I assume those are being given by docs.The antibiotics and malaria meds wouldn't do anything to makes things worse then?
Chronic lung disease so they gave him antibiotics in case he has a secondary infection like pneumonia. This is shotgun approach but the guy has a worsening case so they trial antibiotics to see if he gets better while they await cultures.
The antimalarial drug is probably plaquenil which has been reported in some case reports to be helpful and disease modulating the viral infection.