Hydrochloroquine not effective against COVID-19: Study

Hydrochloroquine, the anti-malaria drug which US President Donald Trump called a "game changer" against COVID-19, is not effective against the disease, according to a study which raises concerns about the drug's widespread usage by many governments across the world in fighting the pandemic.

The yet to be peer-reviewed study, published in the preprint server medRxiv, made a retrospective analysis of patients hospitalised with COVID-19 in all the Veterans Health Administration medical centers across the US.

The scientists, including those from the University of South Carolina in the US, analysed the associations between the use of drugs hydroxychloroquine, azithromycin, and corresponding clinical outcomes.

According to the researchers, hydroxychloroquine, alone or in combination with azithromycin, is being widely used in COVID-19 therapy based on anecdotal evidence.

In the study, the scientists assessed data on patients hospitalised with confirmed infection with the novel coronavirus, SARS-CoV-2, in all United States Veterans Health Administration medical centers until April 11.

They categorised 368 patients based on their exposure to hydroxychloroquine alone, or with azithromycin, in addition to standard supportive management for COVID-19.

The two primary outcomes noted in the study were death, and the need for mechanical ventilation.

Based on the findings, the scientists said there is no evidence that use of hydroxychloroquine reduced the risk of mechanical ventilation in patients hospitalized with COVID-19.

The scientists said they took into account the variation in the baseline characteristics of the patients across the three groups.

"Hydroxychloroquine use with or without co-administration of azithromycin did not improve mortality or reduce the need for mechanical ventilation in hospitalized patients," the scientists wrote in the study.

On the contrary, they said, hydroxychloroquine use alone was associated with an increased risk of death compared to standard care alone.

"Although ongoing randomized, controlled studies are expected to provide more informative evidence about hydroxychloroquine in the coming months, the outcomes observed in our study represent the best available data," the researchers wrote in the study.

Some limitations of the research, mentioned by the scientists, include the possibility of selection bias of study participants.

They said the study comprised only men whose median age was over 65 years, adding that the results may not necessarily reflect outcomes in women or in younger hospitalized populations.

"The findings from this retrospective study suggest caution in using hydroxychloroquine in hospitalized Covid-19 patients, particularly when not combined with azithromycin," the researchers concluded.