COVID-19 lessons for medical practice. Methylene blue is a time-tested innovation

Abstract

Significance of methylene blue (MB) in therapy of methemoglobinemia, malaria and urinary tract infections (UTI) is well known. The antimicrobial, anti-inflammatory, and antioxidant effect of MB has been demonstrated in different in vitro and in vivo studies. Necessity to find the remedy against COVID-19 attracted the interest of investigators and general practitioners to MB worldwide. The review includes various experiences of MB use, in particular in the patients treated with MB during the COVID-19 epidemic with a preventive effect, as well as own experience on this topic. MB is widely used as a dye in a variety of biological sciences applications — diagnostic procedures and the treatment of multiple disorders, including cyanide, and carbon monoxide poisoning, and is considered to be nontoxic. The beneficial effects of MB in the management of patients with multiple small renal calculi, especially with infected stones, and prevention of new stone formation were presented in a 5-year study. Moreover, due to MB antifungal potential and antimicrobial effect, it reduces symptoms of UTI, improves quality of life and could prevent the recurrence of disease. The patented complex of MB with sage leaf extract and American cranberry fruit extract (Pembina Blue®) demonstrated significant reduction of pain and spasm in cystitis patients. Given the limited number of available UTI therapies with concomitant increase in drug resistance, the demand for the search of new safe and effective UTI treatments are inevitable. Considering the fact that MB is FDA-approved compound that is already used for various therapeutic options, and also owing to the distinct antioxidant, antifungal, antibacterial and anti-inflammatory mechanisms presented in this review, MB could be considered as a promising drug for future.