What is the drug quinidine used for?
What is the drug quinidine used for?
Quinidine is used to treat certain types of irregular heartbeats. Quinidine is in a class of medications called antiarrhythmic medications. It works by making your heart more resistant to abnormal activity.
Is quinidine used for atrial fibrillation?
Background: Although quinidine has been used to terminate atrial fibrillation (AFib) for a long time, it has been recently classified to be used as a third-line-drug for cardioversion.
Is quinidine a cardiac depressant?
The main use of quinidine, however, involves its activity as a myocardial depressant—that is, it depresses the excitability and conduction velocity of nerve impulses and the contractility of the heart muscle. The drug also tends to lower blood pressure.
What is the mechanism of action of quinidine?
Mechanism of action Like all other class I antiarrhythmic agents, quinidine primarily works by blocking the fast inward sodium current (INa). Quinidine’s effect on INa is known as a ‘use dependent block’. This means at higher heart rates, the block increases, while at lower heart rates, the block decreases.
Does quinidine increase heart rate?
Quinidine significantly increased the heart rate at rest and at low levels of exercise. Quinidine had no significant effect on the systolic blood pressure response to any work load.
What is the indication for quinidine?
Chronic therapy with Quinidex (quinidine) is indicated for some patients at high risk of symptomatic atrial fibrillation/flutter; generally patients who have had previous episodes of atrial fibrillation/flutter that were so frequent and poorly tolerated as to outweigh, in the judgment of the physician and the patient.
What is quinidine arrhythmia?
Quinidine-Induced Arrhythmias The lack of correlation between plasma quin- idine concentrations and this adverse drug effect raises the possibility either that external factors (for example, hypokalemia) modulate the response to quinidine in vivo or that one or more unmeasured active metabolites play a role.
Does quinidine lower blood pressure?
Quinidine had no significant effect on the systolic blood pressure response to any work load. However, quinidine significantly decreased the systolic blood pressure at all exercising heart rates, compared to control, in 15 of the 17 subjects.
What conditions does quinidine treat?
This medication is used to treat or prevent many types of irregular heartbeats (heart arrhythmias such as atrial fibrillation). Quinidine can greatly improve your ability to perform normal activities by decreasing the number of irregular heartbeats you have.
Is quinidine the same as quinine?
Background. Quinidine is an optical isomer of quinine, originally extracted from the bark of the Cinchona tree and similar plant species.
Why was quinidine discontinued?
Quinidine is no longer widely used for the termination and prevention of arrhythmias because of concern about cardiac and systemic side-effects. This concern was not shared by the patient reported here, who took the drug continuously for 30 years.
How long does quinidine take to work?
Time to peak: Oral preparation is approximately 2 hours, and extended-release preparations have around 3 to 4 hours. Bioavailability – Sustained release quinidine gluconate has shown to have higher serum concentrations than sustained-release quinidine sulfate.
Why is quinidine used as an antiarrhythmic agent?
Quinidine is used as a class I antiarrhythmic agent , that is, to prevent ventricular arrhythmias . [1] It is also used to maintain sinus rhythm after cardioversion of atrial fibrillation and to treat short QT syndrome .
Is it safe to take quinidine for ventricular arrhythmia?
Quinidine is occasionally used as a class I antiarrhythmic agent to prevent ventricular arrhythmias, particularly in Brugada Syndrome, although its safety in this indication is uncertain.
What kind of effect does quinidine have on the heart?
Like all other class I antiarrhythmic agents, quinidine primarily works by blocking the fast inward sodium current (I Na). Quinidine’s effect on I Na is known as a ‘use dependent block’. This means at higher heart rates, the block increases, while at lower heart rates, the block decreases.
Which is a Class 1 antiarrhythmic in the heart?
Quinidine is a pharmaceutical agent that acts as a class I antiarrhythmic agent (Ia) in the heart. It is a stereoisomer of quinine, originally derived from the bark of the cinchona tree. The drug causes increased action potential duration, as well as a prolonged QT interval.
