Cinchonism: two case reports and review of acute quinine toxicity and treatment

Two cases of acute quinine toxicity are presented, one from self-poisoning and the other from an unidentified source. Both patients presented with acute bilateral blindness. They also experienced the classic symptoms of cinchonism, including nausea, vomiting, and tinnitus. Prolongation of the Q-T interval developed in both patients. Serum quinine levels of 5.3 mg/L and 13 mg/L were measured. Although their visual acuity improved, both patients had some residual deficit at follow-up. A review of the literature, including clinical presentation and emergency medicine diagnosis and management, is also presented.