By Professor Dr Moy Foong Ming

This is the second time I am writing on the advocacy of Ivermectin use for the prevention and treatment of COVID-19.

The proponents are now trying to influence the ADUNs and Members of Parliaments to pressurize the authority to approve the use of Ivermectin on COVID-19 patients.

I understand this is for the good will of the people as COVID-19 transmission is getting more widespread with the highest number of daily cases happened on the 15 July 2021, with 13,215 reported cases and accumulated deaths of 6,613.

However, in the process of advocating Ivermectin for the prevention and treatment of COVID-19, we should be evidence-based as we do not want to recommend a drug that may not be effective and may sidetrack the government's effort in the implementation of the National Vaccination Program.

Most of the evidence of Ivermectin use on the prevention and treatment of COVID-19 was based on small and poorly designed randomized controlled trials (RCTs). Therefore, systematic reviews with meta-analyses were carried out to pool all the small RCTs findings and to generate a pooled estimate with higher study power (increased sample size by adding up all samples from the small RCTs).

From the latest three systematic reviews (Romano 2021, Bryant 2021 and Hill 2021), Bryant 2021 and Hill 2021 produced positive results in all cause mortality.

The review by Bryant 2021 reported a Relative Risk (RR) of 0.38 (95% CI: 0.19, 0.73) and Hill 2021 reported an RR of 0.44 (95% CI: 0.25, 0.77).

These results mean that patients on Ivermectin could have mortality reduced by 62% (27% to 71%) and 56% (23% to 75%) by Bryant 2021 and Hill 2021 respectively.

These results looked very promising, but the included trials in the review were of low quality such as with small sample size, high heterogeneity in participants (i.e. close contacts of healthcare workers, mild, moderate and severe disease status), a high variety of treatment dosage and duration, different comparison groups (i.e. standard of care, placebo, addition of other drugs); many included trials were non-registered and non peer-reviewed.

In addition, one of the most promising trial (Elgazzar 2020) with the largest sample size of 600 participants giving positive results for Ivermectin used in the calculation of all-cause mortality was retracted from the preprint platform for unethical concerns.

When we re-ran the meta-analyses without this trial, the pooled results were nearer to the null (Bryant: 0.54; 95% CI: 0.31, 0.94; Hill : 0.58, 95%: 0.34, 0.97).

Based on this latest development, there seemed to be insufficient evidence to endorse Ivermectin to be use in the prevention or treatment of COVID-19.

Although patients have the right in the decision-making for treatment, the evidence of prescribing a drug needs to be sufficient and the clinicians need to be convinced of its effectiveness.

By influencing the members of parliament and ADUNS to pressurize the authority does not seem to be appropriate when a drug is involved. This is different from advocating a health policy on economic aspect etc.

Practice of medicine should be evidence-based, not by pressure from the public, politicians nor experts' opinions.

I welcome the use of Ivermectin in COVID-19 if and when there is sufficient evidence.

(Professor Dr Moy Foong Ming, Department of Social & Preventive Medicine, Faculty of Medicine, Universiti Malaya.)