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...

Ibutilide fumarate (Corvert - Pharmacia & Upjohn), a new antiarrhythmic drug for intravenous use, has been approved by the US Food and Drug Administration for acute termination of atrial fibrillation or flutter of recent onset.

Dronedarone (Multaq - Sanofi-Aventis) has been approved by the FDA for oral treatment of atrial fibrillation and flutter. Amiodarone (Cordarone, and others) is the most effective drug for this indication, but has considerable toxicity.

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.