My mother has had strenum soreness and a low grade fever for almost a week.. The dr, prescribed a zpack for 3 days. She took the first pill at lunch. Tonight her fever is even higher and now she has a bad sore throat . Do we just need to wait for the antibotic to kick in or does it seem like something different. She was seen by the dr. when she first got sick a week ago but she wasnt having fever then, just sore sternum.