Antibiotics are the chemical compound or drugs that act against the survival of the offending living organism. They can be directed against bacteria, protozoa or parasites; the anti-viral drugs are not considered as antibiotics. Most of the antibiotics we use are against the bacteria, or also called antibacterial. 

Based on their action, they are bactericidal and bacteriostatic. Bactericidal are the drug which kill the organism, i.e. complete wash-out of the organism, while bacteriostatic drug are the one which render the bacteria passive, i.e. they are incapable of multiplication, and gradually fade in number. 

Antibiotics are powerful medicines that fight certain infections and can save lives when used properly. Antibiotics either stop bacteria from reproducing or destroy them. Since they are potent drugs they must be use judiciously. Off late antibiotics are being overused, this overuse is contributing toward the growing number of bacterial infections that are becoming resistant to antibacterial medications.

When a bacterium is found to be resistant to a particular antibiotic, then a higher or second-line drugs are prescribed, this resistance has to be prevented to that we do not run out off drug, as of now the last-line drugs carbapenems are in use. Drug-resistance can be prevented by strictly following the drug regime for stipulated duration and not giving up amidst. 

These antibiotics are usually used for infections such as lower respiratory tract, urinary tract, gastro-intestinal tract, skin and more. There are broad-spectrum antibiotics effective against few types of bacteria, while narrow-spectrum antibiotics are effective against a specific type of bacteria. In certain conditions, antibiotics are given prior to infection as a prevention of the forthcoming infection; these are called prophylactic antibiotic treatment.

-Koya Satyasri