Chloroquine and Hydroxychloroquine in the Treatment of Cardiac Arrhythmias

ONE of the drugs most commonly employed for the management of atrial fibrillation is quinidine. Its use was demonstrated as early as 1918 by Frey.1 The compound, a cinchona alkaloid and the d-diosteroisomer of quinine, although a most useful agent, has certain limitations, which have stimulated a search for drugs of similar therapeutic value but less toxic in character.Although quinine is known to have certain effects not unlike those of quinidine2 this action is much less intense.3 In 1939 a synthetic antimalarial agent, chloroquine, was introduced. Burn and Vane,4 in experimental studies, showed that this compound, a 4-amino quinoline, . . .