Treatment of hydroxychloroquine overdose

Hydroxychloroquine overdoses are rarely reported with 7 previous cases foun d in the English medical literature. We report a case and review the litera ture. A 16-year-old girl ingested a handful of hydroxychloroquine 200mg, 30 minutes before presentation and presented with tachycardia (heart rate 110 beats/min), hypotension (systolic blood pressure 63 mm Hg), central nervou s system depression, conduction defects (QRS=0.14 msec), and hypokalemia (K =2.1 meq/L). She was treated with fluid boluses and dopamine, oxygen, and p otassium supplementation. Toxicologic tests confirmed the presence of hydro xychloroquine. The patient's hypotension resolved within 4.5 hours, serum p otassium stabilized in 24 hours, and tachycardia gradually decreased over 3 days. Although hydroxychloroquine overdoses are very rare, life-threatenin g hypotension, conduction problems, and hypokalemia can occur within 30 min utes of ingestion. Symptoms are similar to chloroquine and treatment must b e implemented quickly and should be modeled after experience with chloroqui ne overdoses. Treatment modalities need further study, but current recommen dations are: (1) diazepam for seizures and sedation; (2) early intubation a nd mechanical ventilation; (3) epinephrine for treatment of vasodilation an d myocardial depression; (4) potassium replacement with close monitoring of levels; (5) charcoal for gastrointestinal decontamination if ingestion occ urred within an hour; (6) high dose diazepam for life-threatening symptoms, until more information becomes available. No value was found for serum alk alinization or extracorporeal methods of drug removal. (Am J Emerg Med 2001 ;19: 420-424. Copyright (C) 2001 by W.B. Saunders Company).