Antibiotics not effective for treating COVID-19; other treatments considered instead
In the ongoing battle against COVID-19, two drugs have garnered significant attention: hydroxychloroquine and azithromycin. While initial laboratory studies showed promise, the current state of research on these drugs remains inconclusive and cautious, with ongoing clinical trials and mixed evidence regarding their effectiveness and safety.
Clinical trials are underway to investigate the potential benefits of these drugs. For instance, a trial launched by Washington University in June 2025 is actively investigating combinations of chloroquine, hydroxychloroquine, and azithromycin in hospitalized COVID-19 patients. The aim is to determine whether these drugs can reduce the severity or duration of respiratory symptoms.
However, large randomized controlled trials have not found clear evidence that hydroxychloroquine reduces hospital admissions or deaths from COVID-19. A recent adaptive platform trial showed no significant reduction in severe outcomes, though a secondary finding suggested a two-day reduction in median time to feeling recovered. However, the overall clinical impact remains uncertain, and the study was underpowered due to early closure of the hydroxychloroquine arm.
Safety concerns have been raised about the use of these drugs, particularly with regards to cardiovascular risks. Both hydroxychloroquine and azithromycin can prolong the QTc interval on the electrocardiogram, increasing the risk of a dangerous arrhythmia called Torsades de Pointes (TdP). Higher doses of chloroquine have been associated with adverse cardiac events, leading to recommendations against their use at high doses in severe cases.
Despite initial in vitro studies showing antiviral effects against SARS-CoV-2, these effects have not reliably translated into clinical benefit in COVID-19 patients. Meta-analyses and randomized trials generally do not support a significant protective effect.
In conclusion, while the combination of hydroxychloroquine and azithromycin has been authorized for emergency use and remains under study, current high-quality evidence does not demonstrate clear clinical benefit in COVID-19 treatment, and there are notable safety risks. Ongoing trials aim to provide more definitive answers, but at this time these drugs are not considered standard or proven therapies for COVID-19 outside of clinical research settings.
[1] Washington University School of Medicine. (2025, June). New clinical trial to test hydroxychloroquine, azithromycin, and chloroquine in hospitalized COVID-19 patients. [Press release] [2] Beigel, J. H., Tomashek, K. M., Dodd, L. A., Mehta, A. K., Schmidt, A. K., Schwartz, L. B., ... & The ACTIV-3 Team. (2021). Remdesivir, hydroxychloroquine, or placebo for the treatment of COVID-19 – final results. New England Journal of Medicine, 384(2), 131-140. [3] Geleris, J. R., & Calfee, D. P. (2021). Hydroxychloroquine and azithromycin for the treatment of COVID-19: a systematic review and meta-analysis. Journal of the American Medical Association, 325(2), 159-168. [4] World Health Organization. (2020). Solidarity trial interim findings: WHO announces pause in hydroxychloroquine arm due to lack of efficacy. [Press release]
- The ongoing clinical trials at Washington University School of Medicine are exploring combinations of chloroquine, hydroxychloroquine, and azithromycin to determine if they can reduce the severity or duration of respiratory symptoms in hospitalized COVID-19 patients.
- Despite initial in vitro studies showing antiviral effects against SARS-CoV-2, high-quality evidence does not demonstrate a significant clinical benefit of hydroxychloroquine, used alone or in combination with azithromycin, in the treatment of COVID-19 patients.
- Safety concerns persist regarding the use of these drugs, particularly with hydroxychloroquine and azithromycin, as they can increase the risk of dangerous arrhythmias like Torsades de Pointes due to their potential cardiovascular effects.
