(Reuters) – Healthcare professionals should closely monitor COVID-19 patients receiving malaria drug hydroxychloroquine for serious side effects, the European health regulator said on Friday, stressing the need for in-depth clinical data on benefits and risks.

Several EU countries this week halted the use of the drug, which has been championed by U.S. President Donald Trump as an effective treatment for COVID-19. (https://bit.ly/3cgboAO)

France, Italy and Belgium followed a World Health Organization decision on Monday to pause a large trial of the drug on COVID-19 patients.

Some observational studies that are less reliable, including one published in the medical journal the Lancet last week, have shown that the drug is tied to a higher risk of death and heart rhythm problem for coronavirus patients. But the medical community is waiting for outcomes from gold-standard scientific trials. (https://reut.rs/2TOfPfU)

“It is important that properly designed, randomised clinical trials can be completed, with adjustments as needed, to generate the necessary evidence on benefits and risks of these medicines in COVID-19,” the European Medicines Agency said. (https://bit.ly/3cgboAO)

Randomized trials involve comparing drugs with a placebo, with neither doctors nor patients aware of who gets what.

The EMA reiterated its stance that while further analyses are being carried out, chloroquine and hydroxychloroquine should only be used in clinical trials or in national emergency use programmes under close supervision for COVID-19 patients.

The decades-old drug is approved for treating rheumatoid arthritis and lupus.

(Reporting by Pushkala Aripaka and Ankur Banerjee in Bengaluru; Editing by Saumyadeb Chakrabarty)