Antibiotics Guide - choices for common infections. General principles of the right antibiotics prescribing: (1) Only prescribe antibiotics for bacterial infections if symptoms are signficant or severe, there is a high risk of complications, and the infection is not resolving (2) Use first-line antibiotics first (3) Reserve broad spectrum antibiotics for indicated conditions only. There is an excellent and comprehensive compendium of antibiotics guide available on the BPAC NZ website.