I hope you have recovered from your fever.
To answer your question, amoxicillin is a penicillin-based antibiotic. It is used for treating bacterial infections of lungs (upper and lower respiratory tracts), ear infections, sinus, soft tissue and also skin infections. Many doctors also prescribe it for genitourinary infections such as bladder infections, stomach ulcers, and gonorrhea among others.
Amoxicillin treats a patient by interfering with the bacteria’s ability to form cell walls. These cell walls are vital for bacteria to survive. The cell walls help in keeping away unwanted substances from entering in while at the same time stopping the contents from leaking. Amoxicillin damages the bonds which hold the cell walls together. This results in the development of holes in the cells which allows medicines to get in and destroy the bacteria.
Your GP must have considered many reasons before choosing amoxicillin for you. One of the main reasons might be broader anti-bacterial actions that amoxicillin can perform compared to penicillin. It is also soft on the stomach when compared to Erythromycin. Also, amoxicillin does not stain teeth like Tetracycline.