What we know about chloroquine overdose comes from experience in France (suicide cases) and areas of malaria. 

Death can occur within 1 hour of toxic ingestion! 

Hydroxychloroquine was derived from chloroquine in 1946 – less toxic 

Used in malaria treatment and prophylaxis (blocks erythrocyte destruction)

Used in treatment of rheumatoid arthritis, lupus, etc (anti-inflammatory) 

Clinical symptoms: N/V/D, drowsy, AMS, seizure

HYPOTENSION, usually within 1 hour of toxic ingestion

Cardiotoxic:

Blocks Na channels – prolongs QRS

Blocks K channels – prolongs QTc, risk of Torsades 

Hypokalemia (from intracellular shifting) 

TREATMENT of hydroxychloroquine overdose extrapolated from treatment of chloroquine overdose – aggressive, early supportive care 

*Early intubation 

*Consider activated charcoal via NG tube (consider w/in 2 hours of ingestion) 

*Benzo of choice = Diazepam (high doses)

 2mg/kg over 30 minutes 

Some animal studies and case reports of co-ingestion of diazepam and chloroquine found benefit - better hemodynamic stability 

*Vasopressor of choice = Epinephrine

0.25mcg/kg/min titrated for SBP >90

*Permissive hypokalemia (~2.5 mmol/L)

Can lead to rebound hyperkalemia and dysrhythmias as poisoning resolves if potassium is overly corrected 

Note - Epi and Na bicarb can worse hypokalemia 

Need to Watch electrolytes closely! 

*Na Bicarb to counter Na blockade effects (if QRS >110 ms) 

*Intralipid emulsion therapy 

Case reports that show it may help – early treatment led to survival 

Creates a lipid sink to grab onto free circulating drugs and maybe pulls drug off receptors, also thought to improve cardiac contractility

Little down side – can interfere with some lab results and ECMO circuits 

Right now there is not great data on hydroxychloroquine/chloroquine in the treatment of COVID-19. 

The Cooper EM team plans to discuss the article on hydroxychloroquine and azithromycin in treatment of COVID-19 at our journal club today! Stay tuned!