Clinical Application of Methylene Blue for Treatment of Covid-19 Patients

Inclusion Criteria: 1. Confirmed case of Covid-19 (by RT-PCR, HRCT) 2. Admission to Intensive Care Unit 3. Need for intubation and mechanical ventilation (PaO2/FiO2 \< 100-200) 4. Written informed consent Exclusion Criteria: 1. Pregnancy and breastfeeding 2. History of G6PDH deficiency 3. Preadmission anticoagulation 4. Severe renal insufficiency (glomerular filtration rate \<30 mL/min/1.73m2) 5. Medical records of cirrhosis 6. Active chronic hepatitis 7. Severe hepatic disease defined by GOT or GPT levels three times above the normal upper limit 8. Patients with history of allergic reaction or significant sensitivity to Methylene blue 9. Treatment with immunosuppressive agents 10. Use of other investigational drugs in the moment of inclusion