Cessation of quinidine in these cases usually results in the disappearance of toxicity. Hypersensitivity to quinidine, although rare, should be constantly considered, especially during the first week of therapy. Weigh the benefits of such use in each patient against the possible hazards. Quinine, the levostereoisomer of quinidine, has caused fetal blindness and has been implicated in congenital deafness. Quinidine should be used during pregnancy only when clearly indicated.
Adverse effects occur in as many as a third of cases.
Other symptoms observed include palpitations, convulsions, faintness and flushing, localized edema, vertigo, tremor, light-headedness, excitement, apprehension, coma and even death. Very rare cases of lupus erythematosus, carpal tunnel syndrome and arthritis. Large doses may cause cinchonism, ventricular tachycardia, severe hypotension, cardiac standstill and ventricular fibrillation. Serious hypersensitivity reactions are manifested by respiratory embarrassment or cardiovascular collapse. If ingestion is recent, perform gastric lavage or induce emesis.