डिगॉक्सिन और क्विनिडिन का इंटरैक्शन

Proarrhythmic effects Like many other drugs (including all other Class Ia antiarrhythmics), quinidine prolongs the QT c interval, and this can lead to torsades de pointes , a life-threatening ventricular arrhythmia (see OVERDOSAGE ).

Altered pharmacokinetics of other drugs: Quinidine slows the elimination of digoxin and simultaneously reduces digoxin's apparent volume of distribution.

When quinidine and digoxin are coadministered, digoxin doses usually need to be reduced.

This hazard may be decreased if partial atrioventricular block is achieved prior to initiation of quinidine therapy, using conduction-reducing drugs such as digitalis, verapamil, diltiazem, or a β-receptor blocking agent.

PRECAUTIONS Heart block In patients without implanted pacemakers who are at high risk of complete atrioventricular block (e.g., those with digitalis intoxication, second degree atrioventricular block, or severe intraventricular conduction defects), quinidine should be used only with caution.