Antibiotics are medications used to treat bacterial infections. They work by killing bacteria or stopping them from multiplying and are ineffective against viruses【3393203479394†L51-L54】.
Explanation
Antibiotics target specific bacterial processes to cure infections. Some, such as β‑lactams and glycopeptides, interfere with synthesis of the bacterial cell wall; others, such as aminoglycosides, macrolides and tetracyclines, bind to ribosomal subunits to halt protein synthesis. Fluoroquinolones inhibit DNA replication, and sulfonamides block folate metabolism. Based on their mode of action, antibiotics are classified as bactericidal—drugs that kill bacteria—or bacteriostatic—drugs that inhibit growth. They are further grouped by chemical structure into classes like aminoglycosides, β‑lactams, macrolides and tetracyclines【3393203479394†L72-L116】. Antibiotics are prescribed to treat a wide range of bacterial diseases, from urinary tract infections and pneumonia to sepsis. They must be taken as directed, because improper dosing or stopping treatment early allows surviving bacteria to adapt and develop resistance【3393203479394†L64-L67】.
Common classes and uses
β‑lactam antibiotics include penicillins, cephalosporins, carbapenems and monobactams; they disrupt peptidoglycan synthesis and are effective against many Gram‑positive and some Gram‑negative bacteria. Aminoglycosides, such as gentamicin and amikacin, are bactericidal agents used for serious infections caused by aerobic Gram‑negative bacilli. Macrolides, including erythromycin and azithromycin, are often used for respiratory tract infections and some sexually transmitted infections. Tetracyclines are broad‑spectrum agents used for atypical organisms like chlamydiae and rickettsiae, while fluoroquinolones, such as ciprofloxacin, are effective for urinary tract and gastrointestinal infections. Newer agents like oxazolidinones and lipopeptides target resistant organisms.
Antibiotics have revolutionised medicine, saving countless lives. Their benefits depend on responsible use, accurate diagnosis and adherence to prescribed regimens.
Related Terms: Antimicrobials, Antibacterials, Bactericidal, Bacteriostatic, Spectrum of activity