Abstract
Background
We report a patient with a massive hydroxychloroquine overdose manifested by profound
hypokalemia and ventricular dysrhythmias and describe hydroxychloroquine toxicokinetics.
Case report
A 20-year-old woman (60 kg) presented 1 h after ingesting 36 g of hydroxychloroquine.
Vital signs were: BP, 66 mmHg/palpation; heart rate, 115/min; respirations 18/min;
oxygen saturation, 100% on room air. She was immediately given intravenous fluids
and intubated. Infusions of diazepam and epinephrine were started. Activated charcoal
was administered. Her initial serum potassium of 5.3 mEq/L decreased to 2.1 mEq/L
1 h later. The presenting electrocardiogram (ECG) showed sinus tachycardia at 119
beats/min with a QRS duration of 146 ms, and a QT interval of 400 ms (Bazett's QTc
563 ms). She had four episodes of ventricular tachydysrhythmias requiring cardioversion,
electrolyte repletion, and lidocaine infusion. Her blood hydroxychloroquine concentration
peaked at 28,000 ng/mL (therapeutic range 500–2000 ng/mL). Serial concentrations demonstrated
apparent first-order elimination with a half-life of 11.6 h. She was extubated on
hospital day three and had a full recovery.
Conclusion
We present a massive hydroxychloroquine overdose treated with early intubation, activated
charcoal, epinephrine, high dose diazepam, aggressive electrolyte repletion, and lidocaine.
The apparent 11.6 hour half-life of hydroxychloroquine was shorter than previously
described.
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Article Info
Publication History
Published online: August 06, 2019
Accepted:
August 5,
2019
Received:
June 19,
2019
Identification
Copyright
© 2019 Elsevier Inc. All rights reserved.
