The FDA has required the manufacturer of the secondgeneration antipsychotic quetiapine (Seroquel) to add a warning to the labeling saying that use of the drug should be avoided in combination with other drugs that prolong the electrocardiographic QTc interval (Table 1). The warning is based only on postmarketing reports of QT-interval prolongation in patients who overdosed on the drug, had concomitant illness, or were taking other drugs known to cause electrolyte imbalances or increase the QT interval. QT prolongation can lead to torsades de pointes, a potentially fatal cardiac...

Propafenone (Rythmol - Knoll), a class IC antiarrhythmic drug used in Europe for treatment of various arrhythmias for more than 10 years, was recently marketed in the USA for oral treatment of life-threatening ventricular arrhythmias such as sustained ventricular tachycardia. This restrictive labeling reflects concerns arising from the interim report of the Cardiac Arrhythmia Suppression Trial, in which post-myocardial infarction patients with asymptomatic or mildly symptomatic ventricular arrhythmias treated with the class IC antiarrhythmic drugs encainide (Enkaid) or flecainide...

Flecainide (Tambocor -3M Pharmaceuticals), first introduced in 1985 for treatment of ventricular arrhythmias, was recently approved by the US Food and Drug Administration for oral use to prevent supraventricular arrhythmias. The indications for using flecainide to treat ventricular arrhythmias were limited after a controlled trial found that post-myocardial infarction patients with asymptomatic ventricular arrhythmias who took the drug had twice as high a mortality rate as patients who took placebo (DS Echt et al, N Engl Med, 324:781, 1991).

Moricizine (mor i'; siz een) hydrochloride (Ethmozine - Du Pont), a class I antiarrhythmic drug developed in the USSR, was recently approved by the US Food and Drug Administration (FDA) for oral treatment of life-threatening ventricular arrhythmias.

Sotalol (hydrochloride (Betapace -Berlex; Sotacor -Bristol Laboratories of Canada), an antiarrhythmic drug that prolongs repolarization (Class III) and also has beta-adrenergic-blocking activity (Class II), was recently approved by the US Food and Drug Administration (FDA) for oral treatment of life-threatening ventricular arrhythmias.

The drugs of choice for treatment of common cardiac arrhythmias are listed in Tables 1 and 2. Some drugs are recommended for indications that have not been approved by the FDA.

Recently pharmaceutical manufacturers have marketed a stereoisomer of a successful drug nearing patent expiration as a new drug. Examples, such as esomeprazole (Nexium) , levalbuterol (Xopenex), escitalopram (Lexapro) and dexmethylphenidate

The FDA has approved mavacamten (Camzyos – MyoKardia/BMS), a modulator of cardiac myosin, to improve functional capacity and symptoms in adults with New York Heart Association (NYHA) class II or III obstructive hypertrophic cardiomyopathy (HCM) who have a baseline left ventricular ejection fraction (LVEF) ≥55%. Mavacamten is the first drug in its class to become available in the US.

Therapeutics (AZCERT) has recently added the proton pump inhibitors (PPIs) omeprazole (Prilosec, and others), esomeprazole (Nexium, and others), lansoprazole (Prevacid, and others), and pantoprazole (Protonix, and generics) to its lists of Drugs with Conditional Risk of Torsades de Pointes (TdP) and Drugs to Avoid in Patients with Congenital Long QT Syndrome.1PPIs do not directly cause prolongation of the QT interval, but they can cause hypomagnesemia, which is often accompanied by hypocalcemia and hypokalemia and can result in cardiac repolarization disturbances such as QT interval...

Older patients are especially susceptible to drug-induced cognitive impairment. They are more likely to be taking multiple drugs, to have higher blood levels of those drugs because of renal or hepatic dysfunction, and to have pre-existing cognitive problems that make it difficult to detect the role of drugs causing new symptoms or making old ones worse.