The Union Ministry of Health and Family Affairs has approved the use of Gilead Sciences' drug remdesivir and anti-malaria drug hydroxychloroquine for patients with mild COVID-19 symptoms. For those with a moderate stage of illness, tocilizumab and convalescent plasma can be used as an off-label application, the revised 'Clinical Management Protocols for COVID-19' guidelines suggest. The ministry has also said the use of azithromycin with HCQ in severe cases should be stopped.

Under the emergency use authorisation, remdesivir can be administered to patients with moderate disease (those on oxygen), though it should not administered to patients with severe renal impairment, pregnancy or lactating females and children. The drug, administered in the form of injection, should be given at a dose of 200 mg on day one followed by 100 mg daily for five days, says the guidelines.

The off-label use of convalescent plasma can be considered in patients with moderate disease, who are not improving (oxygen requirement is progressively increasing) despite the use of steroids.

Tocilizumab can be administered to patients with moderate illness and progressively increasing oxygen requirements and mechanically ventilated patients not improving despite the use of steroids, the ministry guidelines suggest. Its dose is variable, ranging from 4 to 13 ml/kg -- usually, 200 ml single dose given slowly over not less than two hours, the document suggests.

The therapy involves taking antibodies from the blood of a person who has recovered from COVID-19 and transfusing those into a coronavirus patient to help kickstart the immune system to fight the infection.

As per the health ministry, hydroxychloroquine has demonstrated in vitro activity against COVID-19 and was shown to be clinically beneficial in several small single centre studies. "Nonetheless, several large observational studies with severe methodologic limitations have shown no effect on mortality or other clinically meaningful outcomes," it said.

As is the case with other anti-virals, this drug should be used as early in the disease course as possible to achieve any meaningful effects and should be avoided in patients with severe disease, the document suggests.

The ministry said the use of remdesivir, tocilizumab and convalescent plasma therapy, at present, is based on limited available evidence.  Further, use of these drugs is subject to limited availability in the country as of now, the document stated.

India currently does not manufacture remdesivir and Hetero, Jubilant Life Sciences, Cipla and Mylan NV have signed pacts with Gilead Sciences to manufacture and sale of remdesivir in India.

Gilead has also signed agreements with four more pharma companies, Dr Reddy's Laboratories Ltd, Biocon arm Syngene International Ltd, Zydu Cadila Ltd and Egypt-based Eva Pharma Pvt Ltd, for manufacturing and sale of remdesivir, which has shown greater impact during initial two phases of trials.