cefachlor - what is it?

[Frame Ok]

I am taking a pathogenic microbiology class at the University of 
Maryland, and on top of finals, we have been given a clinical unknown to 
identify and treat.  

my theoretical patient is a 2 year old with otitis media.  the child was 
first put on ampicillin, but there was no response to it.  The antibiotic 
has been switched to cefachlor, and has improved the patient's condition.

in our class lecture, we had a specific antibiotic lecture, but i don't 
remember cefachlor being discussed.  could someone briefly tell me what 
sort of antibiotic it is, and how it works?

thanks a lot...
/meagan