1. evidence of critical covid-19 based on any of the following * admission to icu * assisted ventilation (invasive or non-invasive) * ecmo or hemofiltration required * ards * shock * acute cardiac failure 2. dementia 3. bacterial co-infection 4. co-infection with other common viral pneumonias (e.g. influenza) 5. participation in another interventional clinical trial or intention to participate in another interventional study during the course of this study; 6. in the opinion of the investigator, unlikely to survive for at least 48 hours from screening or anticipate mechanical ventilation within 48 hours 7. unable to take oral medication 8. history of gastrointestinal illness that may cause nausea and vomiting 9. subjects with any laboratory test at screening that common medical practice would deem as significantly abnormal. for example: * alanine transaminase (alt), aspartate transaminase (ast), or alkaline phosphatase \>5.0 times the upper limit of normal (uln) or * creatinine clearance \<30 ml/min 10. the subject has a known allergy or sensitivity to the study treatment or to any of the excipients contained in the study drug formulation (see list of ingredients in the investigator's brochure); 11. female subject with a positive pregnancy test or nursing, or planning a pregnancy during the course of the study; 12. unwilling or unable to comply with study requirements

1. evidence of critical covid-19 based on any of the following * admission to icu * assisted ventilation (invasive or non-invasive) * ecmo or hemofiltration required * ards * shock * acute cardiac failure 2. dementia 3. bacterial co-infection 4. co-infection with other common viral pneumonias (e.g. influenza) 5. participation in another interventional clinical trial or intention to participate in another interventional study during the course of this study; 6. in the opinion of the investigator, unlikely to survive for at least 48 hours from screening or anticipate mechanical ventilation within 48 hours 7. unable to take oral medication 8. history of gastrointestinal illness that may cause nausea and vomiting 9. subjects with any laboratory test at screening that common medical practice would deem as significantly abnormal. for example: * alanine transaminase (alt), aspartate transaminase (ast), or alkaline phosphatase \>5.0 times the upper limit of normal (uln) or * creatinine clearance \<30 ml/min 10. the subject has a known allergy or sensitivity to the study treatment or to any of the excipients contained in the study drug formulation (see list of ingredients in the investigator's brochure); 11. female subject with a positive pregnancy test or nursing, or planning a pregnancy during the course of the study; 12. unwilling or unable to comply with study requirements

evidence of critical covid-19 based on any of the following admission to icu assisted ventilation (invasive or non-invasive) ecmo or hemofiltration required ards shock acute cardiac failure dementia bacterial co-infection co-infection with other common viral pneumonias (e.g. influenza) participation in another interventional clinical trial or intention to participate in another interventional study during the course of this study; in the opinion of the investigator, unlikely to survive for at least 48 hours from screening or anticipate mechanical ventilation within 48 hours unable to take oral medication history of gastrointestinal illness that may cause nausea and vomiting subjects with any laboratory test at screening that common medical practice would deem as significantly abnormal. for example: alanine transaminase (alt), aspartate transaminase (ast), or alkaline phosphatase >5.0 times the upper limit of normal (uln) or creatinine clearance <30 ml/min the subject has a known allergy or sensitivity to the study treatment or to any of the excipients contained in the study drug formulation (see list of ingredients in the investigator's brochure); female subject with a positive pregnancy test or nursing, or planning a pregnancy during the course of the study; unwilling or unable to comply with study requirements

evidence of critical covid-19 based on any of the following admission to icu assisted ventilation (invasive or non-invasive) ecmo or hemofiltration required ards shock acute cardiac failure dementia bacterial co-infection co-infection with other common viral pneumonias (e.g. influenza) participation in another interventional clinical trial or intention to participate in another interventional study during the course of this study; in the opinion of the investigator, unlikely to survive for at least 48 hours from screening or anticipate mechanical ventilation within 48 hours unable to take oral medication history of gastrointestinal illness that may cause nausea and vomiting subjects with any laboratory test at screening that common medical practice would deem as significantly abnormal. for example: alanine transaminase (alt), aspartate transaminase (ast), or alkaline phosphatase >5.0 times the upper limit of normal (uln) or creatinine clearance <30 ml/min the subject has a known allergy or sensitivity to the study treatment or to any of the excipients contained in the study drug formulation (see list of ingredients in the investigator's brochure); female subject with a positive pregnancy test or nursing, or planning a pregnancy during the course of the study; unwilling or unable to comply with study requirements

1. evidence of critical covid-19 based on any of the following - admission to icu - assisted ventilation (invasive or non-invasive) - ecmo or hemofiltration required - ards - shock - acute cardiac failure 2. dementia 3. bacterial co-infection 4. co-infection with other common viral pneumonias (e.g. influenza) 5. participation in another interventional clinical trial or intention to participate in another interventional study during the course of this study; 6. in the opinion of the investigator, unlikely to survive for at least 48 hours from screening or anticipate mechanical ventilation within 48 hours 7. unable to take oral medication 8. history of gastrointestinal illness that may cause nausea and vomiting 9. subjects with any laboratory test at screening that common medical practice would deem as significantly abnormal. for example: - alanine transaminase (alt), aspartate transaminase (ast), or alkaline phosphatase >5.0 times the upper limit of normal (uln) or - creatinine clearance <30 ml/min 10. the subject has a known allergy or sensitivity to the study treatment or to any of the excipients contained in the study drug formulation (see list of ingredients in the investigator's brochure); 11. female subject with a positive pregnancy test or nursing, or planning a pregnancy during the course of the study; 12. unwilling or unable to comply with study requirements

1. evidence of critical covid-19 based on any of the following - admission to icu - assisted ventilation (invasive or non-invasive) - ecmo or hemofiltration required - ards - shock - acute cardiac failure 2. dementia 3. bacterial co-infection 4. co-infection with other common viral pneumonias (e.g. influenza) 5. participation in another interventional clinical trial or intention to participate in another interventional study during the course of this study; 6. in the opinion of the investigator, unlikely to survive for at least 48 hours from screening or anticipate mechanical ventilation within 48 hours 7. unable to take oral medication 8. history of gastrointestinal illness that may cause nausea and vomiting 9. subjects with any laboratory test at screening that common medical practice would deem as significantly abnormal. for example: - alanine transaminase (alt), aspartate transaminase (ast), or alkaline phosphatase >5.0 times the upper limit of normal (uln) or - creatinine clearance <30 ml/min 10. the subject has a known allergy or sensitivity to the study treatment or to any of the excipients contained in the study drug formulation (see list of ingredients in the investigator's brochure); 11. female subject with a positive pregnancy test or nursing, or planning a pregnancy during the course of the study; 12. unwilling or unable to comply with study requirements