A person with a physical health condition with altered pathologies

A community nurse is visiting Charlie Brooks, a 65-year-old man with chronic obstructive pulmonary disease (COPD) to assess a wound. While discussing his medication, Charlie shows the nurse a box of medicines which includes two half full packets of Amoxicillin. Charlie says he is often prescribed these when his COPD gets worse. He stops taking them when he feels better and keeps them in case, he needs them in the future.

What are the indications for, usual doses, side effects and relevant cautions for Amoxycillin?
How does it work?
Why is it important for Charlie to continue taking the prescribed course?
What actions might the nurse take to promote concordance?