Question: The President has not been touting hydroxychloroquine as much these days. Do we know more about how well the drug is working as treatment?
Answer: We’ll know much more once the clinical trials rigorously testing hydroxychloroquine are complete. In the meantime, the most recent and complete data we have are not promising.
A week ago, results from a Brazilian study on high dose hydroxycholoroquinee for COVID-19 treatment were released (again, pre-print, not yet peer reviewed). The study examined whether clinical outcomes were improved with a higher dose of hydroxycholoroquine compared with a lower dose. The study was stopped early because of the adverse outcomes (much higher risk of death) associated with the higher dose. These findings show that hydroxycholoroquine in too high a dose can be extremely harmful. But the findings don’t tell us about the impact — positive or negative — of a lower dose. Cue new study.
Just today, researchers released a pre-print manuscript submitted to the New England Journal of Medicine that explores outcomes of 368 male COVID-19 patients in the VA system who either received A) hydroxycholoroquine; B) hydroxycholoroquine + azithromycin; C) neither. The study used retrospective VA system record review and adjusted for myriad confounding factors. In fact, because patients who received an intervention (e.g. hydroxycholoroquine +) were more likely to have severe disease (and therefore more likely to die), the researchers used propensity score matching to help ensure that the comparisons between the groups were fair. That’s maybe a wee too science-y. What I’m trying to say is that the researchers did a really good job to try and make sure that the comparisons across the three groups really were comparisons of the impact of hydroxycholoroquine rather than some other factor or set of factors. And they found that the risk of death was highest among the Group A (adjusted hazard ratio, 2.61; 95% CI, 1.10 to 6.17; P=0.03). This was a statistically significant finding (e.g. very, very small chance that it’s not due to random error). Hydroxycholoroquine was not associated with improved outcomes but instead, was associated with increased risk of adverse outcomes! Soapbox moment — it’s findings like these and science like this, which highlight the need for clinical trials and evidence(!) before widespread use of a given drug.