ANTIBIOTICS: How much is too much?

My 10-year old and my 4-year old both do great when they are on antibiotics such as Bactrim or Zyvox. Their coughs almost disappear. However, 24 to 48 hours after they get off the antibiotics, their coughs return. They both only culture MRSA. What I want to know is what issues are caused by just putting them on these antibiotics every couple of weeks and are these issues bigger than not putting them on these antibiotics every two weeks. Thoughts?
Source: Cystic Fibrosis Families Forum - Category: Respiratory Medicine Authors: Tags: Families Source Type: forums