I Repeat, Hydroxychloroquine Doesn't Work (For Now)

Why the drug is unlikely to be beneficial to Covid-19 patients and could carry potential risks

- Dr. Edsel Maurice T. Salvana

Game changer! The missing ingredient! No more lockdowns needed! These headlines scream for attention from newspapers and webpages on a regular basis. Some people share them, and some go viral. While most are eventually debunked and lose steam, a few develop a life of their own and continue to resurface even after repeated explanations from health authorities and science experts.

Part of the problem is that people can misunderstand how science works. Science is a messy process with a hierarchy of proof. Evidence for efficacy builds from the study before it. The smaller, older studies become the basis for the performance of bigger, newer, more extensive studies. If at any point the bigger study fails, then the smaller studies are not enough to overturn the findings of the bigger study since the bigger studies are typically better designed. The bigger studies are less likely to be biased or confounded by extraneous factors.

Drug development research goes through multiple stages. First come in-vitro or laboratory studies, and animal studies. Then studies on humans are done. Phase one studies test safety. Phase two studies look for the best dose while continuing to look at safety. Phase three studies are the randomized controlled trials (RCTs), which prove safety and efficacy. Phase four is a post-approval study, which continues to look for safety issues as the drug is used in clinical practice.

If a drug fails at phase one, there won’t be a phase two unless a revised phase one shows safety. Some evidence of efficacy in phase two will not be able to overturn lack of efficacy in phase three, because phase two isn’t designed to measure efficacy properly. If there is doubt about a negative finding from a phase three, then a new phase three can be done with different parameters.