You are correct - it's an antibiotic.
N 114 500 is 500 mg
cephalexin. I think this is an older imprint.
http://www.drugs.com/mtm/Cephalexin.html
I'm not a pharmacist or a medical doctor. This message is not medical advice nor is it an offer to provide medical advice. All drug identifications should be validated by a licensed MD or pharmacist.