in the placebo, 80 mg, 120 mg and 160 mg dose groups, respectively (p<0.017 for each sotalol dose group versus placebo). In another placebo controlled trial in which BETAPACE AF was titrated to a dose between 160 and 320 mg/day in patients with chronic AFIB, the mean ventricular rate during recurrence of AFIB was 107 and 84 beats/min in the placebo and BETAPACE AF groups, respectively (p<0.001).

Twenty-five children in an unblinded, multicenter trial with supraventricular (SVT) and/or ventricular (VT) tachyarrhythmias, aged between 3 days and 12 years (mostly neonates and infants), received an ascending titration regimen with daily doses of 30, 90 and 210 mg/m² with dosing every 8 hours for a total of 9 doses. During steady-state, the respective average increases above baseline of the QT_c interval, in msec (%), were 2(+1%), 14(+4%) and 29(+7%) msec at the 3 dose levels. The respective mean maximum increases above baseline of the QT_c interval, in msec (%), were 23(+6%), 36(+9%) and 55(+14%) msec at the 3 dose levels. The steady-state percent increases in the RR interval were 3, 9 and 12%. The smallest children (BSA<0.33m²) showed a tendency for larger Class III effects (ΔQT_c) and an increased frequency of prolongations of the QT_c interval as compared with the larger children (BSA≥.0.33m²). The beta-blocking effects also tended to be greater in the smaller children (BSA<0.33m²). Both the Class III and beta-blocking effects of sotalol were linearly related with the plasma concentrations.

In a study of systemic hemodynamic function measured invasively in 12 patients with a mean LV ejection fraction of 37% and ventricular tachycardia (9 sustained and 3 non-sustained), a median dose of 160 mg twice daily of sotalol produced a 28% reduction in heart rate and a 24% decrease in cardiac index at 2 hours post dosing at steady-state. Concurrently, systemic vascular resistance and stroke volume showed non-significant increases of 25% and 8%, respectively. Pulmonary capillary wedge pressure increased significantly from 6.4 mmHg to 11.8 mmHg in the 11 patients who completed the study. One patient was discontinued because of worsening congestive heart failure. Mean arterial pressure, mean pulmonary artery pressure and stroke work index did not significantly change. Exercise and isoproterenol induced tachycardia are antagonized by sotalol, and total peripheral resistance increases by a small amount.

In hypertensive patients, sotalol produces significant reductions in both systolic and diastolic blood pressures. Although sotalol is usually well-tolerated hemodynamically, caution should be exercised in patients with marginal cardiac compensation as deterioration in cardiac performance may occur. (See WARNINGS: Congestive Heart Failure.)

In healthy subjects, the oral bioavailability of sotalol is 90-100%. After oral administration, peak plasma concentrations are reached in 2.5 to 4 hours, and steady-state plasma concentrations are attained within 2-3 days (i.e., after 5-6 doses when administered twice daily). Over the dosage range 160-640 mg/day sotalol displays dose proportionality with respect to plasma concentrations. Distribution occurs to a central (plasma) and to a peripheral compartment, with a mean elimination half-life of 12 hours. Dosing every 12 hours results in trough plasma concentrations which are approximately one-half of those at peak.

Sotalol does not bind to plasma proteins and is not metabolized. Sotalol shows very little intersubject variability in plasma levels. The pharmacokinetics of the d and l enantiomers of sotalol are essentially identical. Sotalol crosses the blood brain barrier poorly. Excretion is predominantly via the kidney in the unchanged form, and therefore lower doses are necessary in conditions of renal impairment (see DOSAGE AND ADMINISTRATION). Age per se does not significantly alter the pharmacokinetics of sotalol, but impaired renal function in geriatric patients can increase the terminal elimination half-life, resulting in increased drug accumulation. The absorption of sotalol was reduced by approximately 20% compared to fasting when it was administered with a standard meal. Since sotalol is not subject to first-pass metabolism, patients with hepatic impairment show no alteration in clearance of sotalol.

The combined analysis of two unblinded, multicenter trials (a single dose and a multiple dose study) with 59 children, aged between 3 days and 12 years, showed the pharmacokinetics of sotalol to be first order. A daily dose of 30 mg/m² of sotalol was administered in the single dose study and daily doses of 30, 90 and 210 mg/m² were administered q8h in the multi-dose study. After rapid absorption with peak levels occurring on average between 2-3 hours following administration, sotalol was eliminated with a mean half-life of 9.5 hours. Steady-state was reached after 1-2 days. The average peak to trough concentration ratio was 2. BSA was the most important covariate and more relevant than age for the pharmacokinetics of sotalol. The smallest children (BSA <0.33m²) exhibited a greater drug exposure (+59%) than the larger children who showed a uniform drug concentration profile. The intersubject variation for oral clearance was 22%.

BETAPACE AF is indicated for the maintenance of normal sinus rhythm [delay in time to recurrence of atrial fibrillation/atrial flutter (AFIB/AFL)] in patients with symptomatic AFIB/AFL who are currently in sinus rhythm. Because BETAPACE AF can cause life-threatening ventricular arrhythmias, it should be reserved for patients in whom AFIB/AFL is highly symptomatic. Patients with paroxysmal AFIB whose AFIB/AFL that is easily reversed (by Valsalva maneuver, for example) should usually not be given BETAPACE AF (see WARNINGS).

In general, antiarrhythmic therapy for AFIB/AFL aims to prolong the time in normal sinus rhythm. Recurrence is expected in some patients (see Clinical Studies).

Sotalol is also indicated for the treatment of documented life-threatening ventricular arrhythmias and is marketed under the brand name BETAPACE(sotalol hydrochloride). BETAPACE, however, must not be substituted for BETAPACE AF because of significant differences in labeling (i.e., patient package insert, dosing administration and safety information).

BETAPACE AF (sotalol hydrochloride) is contraindicated in patients with sinus bradycardia (<50 bpm during waking hours), sick sinus syndrome or second and third degree AV block (unless a functioning pacemaker is present), congenital or acquired long QT syndromes, baseline QT interval >450 msec, cardiogenic shock, uncontrolled heart failure, hypokalemia (<4 meq/L), creatinine clearance <40 mL/min, bronchial asthma and previous evidence of hypersensitivity to sotalol.

Ventricular Arrhythmia: BETAPACE AF (sotalol) can cause serious ventricular arrhythmias, primarily Torsade de Pointes (TdP) type ventricular tachycardia, a polymorphic ventricular tachycardia associated with QT interval prolongation. QT interval prolongation is directly related to the dose of BETAPACE AF. Factors such as reduced creatinine clearance, gender (female) and larger doses increase the risk of TdP. The risk of TdP can be reduced by adjustment of the BETAPACE AF dose according to creatinine clearance and by monitoring the ECG for excessive increases in the QT interval.

Treatment with BETAPACE AF must therefore be started only in patients observed for a minimum of three days on their maintenance dose in a facility that can provide electrocardiographic monitoring and in the presence of personnel trained in the management of serious ventricular arrhythmias. Calculation of the creatinine clearance must precede administration of the first dose of BETAPACE AF. For detailed instructions regarding dose selection, see DOSAGE AND ADMINISTRATION.

In eight controlled trials of patients with AFIB/AFL and other supraventricular arrhythmias (N=659) there were four cases of Torsade de Pointes reported (0.6%) during the controlled phase of treatment with BETAPACE AF. The incidence of Torsade de Pointes was significantly lower in those patients receiving total daily doses of 320 mg or less (0.3%), as summarized in Table 5 below. Both patients who had Torsade de Pointes in the group receiving >320 mg/day were receiving 640 mg/day. In the group receiving ≤320 mg daily, one case of TdP occurred at a daily dose of 320 mg on day 4 of treatment and one case occurred on a daily dose of 160 mg on day 1 of treatment.

Prolongation of the QT interval is dose related, increasing from baseline an average of 25, 40, and 50 msec in the 80, 120, and 160 mg groups, respectively, in the clinical dose-response study. In this clinical trial BETAPACE AF treatment was not initiated if the QT interval was greater than 450 msec and during therapy the dose was reduced or discontinued if the QT interval was ≥520 msec.

Experience in patients with ventricular arrhythmias is also pertinent to the risk of Torsade de Pointes in patients with AFIB/AFL (see below).

In patients with a history of sustained ventricular tachycardia, the incidence of Torsade de Pointes during sotalol treatment was 4% and worsened VT in about 1%; in patients with other less serious ventricular arrhythmias the incidence of Torsade de Pointes was 1% and new or worsened VT in about 0.7%. Additionally, in approximately 1% of patients, deaths were considered possibly drug related; such cases, although difficult to evaluate, may have been associated with proarrhythmic events. Torsade de Pointes arrhythmias in patients with VT/VF were dose related, as was the prolongation of QT (QT_c) interval, as shown in Table 6 below.

Table 7 below relates the incidence of Torsade de Pointes to on-therapy QT_c and change in QT_c from baseline. It should be noted, however, that the highest on therapy QT_c was in many cases the one obtained at the time of the Torsade de Pointes event, so that the table overstates the predictive value of a high QT_c.

In addition to dose and presence of sustained VT, other risk factors for Torsade de Pointes were gender (females had a higher incidence), excessive prolongation of the QT_c interval and history of cardiomegaly or congestive heart failure. Patients with sustained ventricular tachycardia and a history of congestive heart failure appear to have the highest risk for serious proarrhythmia (7%). Of the ventricular arrhythmia patients experiencing Torsade de Pointes, approximately two-thirds spontaneously reverted to their baseline rhythm. The others were either converted electrically (D/C cardioversion or overdrive pacing) or treated with other drugs (see Overdosage). It is not possible to determine whether some sudden deaths represented episodes of Torsade de Pointes, but in some instances sudden death did follow a documented episode of Torsade de Pointes. Although sotalol therapy was discontinued in most patients experiencing Torsade de Pointes, 17% were continued on a lower dose.

The use of BETAPACE AF in conjunction with other drugs that prolong the QT interval has not been studied and is not recommended. Such drugs include many antiarrhythmics, some phenothiazines, bepridil, tricyclic antidepressants, and certain oral macrolides. Class I or Class III antiarrhythmic agents should be withheld for at least three half-lives prior to dosing with BETAPACE AF. In clinical trials, BETAPACE AF was not administered to patients previously treated with oral amiodarone for >1 month in the previous three months. Class Ia antiarrhythmic drugs, such as disopyramide, quinidine and procainamide and other Class III drugs (e.g., amiodarone) are not recommended as concomitant therapy with BETAPACE AF because of their potential to prolong refractoriness (see WARNINGS). There is only limited experience with the concomitant use of Class Ib or Ic antiarrhythmics.

BETAPACE AF (sotalol hydrochloride) is eliminated principally via the kidneys through glomerular filtration and to a small degree by tubular secretion. There is a direct relationship between renal function, as measured by serum creatinine or creatinine clearance, and the elimination rate of BETAPACE AF. Guidance for dosing in conditions of renal impairment can be found under "DOSAGE AND ADMINISTRATION."

Please refer to the patient package insert.

Prior to initiation of BETAPACE AF® therapy, the patient should be advised to read the patient package insert and reread it each time therapy is renewed. The patient should be fully instructed on the need for compliance with the recommended dosing of BETAPACE AF®, the potential interactions with drugs that prolong the QT interval and other antiarrhythmics, and the need for periodic monitoring of QT and renal function to minimize the risk of serious abnormal rhythms.

 Sotalol is primarily eliminated by renal excretion; therefore, drugs that are metabolized by CYP450 are not expected to alter the pharmacokinetics of sotalol.

Proarrhythmic events were more common in sotalol treated patients also receiving digoxin; it is not clear whether this represents an interaction or is related to the presence of CHF, a known risk factor for proarrhythmia, in the patients receiving digoxin.

 BETAPACE AF should be administered with caution in conjunction with calcium blocking drugs because of possible additive effects on atrioventricular conduction or ventricular function. Additionally, concomitant use of these drugs may have additive effects on blood pressure, possibly leading to hypotension.

 Concomitant use of catecholamine-depleting drugs, such as reserpine and guanethidine, with a beta-blocker may produce an excessive reduction of resting sympathetic nervous tone. Patients treated with BETAPACE AF plus a catecholamine depletor should therefore be closely monitored for evidence of hypotension and/or marked bradycardia which may produce syncope.

Hyperglycemia may occur, and the dosage of insulin or antidiabetic drugs may require adjustment. Symptoms of hypoglycemia may be masked.

Beta-agonists such as salbutamol, terbutaline and isoprenaline may have to be administered in increased dosages when used concomitantly with BETAPACE AF.

 Beta-blocking drugs may potentiate the rebound hypertension sometimes observed after discontinuation of clonidine; therefore, caution is advised when discontinuing clonidine in patients receiving BETAPACE AF.

No pharmacokinetic interactions were observed with hydrochlorothiazide or warfarin.

Administration of BETAPACE AF within 2 hours of antacids containing aluminum oxide and magnesium hydroxide should be avoided because it may result in a reduction in Cmax and AUC of 26% and 20%, respectively and consequently in a 25% reduction in the bradycardic effect at rest. Administration of the antacid two hours after BETAPACE AF has no effect on the pharmacokinetics or pharmacodynamics of sotalol.

The presence of sotalol in the urine may result in falsely elevated levels of urinary metanephrine when measured by fluorimetric or photometric methods. In screening patients suspected of having a pheochromocytoma and being treated with sotalol, a specific method, such as a high performance liquid chromatographic assay with solid phase extraction (e.g., J. Chromatogr. 385:241, 1987) should be employed in determining levels of catecholamines.

No evidence of carcinogenic potential was observed in rats during a 24-month study at 137-275 mg/kg/ day (approximately 30 times the maximum recommended human oral dose (MRHD) as mg/kg or 5 times the MRHD as mg/m² ) or in mice, during a 24-month study at 4141-7122 mg/kg/day (approximately 450-750 times the MRHD as mg/kg or 36-63 times the MRHD as mg/m²).

Sotalol has not been evaluated in any specific assay of mutagenicity or clastogenicity.

No significant reduction in fertility occurred in rats at oral doses of 1000 mg/kg/ day (approximately 100 times the MRHD as mg/kg or 9 times the MRHD as mg/m²) prior to mating, except for a small reduction in the number of offspring per litter.

Adverse events that are clearly related to BETAPACE AF are those which are typical of its Class II (beta-blocking) and Class III (cardiac action potential duration prolongation) effects. The common documented beta-blocking adverse events (bradycardia, dyspnea, and fatigue) and Class III effects (QT interval prolongation) are dose related.

In a pooled clinical trial population consisting of four placebo-controlled studies with 275 patients with AFIB/AFL treated with 160-320 mg doses of BETAPACE AF, the following adverse events were reported at a rate of 2% or more in the 160-240 mg treated patients and greater than the rate in placebo patients (See Table 8). The data are presented by incidence of events in the BETAPACE AF and placebo groups by body system and daily dose. No significant irreversible non-cardiac end-organ toxicity was observed.

Overall, discontinuation because of unacceptable adverse events was necessary in 17% of the patients, and occurred in 10% of patients less than two weeks after starting treatment. The most common adverse events leading to discontinuation of BETAPACE AF were: fatigue 4.6%, bradycardia 2.4%, proarrhythmia 2.2%, dyspnea 2%, and QT interval prolongation 1.4%.

In clinical trials involving 1292 patients with sustained VT/VF, the common adverse events (occurring in ≥2% of patients) were similar to those described for the AFIB/AFL population.

Occasional reports of elevated serum liver enzymes have occurred with sotalol therapy but no cause and effect relationship has been established. One case of peripheral neuropathy which resolved on discontinuation of sotalol and recurred when the patient was rechallenged with the drug was reported in an early dose tolerance study. Elevated blood glucose levels and increased insulin requirements can occur in diabetic patients.

In an unblinded multicenter trial of 25 patients with SVT and/or VT receiving daily doses of 30, 90 and 210 mg/m² with dosing every 8 hours for a total of 9 doses, no Torsade de Pointes or other serious new arrhythmias were observed. One (1) patient, receiving 30 mg/m² daily, was discontinued because of increased frequency of sinus pauses/bradycardia. Additional cardiovascular AEs were seen at the 90 and 210 mg/m² daily dose levels. They included QT prolongations (2 patients), sinus pauses/bradycardia (1 patient), increased severity of atrial flutter and reported chest pain (1 patient). Values for QT_c ≥525 msec were seen in 2 patients at the 210 mg/m² daily dose level. Serious adverse events including death, Torsade de Pointes, other proarrhythmias, high-degree A-V blocks and bradycardia have been reported in infants and/or children.

Foreign marketing experience with sotalol hydrochloride shows an adverse experience profile similar to that described above from clinical trials. Voluntary reports since introduction also include rare reports of: emotional liability, slightly clouded sensorium, incoordination, vertigo, paralysis, thrombocytopenia, eosinophilia, leukopenia, photosensitivity reaction, fever, pulmonary edema, hyperlipidemia, myalgia, pruritis, alopecia.

The oculomucocutaneous syndrome associated with the beta-blocker practolol has not been associated with BETAPACE AF during investigational use and foreign marketing experience.

Intentional or accidental overdosage with sotalol has rarely resulted in death.

The most common signs to be expected are bradycardia, congestive heart failure, hypotension, bronchospasm and hypoglycemia. In cases of massive intentional overdosage (2-16 grams) of sotalol the following clinical findings were seen: hypotension, bradycardia, cardiac asystole, prolongation of QT interval, Torsade de Pointes, ventricular tachycardia, and premature ventricular complexes. If overdosage occurs, therapy with BETAPACE AF should be discontinued and the patient observed closely. Because of the lack of protein binding, hemodialysis is useful for reducing sotalol plasma concentrations. Patients should be carefully observed until QT intervals are normalized and the heart rate returns to levels >50 bpm. The occurrence of hypotension following an overdose may be associated with an initial slow drug elimination phase (half life of 30 hours) thought to be due to a temporary reduction of renal function caused by the hypotension. In addition, if required, the following therapeutic measures are suggested:

• Therapy with BETAPACE AF must be initiated (and, if necessary, titrated) in a setting that provides continuous electrocardiographic (ECG) monitoring and in the presence of personnel trained in the management of serious ventricular arrhythmias. Patients should continue to be monitored in this way for a minimum of 3 days on the maintenance dose. In addition, patients should not be discharged within 12 hours of electrical or pharmacological conversion to normal sinus rhythm.
• The QT interval is used to determine patient eligibility for BETAPACE AF treatment and for monitoring safety during treatment. The baseline QT interval must be ≤450 msec in order for a patient to be started on BETAPACE AF therapy. During initiation and titration, the QT interval should be monitored 2-4 hours after each dose. If the QT interval prolongs to 500 msec or greater, the dose must be reduced or the drug discontinued.
• The dose of BETAPACE AF must be individualized according to calculated creatinine clearance. In patients with a creatinine clearance >60 mL/min BETAPACE AF is administered twice daily (BID) while in those with a creatinine clearance between 40 and 60 mL/min, the dose is administered once daily (QD). In patients with a creatinine clearance less than 40 mL/min BETAPACE AF is contraindicated. The recommended initial dose of BETAPACE AF is 80 mg and is initiated as shown in the dosing algorithm described below. The 80 mg dose can be titrated upward to 120 mg during initial hospitalization or after discharge on 80 mg in the event of recurrence, by rehospitalization and repeating the same steps used during the initiation of therapy (see Upward Titration of Dose )
• Patients with atrial fibrillation should be anticoagulated according to usual medical practice. Hypokalemia should be corrected before initiation of BETAPACE AF therapy (see WARNINGS, Proarrhythmia in Ventricular Arrhythmia Patients: [see BETAPACE (sotalol hydrochloride) Package Insert]).
• Patients to be discharged on BETAPACE AF therapy from an in-patient setting should have an adequate supply of BETAPACE AF, to allow uninterrupted therapy until the patient can fill a BETAPACE AF prescription.

If the 80 mg dose level is tolerated and the QT interval remains <500 msec after at least 3 days (after 5 or 6 doses if patient receiving QD dosing), the patient can be discharged. Alternatively, during hospitalization, the dose can be increased to 120 mg bid and the patient followed for 3 days on this dose (followed for 5 or 6 doses if patient receiving QD doses).

The steps described above are summarized in the following diagram:

If the 80 mg dose level (given BID or QD depending upon the creatinine clearance) does not reduce the frequency of relapses of AFIB/AFL and is tolerated without excessive QT interval prolongation (i.e., ≥520 msec), the dose level may be increased to 120 mg (BID or QD depending upon the creatinine clearance). As proarrhythmic events can occur not only at initiation of therapy, but also with each upward dosage adjustment, Steps 2 through 5 used during initiation of BETAPACE AF therapy should be followed when increasing the dose level. In the U.S. multicenter dose-response study, the 120 mg dose (BID or QD) was found to be the most effective in prolonging the time to ECG documented symptomatic recurrence of AFIB/AFL. If the 120 mg dose does not reduce the frequency of early relapse of AFIB/AFL and is tolerated without excessive QT interval prolongation (≥520 msec), an increase to 160 mg (BID or QD depending upon the creatinine clearance), can be considered. Steps 2 through 5 used during the initiation of therapy should be used again to introduce such an increase.

Renal function and QT should be re-evaluated regularly if medically warranted. If QT is 520 msec or greater (JT 430 msec or greater if QRS is > 100 msec), the dose of BETAPACE AF therapy should be reduced and patients should be carefully monitored until QT returns to less than 520 msec. If the QT interval is ≥520 msec while on the lowest maintenance dose level (80 mg) the drug should be discontinued. If renal function deteriorates, reduce the daily dose in half by administering the drug once daily as described in Initiation of BETAPACE AF Therapy, Step 3.

The maximum recommended dose in patients with a calculated creatinine clearance greater than 60 mL/min is 160 mg BID, doses greater than 160 mg BID have been associated with an increased incidence of Torsade de Pointes and are not recommended. A patient who misses a dose should NOT double the next dose. The next dose should be taken at the usual time.

As in adults the following precautionary measures should be considered when initiating sotalol treatment in children: initiation of treatment in the hospital after appropriate clinical assessment; individualized regimen as appropriate; gradual increase of doses if required; careful assessment of therapeutic response and tolerability; and frequent monitoring of the QT_c interval and heart rate.

Before starting BETAPACE AF, 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 Drug interactions). Treatment has been initiated in some patients receiving I.V. lidocaine without ill effect. After discontinuation of amiodarone, BETAPACE AF should not be initiated until the QT interval is normalized (see WARNINGS).

BETAPACE AF (sotalol hydrochloride); capsule-shaped white scored tablets imprinted with the strength and "BERLEX" are available as follows:

Store at 25°C (77°F); excursions permitted to 15-30°C (59-86°F) [See USP Controlled Room Temperature].

What You Should Know About BETAPACE AF

(Bay' tah pace)

(generic name: sotalol hydrochloride)