Key definitions

• Antibiotics: a drug used to treat or prevent infection caused by microorganisms
• Bacteriostatic: inhibit growth of bacteria
• Bactericidal: kill bacteria

Antibiotics that act on the bacterial cell wall

• Inhibit cell wall synthesis by preventing cross linking of peptidoglycan - bactericidal

Penicillins e.g. flucloxacillin, amoxicillin

• β lactam
• Very few side effects
• Range from narrow to broad spectrum
• Excreted (rapidly) via kidneys
• Safe in pregnancy

Cephalosporins e.g. cefaclor, cefadroxil and cefalexin

• Modified β lactam
• Excreted via kidneys and urine
• Safe in pregnancy

Glycopeptides e.g. vancomycin

• Not absorbed when given orally - have to be administered IV
• Side effects: vancomycin damages kidneys, occasionally causes ‘red man syndrome’ (allergy)

Antibiotics that inhibit protein synthesis