London, A study that first claimed that anti-malaria drug hydroxychloroquine is an effective treatment for the novel coronavirus and triggered US President Donald Trump enthusiasm for its widespread use, has now been slammed by the same group that publishes the journal in which the paper first appeared.

The Scotland-based nonprofit International Society of Antimicrobial Chemotherapy (ISAC) has stressed that the study in question that appeared in its International Journal of Antimicrobial Agents (IJAA) "did not meet its standard".

The study was published as "Hydroxychloroquine and azithromycin as a treatment of COVID-19: results of an open-label non-randomized clinical trial" and was led by France-based University of Marseille's researcher Didier Raoult.

It reported testing 36 French COVID-19 patients in March, majority of them showing upper respiratory tract infection symptoms. They were given 600mg of hydroxychloroquine daily, and were tested every day via nasal swabs.

The addition of azithromycin to the treatment depended on patients' "clinical presentation."

According to a society statement, the "ISAC Board believes the article does not meet the Society's expected standard, especially relating to the lack of better explanations of the inclusion criteria and the triage of patients to ensure patient safety".

"Although ISAC recognises it is important to help the scientific community by publishing new data fast, this cannot be at the cost of reducing scientific scrutiny and best practices. Both Editors in Chief of our journals (IJAA and Journal of Global Antimicrobial Resistance) are in full agreement," said Andreas Voss, ISAC President.

Other scientists have also detailed serious problems with the study, including questions about its ethical underpinnings, messy confounding variables, missing patients, rushed and conflicted peer review and confusing data.

According to Retraction Watch, others have used PubPeer to report additional issues with the original Raoult article.

Hydroxychloroquine is a less toxic version of chloroquine, another malaria drug, which is related to quinine, an ingredient in tonic water.

President Trump called Prime Minister Narendra Modi, requesting him to supply the anti-malaria drug hydroxychloroquine that is being used to treat COVID-19 patients and as prophylactic by the frontline health care workers deployed in the fight against the coronavirus pandemic.

India imposed a ban on export of the drug since the coronavirus pandemic hit India.

The government has now decided to lift a partial ban on hydroxychloroquine, to export the drug to aid America's fight against the deadly COVID-19 disease.

The US has the highest number of the novel coronavirus cases in the world, with over 368,000 cases of infections and over 10,800 deaths.