Quinidine and Sotalol interaction
Quinidine and Sotalol: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Quinidine (Quinidine Gluconate) label · effective 2024-08-27
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 ).
The effects (if any) of coadministration of other β-blockers on quinidine pharmacokinetics have not been adequately studied.
Coadministration of propranolol usually does not affect quinidine pharmacokinetics, but in some studies the β-blocker appeared to cause increases in the peak serum levels of quinidine, decreases in quinidine's volume of distribution, and decreases in total quinidine clearance.
From the Sotalol (Sotalol hydrochloride) label · effective 2025-07-31
Class Ia antiarrhythmic drugs, such as disopyramide, quinidine, and procainamide, and other Class III drugs (for example, amiodarone) are not recommended as concomitant therapy, because of their potential for additive QTc prolongation [see Warnings and Precautions ( 5.1 )].
Additive to other QT-prolonging drugs ( 7.1 , 7.2 )
Antiarrhythmic and other QT Prolonging Drugs Withdraw other Class I or Class III antiarrhythmic agents prior to dosing with sotalol.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.