quinidine, Quinidine Gluconate, Quinidine Sulfate

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GENERIC NAME: quinidine

DISCONTINUED BRANDS: Quinidine Gluconate, Quinidine Sulfate

DRUG CLASS AND MECHANISM: Quinidine is an antiarrhythmic medication that is used to correct disturbances in the rhythm of the heart (antiarrhythmic). Other antiarrhythmic drugs within the same class include procainamide (for example, Pronestyl) and disopyramide (for example, Norpace). This class of antiarrhythmics is specifically called "Class I" antiarrhythmics, and they differ from other antiarrhythmic drugs because they work by interfering with the sodium channel in the membranes of cells. The sodium channel is part of the membrane (wall) surrounding every cell that allows sodium to pass through into the cell, making the cells (for example, muscle and nerve cells) excitable and, in the case of muscle cells, able to contract. Thus, the flow of sodium through these channels is necessary for the muscle cells of the heart to be stimulated to contract, and Class I antiarrhythmics decrease the electrical stimulation of the muscle cells.

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.

Medically Reviewed by a Doctor on 3/30/2015

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