Thread by @xhschan

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I am an infection doctor & scientist. My PhD is on unwanted effects of #antimalarial medicines, like chloroquine, on the heart. In overdose (taken too often or in excessive amounts) or in unapproved combinations, chloroquine, hydroxychloroquine & azithromycin kill #COVID19

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Important to use drugs at the right doses at which they have been properly evaluated, and as recommended by international guidelines from expert physicians and pharmacologists like @WHO. Antimalarials are typically dosed by body weight in kg.

who.int/docs/default-s…

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From global evidence review @WHO #malaria #drugsafety, co-chairs Prof Josep Brugada @hospitalclinic & Prof Sir Nick White @TropMedOxford, rapporteur @xhschan:

Chloroquine & hydroxychloroquine associated with sudden death in overdose @UMCGlobalSafety

who.int/malaria/mpac/m…

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From systematic review @dr_haeusler @WWARN @xhschan @MORUBKK:

"the lethality of chloroquine in overdose ha[s]...caused considerable concern over [its] use in the treatment of malaria"

Safe at malaria doses, but higher doses unclear as untested.

bmcmedicine.biomedcentral.com/articles/10.11…

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From systematic review & meta-analysis @xhschan @yan2016npt @dr_haeusler @slphyx @djimdeab @siqueira__andre @ricprice99 in @PLOSMedicine:

To complicate things, fever (at least from malaria) adds to effect on heart rhythm of antimalarials

journals.plos.org/plosmedicine/a…

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tl;dr

In these pandemic times, please use medicines only as approved by regulatory agencies like @US_FDA and as recommended by a medical practitioner. Getting it wrong will not only not cure #COVID19 but could kill you. Stay safe, everyone!