Ivermectin: we answer your burning questions

For TimesLive by Sanet Oberholzer

Dr Bettina Taylor (pictured above)

Last week a High Court order ruled that ivermectin, the contentious anti-parasitic drug that has harnessed much attention for its potential ability to suppress COVID-19 infections and its complications, may now be used in SA in the treatment of COVID-19. 

According to the ruling, the drug can now be prescribed and compounded, or mixed with other ingredients to create a drug suited to the needs of individual patients, and legally sold to patients. 

Previously, the South African Health Products Regulatory Authority (Sahpra) required doctors to apply through its Section 21 “compassionate use” programme to obtain permission to use ivermectin to treat patients. 

Last month, The World Health Organization issued a recommendation against using ivermectin to treat patients with COVID-19 except in instances in which clinical trials are being conducted, citing a lack of data demonstrating its benefits. 

A number of other health authorities, including the European Medicines Agency and the US Food and Drug Administration (FDA), have also recommend against using ivermectin to treat COVID-19. 

To better understand the debate around the use of the drug, we asked experts in the medical field to answer our most pressing questions.

What is ivermectin?

Ivermectin is an anti-parasitic drug that has been used to treat a variety of parasite infestations such as river blindness, head lice, scabies and intestinal strongyloidiasis in humans. 

According to Dr Kgosi Letlape, the President of the Health Professions Council of South Africa (HPSCA), as with all drugs you may accidentally find that a drug has some other effect that it was not developed for – if used for indications other than those approved by the regulator, its use is referred to as off-label.

In recent in-vitro tests that were conducted, ivermectin was shown to be an inhibitor of SARS-Cov-2, the virus that causes COVID-19. These findings have prompted some healthcare practitioners to petition for the off-label use of ivermectin in treating COVID-19. 

What is the animal / human connection?

As a drug, ivermectin is used in veterinary medicine for the treatment and control of parasitic infections such as heartworm and acariasis in animals. In SA, only ivermectin formulations for animal consumption were registered until recently.  This changed a few weeks ago when a topical ivermectin-containing preparation for the treatment of rosacea, a skin condition in humans was approved. 

Is it safe?

“It’s a registered drug, it’s a safe drug, it’s an approved drug for a particular purpose,” says Letlape. “If you know the dosage and you use it in that dosage, we know that it is safe. The question becomes about effectiveness in relation to Covid-19 and that is where the discussion has been.” 

That said, it is important to be cognisant of where you obtain ivermectin. According to advice given by EthiQal, a local insurer offering malpractice cover to healthcare practitioners, unless a product is obtained from an authorised source that complies with Sahpra standards, its quality and thus safety in humans is unknown.

Is it legal?

Because of the recent High Court ruling, patients can now legally access the drug if compounded by a practitioner licensed to do so on prescription by a healthcare provider registered to prescribe medication. 

“With regards to imported products, it is important to obtain these from sources authorised by Sahpra”, says Dr Bettina Taylor, the head of clinical risk management at EthiQal.  ““There are illegal products in the market that are by-passing standard regulatory processes aimed at preventing distribution of sub-standard medications.”   

What is the issue of contestation around using ivermectin to treat COVID-19 patients?

The authorisation of drugs doesn’t happen merely because it has been shown not to cause harm in patients – it also has to be shown to be effective before any healthcare authority can authorise it to treat a specific condition. 

“If a drug is designed for something and you want to use it for something else, you’ll have to provide the scientific evidence. All the World Health Organisation was saying is that we cannot endorse something that is not based on scientific evidence – it’s based on anecdotal evidence,” says Letlape.

According to Letlape, the kind of study to show the effectiveness of ivermectin in treating COVID-19 hasn’t been carried out in SA. “There has been anecdotal evidence and there have been reports from elsewhere. The problem is the compounding factor – it is very difficult to be able to say this is because of ivermectin because most patients are on heavy cocktails of medication.”

At this stage, numerous clinical trials are underway across the world in an attempt to provide this scientific evidence but nothing concrete has been found yet. 

Taylor says ivermectin should ideally only be administered in the context of a clinical trial so that we can understand if it can be beneficial and under what circumstances. 

“With ivermectin, we do not know the doses to be used to achieve benefits, if any, and whether at such doses more harm than good is done as a result of side-effects.  We also do not know how chronic use would impact this (which may be necessary if the drug is to be used for prevention),” she says.

Is it a feasible alternative to vaccinations?

Vaccines are given to prevent infection whereas ivermectin is being investigated predominantly to treat infections. “Contrary to vaccines, ivermectin has not been studied in large clinical trials to show that it is effective and safe in the context of Covid-19,”” says Taylor. “For all we know and contrary to available vaccines, ivermectin may offer no advantage”. 

Can I overdose on ivermectin?

Given limited information, Taylor says it would be difficult to define how much would have to be taken, for how long, to be deemed to be an overdose but concurs with Letlape’s very clear statement: you can overdose on anything. If a doctor has prescribed an ivermectin compound for you to administer at home, it is crucial to adhere to prescribed dosages.  

What’s in it?

“A recent study that analysed seven ivermectin formulations being sold in South Africa for human use, demonstrated that four of five formulations tested had at least one additional undeclared active pharmaceutical ingredient (API), while another product had seven,” says Taylor. These active ingredients ranged from non-steroidal anti-inflammatories to anti-depressants, and from anti-platelet to antiemetic drugs amongst others. 

“Other than not knowing the quantity of ivermectin in any product purchased illegally, there are safety concerns with regards to these unknown additional ingredients that can cause unexpected allergic reactions, drug interactions and side-effects specific to any undeclared ingredient.”

Unless you obtain a product containing ivermectin product through a legal source (either an unregistered product imported and distributed in line with the compassionate use programme, or a product compounded in line with a doctor’s prescription), you can’t be sure that you’re consuming a safe, regulated product.