Amoxicillin, erythromycin, and other antibiotics treat bacterial infections by either eliminating bacteria or halting their growth. Using the right antibiotic for conditions like meningitis or skin infections ensures effectiveness and minimizes antibiotic resistance. 1 Antibiotics are medicines that help stop infections caused by bacteria. They do this by killing the bacteria or by keeping them from copying themselves or reproducing. The word antibiotic means. Myth: I can use leftover antibiotics from a previous illness. Fact: This is dangerous. The leftover antibiotic may not be the correct one for your current illness, and the dosage may be insufficient, leading to ineffective treatment and increased resistance. The chart below lists some of the antibiotic classes used in the U.S. along with examples of the individual medicines your provider might prescribe. These are just a few of the many available types your provider will choose from to meet your individual needs. Antibiotics are used to treat or prevent bacterial infections, [36] and sometimes protozoan infections. (Metronidazole is effective against a number of parasitic diseases). There is not one type of antibiotic that cures every infection. Antibiotics specifically treat infections caused by bacteria, such as Staph., Strep., or E. coli., and either kill the bacteria (bactericidal) or keep it from reproducing and growing (bacteriostatic). Antibiotics are medicines that fight bacterial infections in people and animals. They work by killing the bacteria or by making it hard for the bacteria to grow and multiply. Antibiotics can be taken in different ways: Orally (by mouth). This could be pills, capsules, or liquids. Topically. Antibiotics are medicines used to treat or prevent bacterial infections - they do not work against viral infections such as colds or the flu. They are usually prescribed for serious bacterial infections or if the immune system is weakened, though many infections can improve without them. Antibiotic, chemical substance produced by a living organism, generally a microorganism, that is detrimental to other microorganisms. Antibiotics came into worldwide prominence with the introduction of penicillin in 1941. Since then they have revolutionized the treatment of bacterial infections. Key points Antibiotics can save lives, but they aren't always the answer. Take these steps to use antibiotics appropriately so you can get the best treatment when you're sick, protect yourself from side effects caused by unnecessary antibiotic use and combat antimicrobial resistance.