The latest clinical trial by Chinese researchers may disappoint doctors and patients worldwide hoping for the effectiveness of hydroxychloroquine, or HCQ, an anti-malaria and anti-inflammatory drug that has been used in several countries to treat COVID-19 cases.

The randomized controlled clinical trial conducted at 16 designated Chinese hospitals treating COVID-19 cases showed that the use of the drug did not accelerate the removal of the virus among mildly and moderately ill patients.

It was the world's first multicenter study of its kind to be released in a medical journal to assess the effectiveness of HCQ in treating novel coronavirus infection. A paper about the study was published on the website of the British Medical Journal on Friday.

"Compared with standard treatment, the use of HCQ for COVID-19 patients didn't help bring about a negative virus test result, nor did it shorten the term of the disease, and there exists a higher incidence rate of adverse drug reactions," said Xie Qing, director of the infectious disease department at Ruijin Hospital Affiliated with Shanghai Jiao Tong University School of Medicine, which led the multi-center research.

She said that the result of the trial did not support use of the drug, which was previously proven effective to inhibit the novel coronavirus through in vitro tests and was approved by several countries, including France and the United States, to treat COVID-19 patients.

Late last month, a study about a small sample clinical trial of HCQ on severe cases of COVID-19 published by Brazilian researchers on the Journal of the American Medical Association showed that the drug failed to reduce mortality and could cause heart problems.

In the Chinese study, 150 patients were randomized into two groups. Half of them were treated by the national treatment guideline and the other half were given an additional high-dose of HCQ－1,200 milligrams of the drug for the first three days and 800 mg for the remaining days.

The research results showed that the rate of the virus turning negative among the two groups showed little difference－85.4 percent and 81.3 percent respectively－after 28 days.

"Moreover, we found that the patients in the two groups didn't show a statistical difference in the median number of days when their clinical symptoms were alleviated," Xie said.

Researchers said the rate of adverse drug reactions among the group given HCQ was 30 percent, higher than the 9 percent of its counterpart group. The adverse reactions were mainly diarrhea and vomiting.

Qu Jieming, Party secretary of Ruijin Hospital, said that the participants were included in the study after a median of 16.6 days of showing symptoms, and the research provided insight for potential future studies to see the effectiveness of the drug if it is used earlier.

Tang Wei, a deputy chief physician from the respiration and critical care medicine department of the hospital, said that similar research was conducted at Shanghai Public Health Clinical Center, the designated hospital to treat COVID-19 cases in the city. Thirty patients were divided into two groups to be given standard treatment versus standard treatment plus HCQ.

"Their research, which obtained similar results as ours, excluded interference factors, such as the more than two weeks of disease development and drugs that have been used before their participation in the research," she said.