May not work mean he isn't even sure if you have LTRI and if you...

May not work mean he isn't even sure if you have LTRI and if you do have LTRI then this will get worst in 3-4 days which mean you will need to take more days of work and at worst develop into pneumonia which mean even more time off work and possible hospitalisation, that's why usually doctor will just prescribe antibiotic anyway which isn't providing the best care for their patients is it.....probable benefit vs probable risk there don't you think.