Why does quinidine cause paradoxical tachycardia?

By slowing the rate of atrial flutter/fibrillation, quinidine can decrease the degree of atrioventricular block and cause an increase, sometimes marked, in the rate at which supraventricular impulses are successfully conducted by the atrioventricular node, with a resultant paradoxical increase in ventricular rate (see …

Does quinidine cause arrhythmia?

Quinine, like quinidine, is a chincona alkaloid that has anti-arrhythmic property, although it also pro-arrhythmic that can cause various arrhythmias, including severe arrhythmia such as multiple PVC.

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.

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 are the side effects of the quinidine pill?

Gastrointestinal side effects have been the most frequently reported adverse effects. Anorexia, nausea, vomiting, and diarrhea occurred in up to 30% of patients. Quinidine pill esophagitis has been reported.

Can a person with ventricular tachycardia take quinidine?

Although quinidine therapy is usually considered contraindicated in patients with organic heart disease who develop ventricular arrhythmias, this therapy may be life-saving for patients with coronary disease developing arrhythmic storms attributable to polymorphic ventricular tachycardia.

Is it safe to take quinidine and other medications at the same time?

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective. Many drugs can affect quinidine. This includes prescription and over-the-counter medicines, vitamins, and herbal products.

How does quinidine affect the way the heart beats?

Quinidine affects the way that the heart beats. Quinidine is used to help keep the heart beating normally in people with certain heart rhythm disorders. Quinidine may also be used for purposes not listed in this medication guide.