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The Jury is Still Out on Ivermectin
Why the new ivermectin study doesn’t tell us much about whether the drug is effective for Covid-19
Ah, ivermectin. Before the pandemic, if you’d asked whether I was going to be spending much of my life writing about a drug mostly used to control endemic parasitic disease in Africa, I would’ve just been very confused.
But people are still arguing about it, so here we are.
A new large, controlled, randomized ivermectin study has come out, and depending on who you ask it either means that ivermectin works perfectly or has little to no benefit at all. Given that ivermectin remains the most hotly-debated topic of the last few years (coming second only to whether Britney Spears was unfairly treated), the new randomized trial seems pretty important.
Unfortunately, in reality, this study gives us very little information about ivermectin and doesn’t answer our most important questions at all.
The Science
The study itself, called I-TECH, is quite a good piece of research — the Malaysian authors allocated 500 high-risk patients with mild to moderate Covid-19 who had symptoms for less than a week randomly to either get ivermectin or a matched placebo control, and followed them up for 28 days. The pre-registered primary outcome measure was how many people had progressed from mild/moderate to severe disease in that time-period. Against this main outcome, the researchers found that people who were given ivermectin were more likely to get very sick than those given a placebo, although the difference was not statistically significant.
At a glance, this seems quite straightforward — the study found no benefit for ivermectin on its primary, pre-registered outcome, and that’s the one we care about most (for a number of important reasons). However, if you look back at that table, you’ll notice something very interesting. The…
