Chloroquine poisoning in a child.

Chloroquine poisoning in children, although infrequent, is extremely dangerous because of the narrow margin between therapeutic and toxic doses. Children clinically present with apnea, seizures, and cardiac arrhythmias. We present the case of a 12-month-old infant, the second-youngest patient reported in the US literature to die from chloroquine poisoning. A serum level of 4.4 mg/L (13.64 mumol/L) was obtained after the infant ingested only one tablet (300 mg). This establishes a new minimal lethal dose/blood level for children. Although some pediatric and adult pharmacokinetic and clinical similarities exist, the outcome is different. Pediatric mortality is 80%, whereas adult mortality is only 10%. Pediatric ingestion cases are primarily unintentional, and most adult cases are suicide attempts. Current treatment in adults includes a protocol of diazepam and epinephrine. Further studies involving children and these medications and other modalities are needed to improve survival.