If the immune system is unable to deal with the invasion into the body of pathogenic bacteria, antibiotic drugs might be prescribed. There are many types of antibiotics that act on bacteria, including: the Aminoglycosides (eg. Gentamycin and Streptomycin), Chloramphenicol, Cephalosporins, Penicillins (eg. Amoxicillin), and the Tetracyclines.
In the past, antibiotic drugs were often prescribed for viral conditions, such as the common cold and viral sore throats, despite being ineffective against viruses. The resulting overuse is one of the factors contributing to antimicrobial resistance.