In a notable advancement for long COVID management, a randomized controlled trial (RCT) published in Annals of Internal Medicine has demonstrated that the antidepressant fluvoxamine can significantly alleviate one of the most debilitating symptoms: persistent fatigue. Unlike the diabetes medication metformin, which showed no benefit, fluvoxamine led to steady improvements in fatigue scores and quality of life over 60 to 90 days, with a favorable side effect profile compared to placebo.

This RCT provides high-quality evidence due to its randomized, placebo-controlled design. The original source does not specify the sample size, which is a limitation in assessing the study's power, and conflicts of interest are not mentioned. Building on the 2022 TOGETHER trial published in The Lancet Global Health (an RCT with 1,497 participants showing fluvoxamine reduced hospitalization risk in acute COVID-19), this suggests consistent benefits across disease stages. What the original MedicalXpress coverage missed is fluvoxamine's sigma-1 receptor agonism that may reduce neuroinflammation and cytokine activity - patterns also seen in ME/CFS research where observational studies (typically n=30-100 with high risk of bias and occasional industry funding) have shown inconsistent results with antidepressants.

Synthesizing these with a 2023 review in Nature Medicine on long COVID mechanisms highlights that few treatments have strong evidence, making this repurposing particularly valuable as an accessible, low-cost option for millions. However, gaps remain in subgroup analysis, long-term outcomes beyond 90 days, and integration with non-pharmacologic approaches. While promising, clinicians should weigh individual risks given its SSRI profile.