Sotalol Hydrochloride

5 WARNINGS AND PRECAUTIONS QT prolongation, bradycardia, AV block, hypotension, worsening heart failure: Reduce dose or discontinue ( 5.1 ) Acute exacerbation of coronary artery disease upon cessation of therapy: Do not abruptly discontinue ( 5.5 ) Correct any electrolyte disturbances ( 5.1 ) Diabetes: May mask symptoms of hypoglycemia and alter glucose levels; monitor ( 5.7 ) 5.1 QT Prolongation and Proarrhythmia Sotalol hydrochloride can cause serious and potentially fatal ventricular arrhythmias such as sustained VT/VF, primarily Torsade de Pointes (TdP) type ventricular tachycardia, a polymorphic ventricular tachycardia associated with QT interval prolongation. Factors such as reduced creatinine clearance, female sex, higher doses, reduced heart rate, and history of sustained VT/VF or heart failure increase the risk of TdP. The risk of TdP can be reduced by adjustment of the sotalol dose according to creatinine clearance and by monitoring the ECG for excessive increases in the QT interval [see Dosage and Administration ( 2.1 )] . Correct hypokalemia or hypomagnesemia prior to initiating sotalol hydrochloride, as these conditions can exaggerate the degree of QT prolongation, and increase the potential for Torsade de Pointes. Special attention should be given to electrolyte and acid-base balance in patients experiencing severe or prolonged diarrhea or patients receiving concomitant diuretic drugs. Proarrhythmic events must be anticipated not only on initiating therapy, but with every upward dose adjustment [see Dosage and Administration ( 2.1 )] . Avoid use with other drugs known to cause QT prolongation [see Drug Interactions ( 7.1 )] . 5.2 Bradycardia/Heart Block/Sick Sinus Syndrome Sinus bradycardia (heart rate less than 50 bpm) occurred in 13% of patients receiving sotalol in clinical trials, and led to discontinuation in about 3% of patients. Bradycardia itself increases the risk of Torsade de Pointes. Sinus pause, sinus arrest and sinus node dysfunction occur in less than 1% of patients. The incidence of 2nd- or 3rd-degree AV block is approximately 1%. Sotalol hydrochloride is contraindicated in patients with sick sinus syndrome because it may cause sinus bradycardia, sinus pauses, or sinus arrest. 5.3 Hypotension Sotalol produces significant reductions in both systolic and diastolic blood pressures and may result in hypotension. Monitor hemodynamics in patients with marginal cardiac compensation. 5.4 Heart Failure New onset or worsening heart failure may occur during initiation or uptitration of sotalol because of its beta- blocking effects. Monitor for signs and symptoms of heart failure and discontinue treatment if symptoms occur. 5.5 Cardiac Ischemia after Abrupt Discontinuation Following abrupt cessation of therapy with beta-adrenergic blockers, exacerbations of angina pectoris and myocardial infarction may occur. When discontinuing chronically administered sotalol hydrochloride, particularly in patients with ischemic heart disease, gradually reduce the dosage over a period of 1 to 2 weeks, if possible, and monitor the patient. If angina markedly worsens or acute coronary ischemia develops, treat appropriately and consider use of an alternative beta-blocker. Warn patients not to interrupt therapy without their physician’s advice. Because coronary artery disease is common, but may be unrecognized, the abrupt discontinuation of sotalol may unmask latent coronary insufficiency. 5.6 Bronchospasm Patients with bronchospastic diseases (for example chronic bronchitis and emphysema) should not receive beta-blockers. If sotalol hydrochloride is to be administered, use the smallest effective dose to minimize inhibition of bronchodilation produced by endogenous or exogenous catecholamine stimulation of beta-2-receptors. 5.7 Effects on Blood Sugar Beta-blockers may prevent early warning signs of hypoglycemia, such as tachycardia, and increase the risk for severe or prolonged hypoglycemia at any time during treatment, especially in patients with diabetes mellitus or children and patients who are fasting (i.e., surgery, not eating regularly, or are vomiting). If severe hypoglycemia occurs, patients should be instructed to seek emergency treatment. Elevated blood glucose levels and increased insulin requirements can occur in diabetic patients. 5.8 Thyroid Abnormalities Avoid abrupt withdrawal of beta-blockade in patients with thyroid disease because it may lead to an exacerbation of symptoms of hyperthyroidism, including thyroid storm. Beta-blockade may mask certain clinical signs (for example, tachycardia) of hyperthyroidism. 5.9 Anaphylaxis While taking beta-blockers, patients with a history of anaphylactic reaction to a variety of allergens may have a more severe reaction on repeated challenge, either accidental, diagnostic, or therapeutic. Such patients may be unresponsive to the usual doses of epinephrine used to treat the allergic reaction. 5.10 Major Surgery Chronically administered beta-blocking therapy should not be routinely withdrawn prior to major surgery; however, the impaired ability of the heart to respond to reflex adrenergic stimuli may augment the risks of general anesthesia and surgical procedures.