Fluorescence of ocular surface in a Covid -19 patient after Favipiravir treatment: a case report

Abstract

Background Favipiravir is used in treatment of Covid-19 patients. We aimed to share of ocular surface fluorescence in a patient after Favipiravir treatment in this case report. Case presentation A 20-year-old male patient declared no known systemic disease prior to Covid-19. He applied to us with blurry vision and blue light reflection after Covid-19 treatment with Favipiravir. We observed bilateral fluorescence on his eyes and fluorescence of his nails. Biomicroscopic examination was insignificant. Conclusion We investigated the fluorescence of favipiravir tablets under ultraviolet light. Drug demonstrated fluorescence. We recorded the favipiravir fluorescence in-vitro. This appears to be a strong evidence in terms of the linkage between the fluorescence of the ocular surface and favipiravir.

Case report: Favipiravir-induced bluish corneal discoloration in infant with COVID-19

“…Studies have shown that the active phosphorylated metabolite of favipiravir is found in human plasma and that there is a linear correlation between its concentration and the intensity of fluorescence ( 16 ). In subsequent laboratory investigations ( 15 ), fluorescence characteristics of favipiravir tablet were examined under ultraviolet light, and the observations confirmed the fluorescence of the drug, which signified a robust association between the fluorescence of the ocular surface and favipiravir. Additionally, a direct relationship was found between the concentration of favipiravir and fluorescence intensity within a specific range (40–280 ng/ml).…”

“…Mild hyperuricemia, diarrhea, and neutropenia were the most frequently reported side effects and accounted for 20% of all adverse events ( 9 ). Furthermore, several rare adverse effects have been documented, including the bluish discoloration of the cornea ( 10 ), temporary visual blurring ( 15 ), and fluorescence of the ocular surface ( 15 ). However, these adverse reactions were observed to have resolved after discontinuation of the medication, as reported by Raiturcar et al who documented the restoration of normal corneal color within a day ( 10 ).…”

“…In addition to the potential for corneal discoloration, favipiravir has also been shown to cause fluorescence in human hair and nails ( 16 ). This adverse effect may be due to the drug, its metabolites, or additional tablet components such as titanium dioxide and yellow ferric oxide ( 10 , 15 ). Studies have shown that the active phosphorylated metabolite of favipiravir is found in human plasma and that there is a linear correlation between its concentration and the intensity of fluorescence ( 16 ).…”

Luminescence of favipiravir in skin appendages and sclera. A controlled study and literature review

“…Doran et al 12 reported on a patient with whole ocular surface fluorescence liable to favipiravir intake. Their patient was a photographer and detected the fluorescence phenomenon by himself.…”

An unusual case of bluish discoloration of the cornea after favipiravir therapy for COVID-19

“…[ 3 ] Recently in April 2021 Doran et al . [ 4 ] reported a case where a 20-year-old photographer who was started on favipiravir presented on the second day of therapy with blurred vision and blue light reflection when he was exposed to UV light sources at his workplace. On examination, they noticed fluorescence of his corneas and nails under Wood’s lamp, but no bluish discoloration of cornea was noted and slit-lamp biomicroscopy was not significant.…”