quinidine, Quinidine Gluconate, Quinidine Sulfate (cont.)

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There are three actions that are responsible for quinidine's ability to stop arrhythmias and prevent their recurrence. Quinidine decreases the speed of the electrical current that travels through the heart muscle that causes the heart muscle cells to contract. It also prolongs the period during which heart muscle cells can become electrically stimulated to contract and prolongs the recovery period after contraction during which the heart muscle cells cannot be stimulated to contract.

Quinidine blocks the normal effect of the vagus nerve on the heart, causing an increase in the rate at which the heart beats. Quinidine reduces the force of contraction of heart muscle cells, and therefore may impair the pumping efficiency of failing heart muscle as in congestive heart failure. Quinidine blocks alpha-receptors on the muscle cells that surround arteries which relaxes the muscle cells, lowers blood pressure ,and can cause excessively low blood pressure when combined with other drugs that also relax these muscle cells. Quinidine was approved by the FDA in July 1950.

PRESCRIBED FOR: Quinidine is an antiarrhythmic drug used in the treatment of abnormal heart rhythms, such as: atrial fibrillation, atrial flutter, and ventricular arrhythmias such as paroxysmal ventricular tachycardia. Quinidine also is used to treat malaria.

SIDE EFFECTS: The most common side effects are:

Medically Reviewed by a Doctor on 3/30/2015


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