SIGAPORE, Sept 6 — Knowing that he is more susceptible to Covid-19 as he is unvaccinated, Tan went looking for his own preventative treatment and eventually learnt of the anti-parasite pharmaceutical ivermectin.

The drug is used to treat parasite infestations in humans such as head lice, but in larger quantities is also used to treat animals such as dogs and horses for conditions such as heartworm.

As the drug cannot be bought over the counter here and only via a prescription, the man in his 40s, who wanted to be known only by his last name, ordered a shipment of the drug from India.

His order of five boxes of 100 pills each arrived last month, and cost him US$65 (RM270). Since then he has been taking one dose a week as a "preventative” measure against Covid-19. In addition, he is also sharing the dose with four friends and family members.

Decisions by Tan and other Singaporeans to self-medicate with ivermectin reflects a trend in various countries worldwide with reports people are ignoring advisories from health authorities against using the drug.

For instance, ivermectin has reportedly jumped in price across Covid-ravaged Indonesia, where many people regard it as a "miracle cure”.

Among other agencies, the World Health Organization in March this year warned that ivermectin should be used to treat Covid-19 only in clinical trials and that evidence on its effectiveness against the coronavirus was "inconclusive”.

One manufacturer of the drug, Merck, has also reportedly stated that there is "no scientific basis” for ivermectin’s use treating Covid-19, and that its inappropriate use could lead to safety issues.

These warnings have not deterred users such as Tan who said that he had not been vaccinated as he does not trust the vaccine as it is a relatively new drug.

Another ivermectin user here, who did not wish to be named, had used Telegram chat to team up with other people to buy the drug in bulk.

He told TODAY "tens of people” had jumped on the order with him.

"As an unvaccinated person and a minority of us out there, it’s prudent for us to take precautionary measures,” he said.

Checks by TODAY identified at least three Telegram chats with people buying or consolidating orders for ivermectin.

Another prospective ivermectin user here, Ng Syn Jae, said that while the drug can be used for animals, there are doses and packaging of ivermectin that are meant for human consumption, and those are the ones he will be looking to consume should he be infected with Covid-19.

The 27-year-old, who is unvaccinated and preferred not to reveal his occupation, said that among the reasons why he trusts the drug is that it has been available for human use since 1981.

He added that because the drug is not seen as a Covid-19 treatment here, people who are uninformed may purchase the version of the drug meant for animals and thus experience harmful side effects.

Checks by TODAY at several pharmacies confirmed that ivermectin cannot be purchased over the counter, but only on prescription.

Tan said that the drug "looks legitimate”, though he did not bother to check through the details but trusted the credentials of the manufacturer and distributor.

Experts here agree with the WHO that there is no basis to believe that the drug is an effective treatment against the coronavirus, and that it could even be dangerous.

‘Dangerous to take medicines of unproven benefit’

Responding to queries from TODAY, Associate Professor Sophia Archuleta, who is the head of the Division of Infectious Diseases at the National University Hospital (NUH), said that the hospital does not use ivermectin as a Covid-19 treatment, and that it has not seen patients requesting the drug or being admitted with side effects associated with its use.

"It is dangerous to take medicines of unproven benefit for any medical condition especially as we currently have other proven effective treatments for Covid-19 (such as) remdesivir or dexamethasone,” said Assoc Prof Archuleta.

"Vaccination remains the most effective preventative method.”

In April this year, a team of clinician-scientists from the National University Health System (NUHS) released a study on Covid-19 preventative therapy done on more than 3,000 migrant workers during the height of the Covid-19 outbreak in dormitories in May last year.

While the study showed that oral hydroxychloroquine and povidone-iodine throat spray are somewhat effective in reducing the spread of Covid-19 in high transmission settings, ivermectin was less effective.

In June, the National Centre for Infectious Diseases (NCID) stated in its treatment guidelines for Covid-19 that the use of ivermectin as a Covid-19 treatment is "not recommended” as there is a "lack of robust data”.

TODAY has reached out to the Singapore authorities for comments on the use of ivermectin.

Surge in ivermectin use in some countries

According to the New York Times, prescriptions for ivermectin in the United States have risen sharply in recent weeks, jumping to more than 88,000 per week in mid-August from a pre-pandemic baseline average of 3,600 per week.

It was also reported that hospitals and poison control centres across the US are treating a growing number of patients taking the drug, including hospitalisations and those who have had "altered mental statuses”.

Some people in the US have purchased the drug from veterinary supply stores and possibly consumed it in large doses meant for livestock.

The US Food and Drug Administration (FDA) said on its website that it has not authorised or approved ivermectin for use in preventing or treating Covid-19 in humans or animals.

"Currently available data do not show ivermectin is effective against Covid-19,” the FDA said, adding that clinical trials are underway to assess the efficacy of the drug.

FDA added that taking large doses of ivermectin is dangerous, and that if a doctor writes an ivermectin prescription, the patient should "take it exactly as prescribed”.

Overdosing on ivermectin can cause symptoms such as nausea, vomiting, diarrhoea, hypotension, allergic reactions, seizures, coma and even death, FDA said. — TODAY