Health issues. I give him this in night?

My son 1.6yrs old, almost from 1.5 months suffering from cold, caugh, fever, loose motion, some time vommiting., diarrhea... It's randamly happening some time cold, caugh, some time other things... He was well before my daughter has cold, caugh, my son sleeping next to her.. He is 12kg, he is active... His blood 7.7.. I met famous 3-4doctors..(antibitic also given maxclev) 1 doctor told to blood transfusion.. But we don't want that as first preference. Others advised to give iron syrups.. Etc I searched google, found because of round warm, etc.. Caused to health issues like this. One doctor advised to give albendazale. Can I give him this in night? Inspite of caugh, cold, fever or let it stop.. Later can give it.. Please advise.. Why frequently this is happening to him.. We are doing nebulazation also.. Lot of caugh comes.. When he sleep also he gets disturbed... Please advise.. What shall I do.. I am fed up with medicines giving him everyday... Please help