Quinidine Sulfate Tablet has 25 known drug interactions based on U.S. FDA drug labeling data. 2 are classified as major interactions requiring close medical supervision. Notable interactions include combinations with Digoxin, Warfarin, Amiodarone. Patients taking Quinidine Sulfate Tablet should inform their healthcare provider of all current medications — including over-the-counter drugs and supplements — to avoid potentially harmful combinations. Data sourced from OpenFDA and the NIH National Library of Medicine.
- Total
- 25
- Major
- 2
- Moderate
- 12
- Minor
- 1
Major (2)
- Quinidine Sulfate Tablet + Digoxin— Quinidine slows elimination of digoxin and reduces its volume of distribution, potentially doubling serum digoxin levels…
- Quinidine Sulfate Tablet + Warfarin— Quinidine potentiates anticoagulatory action of warfarin; anticoagulant dosage may need reduction.
Moderate (12)
- Quinidine Sulfate Tablet + Amiodarone— Increases quinidine levels by pharmacokinetic mechanisms not well understood.
- Quinidine Sulfate Tablet + Andthiazide— Alkalinize urine and reduce renal elimination of quinidine, increasing quinidine levels.
- Quinidine Sulfate Tablet + Cimetidine— Increases quinidine levels by pharmacokinetic mechanisms not well understood.
- Quinidine Sulfate Tablet + Diltiazem— Significantly decreases quinidine clearance and increases quinidine half-life.
- Quinidine Sulfate Tablet + Ketoconazole— Quinidine levels rise due to competition for the P450 IIIA4 metabolic pathway.
- Quinidine Sulfate Tablet + Mao Inhibitors— Alkalinize urine and reduce renal elimination of quinidine, increasing quinidine levels.
- Quinidine Sulfate Tablet + Mexiletine— Quinidine inhibits P450 IID6-dependent metabolism, potentially increasing mexiletine levels.
- Quinidine Sulfate Tablet + Phenobarbital— Induces cytochrome P450 IIIA4, accelerating hepatic elimination and decreasing quinidine levels.
- Quinidine Sulfate Tablet + Phenytoin— Induces cytochrome P450 IIIA4, accelerating hepatic elimination and decreasing quinidine levels.
- Quinidine Sulfate Tablet + Rifampin— Induces cytochrome P450 IIIA4, accelerating hepatic elimination and decreasing quinidine levels.
- Quinidine Sulfate Tablet + Sodium Bicarbonate— Alkalinizes urine and reduces renal elimination of quinidine, increasing quinidine levels.
- Quinidine Sulfate Tablet + Verapamil— Significantly reduces hepatic clearance of quinidine with corresponding increases in serum levels and half-life.
Minor (1)
- Quinidine Sulfate Tablet + Nifedipine— Very rarely decreases quinidine levels by mechanisms not understood.