(Yicai Global) May 15 -- An anti-malarial drug recommended for use with Covid-19 patients by US President Donald Trump and the US Food and Drug Administration has no significant effect on their treatment and has higher-than-standard side effects, according to a new paper published in the British Medical Journal.

Co-authored by a team of medical experts at Ruijin Hospital Affiliated to Shanghai Jiao Tong University, the paper was published in the BMJ yesterday. The team did clinical tests on 150 Covid-19 patients in 16 Chinese medical institutions from Feb. 11 to Feb. 29, treating half of them with hydroxychloroquine and the other half with standard treatments as the control group.

The result shows that the probability of negative conversion by 28 days in the standard of care plus hydroxychloroquine group was 85.4 percent, similar to that in the standard of care group (81.3 percent), while adverse events happened in 30 percent of hydroxychloroquine recipients, with non-recipients only recording 9 percent.

The negative results on the antiviral efficacy of hydroxychloroquine obtained in this trial are contradictory to the encouraging in vitro results and the recently reported promising results from a non-randomised trial in 36 patients, the report said.

Participants in the trial had mainly mild to moderate symptoms, with a median 16-day delay between symptom onset and hydroxychloroquine treatment, so the negative results of the trial are applicable only to patients with persistently mild to moderate Covid-19, and could not assess the antiviral efficacy of hydroxychloroquine at an earlier stage.

Trump has recommended hydroxychloroquine for Covid-19 treatment in public and on Twitter a number of times. The US FDA approved the use of hydroxychloroquine and chloroquine for treatment of Covid-19 at the end of March.

But there has been controversy about the efficacy and side effects of using hydroxychloroquine to treat Covid-19 sufferers. Larger clinical trials of hydroxychloroquine are still under way worldwide, including the launch last month of a third-phase clinical test on 440 patients by Swiss drugmaker Novartis.

Editors: Dou Shicong, Peter Thomas