The World Health Organization on Tuesday recommended against the general use of 'ivermectin' - an orally-administered drug used to treat parasitic infections - for treatment of COVID-19 patients.
"Safety and efficacy are important when using any drug for a new indication. WHO recommends against use of 'ivermectin' for COVID-19 except within clinical trials," Dr Soumya Swaminathan, the global health body's chief scientist, tweeted.
A similar warning has also been issued by 'ivermectin' manufacturer MSD, or Merck & Co., Inc, whose statement Dr Swaminathan attached to her tweet. Merck said its scientists continue to "carefully examine findings of all available and emerging studies of 'ivermectin' for treatment of COVID-19".
"...to-date, our analysis has identified: No scientific basis for a potential therapeutic effect against COVID-19 from pre-clinical studies; No meaningful evidence for clinical activity or efficacy in patients with COVID-19 disease, and; A concerning lack of safety data in the majority of studies," it said.
This is the second WHO warning against 'ivermectin' in the past two months.
In March it said there is "very low certainty of evidence" of the drug's effect on mortality or hospital admission.
"We currently lack persuasive evidence of a mechanism of action for 'ivermectin' in COVID-19, and any observed clinical benefit would be unexplained," the WHO said then.
Dr Swaminathan's tweet today comes a day after Goa approved use of 'ivermectin' as preventive treatment for all adults against the SARS-CoV2 virus that causes the COVID-19 disease.
Goa Health Minister Vishwajit P Rane said the state's green-lighting of the drug was after expert panels from the United Kingdom, Italy, Spain and Japan found a "statistically significant reduction in mortality, time to recovery, and viral clearance in COVID-19 patients treated with 'ivermectin'".
Mr Rane said treatment - 12 mg for five days - would be available for everyone over 18.
Last month the Union Health Ministry, while issuing revised guidelines for home isolation of asymptomatic Covid cases, indicated use of 'ivermectin' to control fevers.
The WHO chief scientist's tweet today is important given growing debate over the efficacy of 'ivermectin', which is approved - in specific doses - for infections caused by some parasitic worms.
It is not, at this stage, viewed as an antiviral drug; which is something the United States' Food and Drug Administration has stressed, saying, "Ivermectin is not approved for COVID-19 treatment."
There are, however, some studies that suggest the opposite.
A review of available data - published in the May-June issue of the American Journal of Therapeutics - claims 'ivermectin' can help end the pandemic.
"We conducted the most comprehensive review of the available data on ivermectin," Pierre Kory, President and Chief Medical Officer of the Front Line COVID-19 Critical Care Alliance (FLCCC) - a group of medical and scientific experts that led the study - said.
The authors have claimed a large and statistically significant reduction in mortality, time to recovery, and viral clearance in COVID-19 patients treated with 'ivermectin'.
'Ivermectin' is one of a number of drugs, antiviral or otherwise, being studied for and offered as COVID-19 treatment options. Others include Remdesivir - which is in great demand in India - and anti-malaria drug hydroxychloroquine - large quantities of which were exported by India last year.
The WHO has still not approved hydroxychloroquine and, last month, the centre said remdesivir is not a life-saving drug and its "unnecessary or irrational" use on Covid patients is unethical.
Remdesivir is, however, routinely recommended for treatment in India.
Medication to treat or lessen the impact of COVID-19 continue to make headlines in India and around the world, as many countries battle devastating waves of the infection.
This morning India, the current epicentre of the pandemic, reported over 3.2 lakh new cases and 3,876 deaths in the past 24 hours. The number of active cases is now over 37.15 lakh.
With input from AFP, PTI
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