Quinidine is worth consideration in connection with the treatment of malaria. In some recorded cases of urticarial,1 asthmatic or anaphylactoid,2 or coryzal3 reaction to quinine, quinidine has been found to produce no such annoying side effect. While such patients are not numerous, every one of them presents a troublesome problem, and it is in the hope that quinidine may be found useful in some such cases that we call attention to this drug, a natural alkaloid of cinchona, the antimalarial value of which has been widely attested.
Quinidine, an optical isomer of quinine, was discovered in 1833 by Henry and Delondre. In 1834, "deceived by the analogies between quinidine and quinine," they decided that quinidine was merely a "hydrate of quinine."4 In 1847, Winckler discovered the alkaloid now known as cinchonidine and applied to it the name quinidine, which was free; thus began a confusion of