Until more robust evidence is available, the routine use of ivermectin for either the prevention or treatment of Covid-19 is not justified. In addition, the use of unregulated products purporting to contain ivermectin is risky and unethical.

This, according to a memo from the Ministerial Advisory Committee (MAC) on Covid-19, sent to Health Minister Zweli Mkhize on 7 January.

The memo is signed by MAC co-chairs professors Salim Abdool Karim and Marian Jacobs.

Ivermectin, a parasiticide, has been getting attention as a possible Covid-19 treatment, Health24 reported.

The drug works by paralysing and killing parasites in animals, notes the South African Health Products Regulatory Authority (Sahpra).

In South Africa, ivermectin is registered for use in animals, allowing veterinarians and other trained personnel to prescribe it as an antiparasitic agent for a variety of animals.

However, it is not currently registered for human use, although Sahpra stated it had occasionally granted permits for its use as treatment for individuals with conditions such as scabies or head lice.

According to the MAC's memo, the use of ivermectin for the treatment or prevention of Covid-19 has generated significant global interest.

"The use of this repurposed medicine is being heavily promoted via social media. However, given the limited evidence of efficacy and safety, as well as appropriate dosing of ivermectin, its place in therapy and prophylaxis remains uncertain at this point," the memo states.

"...motivated by concern for their patients, clinicians are grasping at any option which promises positive results. Ivermectin is being portrayed, despite the lack of high-quality evidence, as one such option. It has therefore been observed that unregulated use of ivermectin is evident in South Africa and increasing."

The MAC warned that no ivermectin-containing medicine for human use is registered in South Africa, and that there had been no applications for clinical trials involving ivermectin, nor for the registration of any ivermectin-containing medicine for the treatment or prevention of Covid-19.

"Using medicines not approved by Sahpra is illegal," it stated.

At least one political party, the National Freedom Party (NFP), as well as a collective of scientists and activists who call themselves the Ivermectin Interest Group, have called for the drug to be made available, City Press reported.

The NFP has gone as far as threatening to take Mkhize to court to demand an urgent meeting with him for the country to begin testing it and using it.

Ivermectin has been gaining traction as a "wonder drug", as some medical experts reportedly have suggested that the drug inhibits viral loads and keeps those with early symptoms of the disease from progressing to the hyper-inflammatory phase.

But while there are numerous anecdotal reports from general practitioners and pharmacists of the widespread prescribing and sale of ivermectin for these purposes, "no meaningful clinical data can be collected from this type of unregulated, off-label use," the MAC said.

"The vast majority of patients with Covid-19 will recover without specific pharmacological treatment."

The MAC said there is "some in vitro evidence" that ivermectin has antiviral activity against SARS-CoV-2, the virus that causes Covid-19.

"Other host-directed effects may also be possible. Ivermectin has been used, at various doses and in combination with other medicines, in a number of clinical studies, both observational and randomised."

But, it said, the currently available data have been reviewed by the National Essential Medicines Committee Covid-19 Subcommittee and Sahpra and are considered "insufficient to justify safe use in clinical practice at this point".

According to the memo, the Access to Covid-19 Tools (ACT) Accelerator has also commissioned a systematic review and meta-analysis of the available clinical trials evidence, but that process has yet to be concluded.

"More data are required from adequately powered, well-designed randomised clinical trials to demonstrate the efficacy and safety of ivermectin in both treatment and prevention of Covid-19. Some larger trials are ongoing, and it is hoped that the results will become available within the first quarter of 2021," the MAC said.

"There have been reports of apparent toxicity from overdoses of ivermectin. Although portrayed as safe, ivermectin is associated with a range of adverse effects when used in its registered indications in humans."

The MAC added that it was concerned about reports of profiteering from the sale of unlicensed products which purport to contain ivermectin.

"Prices as high as R500 per tablet have been reported. There is also anecdotal evidence that ivermectin is distributed for free in KwaZulu-Natal. Sahpra is investigating complaints of unregulated sale and use of ivermectin products."

Having reviewed the data, the MAC found that "there is insufficient evidence at this stage to support the routine use of ivermectin for either the prevention or treatment of Covid-19".

"The overall quality of randomised controlled clinical trials of ivermectin in the treatment of Covid-19 patient is poor and the existing trials are underpowered and poorly designed," it noted. A final report of a systematic review and meta-analysis is expected to be released in this week.

Sahpra has indicated that it would welcome and fast-track an application for a randomised controlled trial.

The MAC said the rapid review of the available evidence conducted by the National Essential Medicines List Committee (NEMLC) Covid-19 subcommittee suggested that ivermectin not be used for the treatment of patients with Covid-19, as the evidence of efficacy and safety is uncertain at this point.

The NEMLC is actively reviewing all available evidence and will continue to review emerging evidence from clinical trials that are ongoing. As of December 2020, there were 37 trials registered on Clinicaltrials.gov, it added.

"Emerging evidence must be actively sought and carefully reviewed. Reports of clinical trials of ivermectin for the prevention or treatment of Covid-19 must be closely watched, as they become available. As always, reports in peer-reviewed publications will be preferred," the MAC said.

However, at present, "unregulated distribution channels are at risk of the introduction of sub-standard and falsified products, which can be deleterious to human health", it said.