Quinine showed medium antiviral
in vitro activity with EC50 of 10.7 ± 3.0 μM and EC90 of 38.8 ± 34 μM. A 600 mg single oral dose of quinine sulphate led to blood Cmax around 3.5 mg/l (around 8.5 μM) [
60]. In rat, after intravenous dose of 10 mg/kg of quinine, the observed concentration lung/blood ratio was 246 [
61]. The
in vitro effective concentration in lungs to cure SARS-CoV-2 is achievable in human. If its clinical efficacy in human would be confirmed, quinine could be administered in intravenous in patients before cytokine storm. Quinine can cause haemolytic anemia in patients with G6PD deficiency and severe side-effects including cardiac toxicity [
52]. Additionally, quinine could be associated with doxycycline against COVID-19, as is done in malaria treatment [
62].