Seeing her baby’s brown eyes turn indigo blue from one day to the next is what a mother in Thailand experienced when taking her 6-month-old son to the hospital for Covid-19. The child received an antiviral drug, favipiravir, which has been widely used in Asia in patients infected with SARS-CoV-2.
A few hours after starting treatment, the child’s eye color changed dramatically, enough to be described in the scientific journal Frontiers in Pediatrics. This clinical case raises a question that intrigues many parents: how can a drug against Covid-19 turn, even temporarily, a baby’s eyes blue?
In 18 hours, this baby’s brown eyes turn bright blue
When he arrived at the emergency room, the infant had a fever and a cough for 24 hours; an antigen test confirms” infection with SARS-CoV-2. In accordance with the recommendations of the Thai Ministry of Health, doctors prescribe
favipiravirin the form of tablets then syrup, for five days of planned treatment.
© Frontiers Pediatrics
COVID-19 treatment changes infant’s eye color
Eighteen hours after the first dose, the mother noticed that her baby’s brown eyes suddenly looked blue, especially in the sunlight. Doctors note a bluish discoloration of the corneawithout abnormal color of the skin, nails or mucous membranes. The respiratory symptoms improved in three days, but the team preferred to stop the antiviral out of caution.
Favipiravir: the antiviral against Covid-19 at the heart of the matter
Favipiravir is an antiviral initially developed for severe influenza, which targets the RNA polymerase of viruses. At the start of the pandemic, it was widely used against
Covid-19 in China, then adopted in Thailand as a reference oral treatment in children with mild to moderate disease, even if its overall effectiveness remains debated.
The most common adverse effects are digestive or biological, such as diarrhea, moderate hyperuricemia (increase in blood uric acid levels) or a drop in certain white blood cells, and represent approximately 20% of reported events. Much rarer eye disorders have been described: transient blurred vision, ocular surface fluorescence, and now this bluish cornea in an infant, the youngest patient reported to date.
An “extremely rare” side effect, but monitored in children
In their report, the doctors indicate that the color of the eyes returned to normal five days after stopping favipiravir and that an examination carried out two weeks later showed no eye damage. They argue that “This side effect could be due to the drug, its metabolites, or other excipients in the tablet, such as titanium dioxide and iron oxide yellow.“, they wrote in Frontiers in Pediatrics.
Favipiravir has already caused such a change observed by doctors. Another case, published in the Indian Journal of Ophthalmology in 2021, described the case of a 20-year-old man whose eyes changed from brown to blue on the second day of treatment. Again, his eyes returned to their normal color the day after stopping the medication. Another study also reported that researchers found that favipiravir could also cause… fluorescence in hair and nails.
© Indian Journal of Ophthalmology
“Although favipiravir is currently the gold standard oral antiviral treatment in children with Covid-19, its safety profile in growing children remains uncertain. Therefore, long-term monitoring of the safety of favipiravir in pediatric patients is paramount.“, they emphasize, calling for new studies on possible corneal after-effects.