Brand Names of Quinidine
Quinidine is available as quinidine sulfate and quinidine gluconate, with brand names including Quinidex, Quinora, Quiniday, and Quinaglute Dura-Tabs.
Available Formulations
Quinidine is available in two primary salt forms:
Quinidine Sulfate:
Quinidine Gluconate:
- Brand name:
- Quinaglute Dura-Tabs (648 mg twice daily) 2
- Brand name:
Clinical Context
Quinidine is classified as a Class IA antiarrhythmic drug according to the Vaughan Williams classification 3. It has been used for:
- Management of atrial fibrillation
- Treatment of ventricular arrhythmias
- Treatment of severe Plasmodium falciparum malaria (as quinidine gluconate) 3
Formulation Differences
The different formulations offer various dosing schedules:
- Immediate-release formulations (e.g., Quinora): Require more frequent dosing (four times daily)
- Extended-release formulations (e.g., Quinidex Extentabs): Allow twice-daily dosing
- Long-acting formulations (e.g., Quiniday): Allow once-daily dosing
Important Considerations
Quinidine is used less frequently than other antiarrhythmic agents due to:
- Perception of lower efficacy compared to newer agents 3
- Higher frequency of side effects, including QT-interval prolongation that may lead to torsades de pointes 3
- Risk of hypotension and acceleration of ventricular response to atrial fibrillation on a vagolytic basis during initiation of therapy 3
Despite these concerns, quinidine has seen renewed interest in specific clinical scenarios, including:
- Treatment of idiopathic ventricular fibrillation
- Management of Brugada syndrome
- Treatment of Short QT syndrome 4
When used for malaria treatment, quinidine gluconate is administered intravenously with careful cardiac monitoring due to potential cardiotoxicity 3.