Class IA dysrhythmic agent
Used to treat supraventricular & ventricular arrhythmias
Slows impulse conduction by blocking sodium channels
Decreases myocardial excitability, conduction velocity, and contractility
Prevents reentry phenomenon
Strongly anticholinergic effects (atropine-like) increases ventricular rate
Quinidine is the oldest and most thoroughly studied of all of the IA drugs.
It is the most frequently used oral antidysrhythmic.
Also has antipyretic and antimalarial properties.
Contraindicated in digitalis toxicity, heart blocks, hypersensitivity to quinidine (or cinchona derivatives)
Common adverse effects: GI symptoms, diarrhea (GI symptoms develop in 33% of patients) cinchonism - ringing in ears, HA, nausea, disturbed vision, vertigo. Can develop after one dose.
Serious adverse effect: Cardiotoxicity, arterial embolism, hypotension with IV use
Nursing: take oral forms with food, telemetry & vital sign monitoring/volumetric flow pump with IV administration. Be aware that quinidine can DOUBLE digoxin levels. Due to its anticholinergic action can intensify the effect of other anticholinergic agents resulting in excessive tachycardia.
Patient teaching: Instruct pt in signs of embolism