The Ministry of Health and Family Welfare has revised its advisory on the use of hydroxychloroquine as a prophylactic against the coronavirus, ANI reported on Friday. The ministry’s decision came after the National Task Force, constituted by the Indian Council of Medical Research, reviewed and recommended the use of the drug for coronavirus patients.

The National Task Force recommended administration of HCQ to asymptomatic healthcare workers in Covid-19 hospitals as well as those working in non-Covid-19 facilities. It said the dose should also be taken by asymptomatic frontline workers and asymptomatic household contacts of coronavirus patients.

An ICMR advisory released on Friday said that the health body undertook investigation at three (unidentified) central government hospitals in Delhi, The Print reported. It said the results of the investigation indicate that “healthcare workers involved in Covid-19 care, those on HCQ prophylaxis were less likely to develop SARS-CoV-2 [Covid-19] infection, compared to those who were not on it”.

The advisory added that the National Institute of Virology in Pune has found that the administration of HCQ reduces viral load in patients. ICMR also analysed data collected previously, known as retrospective case-control analysis, and found “a significant” relationship between “the number of doses taken and frequency of occurrence of Covid-19 infection in symptomatic healthcare workers who were tested for SARS-CoV-2 infection”.

However, the medical body said the effectiveness of HCQ was reduced in healthcare workers “caring for a general population”.

In April, ICMR had said that some side effects, such as abdominal pain and nausea, have been observed in healthcare workers who were administered HCQ. In its Friday advisory, the council said the drug should be discontinued if it causes “rare” side-effects such as cardiomyopathy and heart-rate disorders. In certain cases, hydroxychloroquine can also cause blurred vision, the advisory said.

The number of coronavirus infections continued to surge in India on Friday. The virus has so far infected 118,447 people in India, and killed 3,583, according to the Ministry of Health and Family Welfare. India imposed a nationwide lockdown on March 25 to limit the spread of Covid-19. The lockdown, extended thrice, is scheduled to end on May 31.

HCQ can increase mortality rate in hospitals, says Lancet study

But a study published in medical journal The Lancet on Friday said that hydroxychloroquine could in fact increase patient mortality rate in hospitals. The study also found that those administered the drug showed a higher frequency of arrhythmia, or irregular heartbeat.

The paper, co-authored by Mandeep R Mehra, Sapan S Desai, Frank Ruschitzka and Amit N Patel, analysed data of over 96,000 Covid-19 patients sourced from 671 hospitals across six continents over a span of nearly four months.

The study said that though chloroquine and hydroxychloroquine are shown to have antiviral properties in laboratory conditions, the use of this class of drugs for Covid-19 is based on a small number of anecdotal experiences that have shown variable responses in uncontrolled trials.

In April, India shipped large quantities of HCQ to over 100 countries including the United States, amid increasing clamour for the anti-malarial drug abroad. United States President Donald Trump has also strongly backed the drug, despite the Food and Drug Administration questioning its efficacy.

On May 19, Trump said he had been taking the drug for the past two weeks as he had “heard a lot of good stories”. “Hydroxychloroquine. I am taking it. Couple of weeks ago, started taking it,” Trump told media persons at the White House. “Heard a lot of good stories. And if its not good...I am not gonna get hurt by it. It’s been around for 40 years, for malaria, for lupus. Frontline workers take it, doctors take it.”

Follow today’s live updates on Covid-19 here