Understanding ivermectin for humans vs what’s available for animal use

• Ivermectin for animals comes in five forms.
• Animal ivermectin may, however, be harmful to humans.
• Overdosing on ivermectin can have serious consequences on the human brain and eyesight.

 Ivermectin is one of the drugs being looked at as a possible treatment for Covid-19.

The product is not approved for use in humans in the country, but has recently been cleared for compassionate-use access by the South African Health Products Regulatory Authority (Sahpra) for the treatment of Covid-19.

Because human-use ivermectin is not available in South Africa, it will need to be imported – for which special authorisation will be required.

The form of ivermectin currently approved for use and available in the country (legally), is not for human use.

This form of ivermectin has been approved for use in animals. Despite this, reports have emerged of people using the veterinary version, raising huge safety concerns.

Health24 spoke to veterinary experts about ivermectin.

Ivermectin in South Africa

Ivermectin is commonly used for internal and external parasites in animals, predominantly in livestock like sheep and cattle, according to the president of the South African Veterinary Association Dr Leon de Bruyn.

The drug is also used in companion animals like dogs. It is an over-the-counter drug for animals and Sahpra has recently made it a schedule three drug for humans in its compassionate-use programme.

Veterinary vs human use

According to De Bruyn, ivermectin for animals is available in five forms: injectable; oral liquid; powder; pour-on; and capsules, with the injectable form by far the most common.

Ivermectin for humans comes in pill or tablet form – and doctors need to apply to Sahpra for a Section 21 permit to dispense it to humans.

Is it safe for human consumption?

Although the inactive excipient or carrier ingredients present in ivermectin for animals are also found as additives in human drinks and food, De Bruyn stressed that the livestock products are not registered for human consumption.

“Ivermectin has been used for many years for humans [as a treatment for certain other diseases]. It is relatively safe. But we don’t know exactly that if we use it so regularly to treat or prevent the Covid-19 what the long-term effects are, but also it can have quite serious effects on the brain if overdosed (sic).

“You know, people can become blind or go into a coma. So, it’s very important that they consult a health professional, and that they follow the dosage instructions they receive from that health professional,” Dr De Bruyn said.

Professor Vinny Naidoo is the dean of the Faculty of Veterinary Science at the University of Pretoria and an expert in veterinary pharmacology.

In a piece he wrote, Naidoo stated that there was no evidence that veterinary ivermectin worked for humans.

He also warned that the clinical trials on humans involved only a small number of patients and, therefore, people who took ivermectin needed to be observed by doctors.

“While numerous clinical studies have indeed been undertaken on ivermectin and its effect on Covid-19, there have been concerns around some of the studies having had a small number of patients, that some of the doctors were not properly blinded [prevented from being exposed to information that might influence them], and that they had patients on a number of different drugs.

“This is why, when used, the patients need to be under the care of a doctor, to allow for proper patient monitoring,” Naidoo wrote.