In the yet to be published study, researchers from the Shanghai Jiao Tong University in China, recruited 150 patients hospitalised with COVID-19 and assigned them to two groups.
One group of 75 patients were assigned to hydroxychloroquine (HCQ) plus routine care, and the remaining 75 people were assigned to standard care alone, the researchers noted.
Both groups were cared for at 16 government-designated treatment centres, they said.
The clinicians administered HCQ with a loading dose of 1,200 milligrammes daily for three days followed by a maintained dose of 800 milligrammes daily for the remaining days.
They said the administration of HCQ may have resulted in the alleviation of some clinical symptoms, but did not do any better than standard care in reducing levels of the virus in patients hospitalised with COVID-19.
While lab studies had earlier shown promising results for HCQ in this regard, the scientists said their current findings are contrary.
"The discrepancy of the results between our trial and in-vitro studieshighlighted the importance of pre-clinical in-vivo studies in which, the pharmacokinetic, pharmacodynamic, and toxicity profiles of the tested drug should be established," the researchers wrote in the study.
They added that earlier studies showing positive outcomes for treating COVID-19 patients with HCQ had several limitations and must be viewed with caution.
"Promising anti-viral results of HCQ from the recent trial should be interpreted with caution due to its limited sample size and lack of randomisation design," they said.
However, the scientists said, the current study did not find any adverse side effects of the drug among the patients, except for one who showed signs of blurred vision.
"As a well-tolerated, cheap, and widely available drug, future trials to determine the clinical benefits of HCQ in preventing disease progression is critically important considering the ongoing pandemic COVID-19," they concluded. VIS VISVIS