The story of a 6-month-old boy in Bangkok whose eyes turned blue after COVID-19 antiviral treatment is a fascinating one. It raises questions about the potential side effects of medications and the importance of thorough research and monitoring. This case, reported in the journal Frontiers in Pediatrics, highlights the unexpected and sometimes bizarre outcomes of medical treatments. The boy's eyes, which were normally dark brown, turned bluish-purple about 18 hours after he began taking favipiravir tablets and liquid. This wasn't the first time this had happened. A year earlier, in Goa, India, a 20-year-old man developed a similar bluish tinge in his corneas after starting favipiravir treatment for COVID-19. This side effect had never been documented before, and the doctors advised him to stop taking the drug, which resolved the issue the next day. But what makes this case unique is that it involved a pediatric patient, and the discoloration took several days to disappear. The doctors suspected that the blue tint was caused by the favipiravir, which is known to release fluorescent chemicals that collect in the cornea. This was supported by a study in Turkey, where four female COVID-19 patients developed a glowing blue-green tint in their hair and fingernails after taking favipiravir. The Turkish researchers found fluorescence in whole tablets and those dissolved in water, suggesting a strong link between the drug and the discoloration. The child's symptoms improved after three days of treatment, and the pediatrician advised discontinuing the drug on the fifth day. The corneas returned to their normal color five days later, and an ophthalmologist found no signs of bluish color or fluorescence two weeks later. The doctors proposed that the patient's age and medication dosage could be factors in the delayed resolution of the discoloration. They also suggested that the baby's reduced urination, a potential side effect of favipiravir, may have contributed to the compounds affecting his eye color lingering in his tissues. While side effects of favipiravir are uncommon, they can include diarrhea, high levels of uric acid, and lower levels of neutrophils. Other less-common side effects include abdominal pain, nausea, and low platelet levels. This case serves as a reminder that even seemingly minor side effects can have significant impacts, and thorough research and monitoring are essential in medical treatments. It also highlights the importance of reporting and documenting unusual side effects to ensure patient safety and inform future medical practices.
