Antibiotik

An antibiotic, or antibiotics (antibiotik in some languages), is a substance that kills bacteria or inhibits their growth. They can be natural products produced by microorganisms, or synthetic or semi-synthetic compounds designed to target bacteria while limiting harm to the host. Antibiotics are used to treat bacterial infections and are distinct from antiviral or antifungal drugs.

Most antibiotics work by interfering with essential bacterial processes. They can be bactericidal, meaning they kill bacteria, or bacteriostatic, meaning they stop bacteria from multiplying. Major classes include beta-lactams (such as penicillins and cephalosporins) that inhibit cell wall synthesis; macrolides and lincosamides that inhibit protein synthesis; tetracyclines; aminoglycosides; fluoroquinolones that inhibit DNA replication; glycopeptides; sulfonamides; and polymyxins. Some have broad spectrum activity, affecting many species, while others are narrow spectrum.

Antibiotics are prescribed for a range of bacterial infections, including pneumonia, skin infections, urinary tract infections, and sexually transmitted infections. They are not effective against viral illnesses such as influenza or the common cold. Proper use, including completing prescribed courses and avoiding unnecessary use, is essential to reduce harm and maintain effectiveness.

Resistance to antibiotics is a major global challenge. Bacteria can acquire resistance through mutation or gene transfer, and misuse accelerates this process. Infection control, vaccination, surveillance, and antibiotic stewardship aim to preserve antibiotic effectiveness. Common adverse effects include allergic reactions, stomach upset, and disruption of the gut microbiota; some agents interact with foods or other medicines.