Antibiotics: gross mechanism of action

The diagram and list below summarises the gross mechanism of action of the commonly used antibiotics. More detailed descriptions are found elsewhere on the site.




Inhibits cell wall formation

• peptidoglycan cross-linking: penicillins, cephalosporins, carbopenems
• peptidoglycan synthesis: glycopeptides (e.g. vancomycin)

Inhibits protein synthesis (by acting on the ribosome)

• 50S subunit: macrolides, chloramphenicol, clindamycin, linezolid, streptogrammins
• 30S subunit: aminoglycosides, tetracyclines

Inhibits DNA synthesis

• quinolones (e.g. ciprofloxacin)

Damages DNA

• metronidazole

Inhibits folic acid formation

• sulphonamides
• trimethoprim

Inhibits RNA synthesis

• rifampicin