GDC pharm immunedrugs  Pharmacology: Pharmacology of
Antibacterial Drugs
• bactericidal antibiotics- kill bacteria
• bacteriostatic antibiotics- slow bacteria proliferation by lowering divisions
• Targets for bacteria:
o Cell wall synthesis or destruction
gram positive: peptidoglycan (stains purple)
gram negative: lipopolysaccharide (stain pink)
mycobacteria: mycolic acid
fungi: ergosterol cell wall composition
beta-lactams (penicillin, cephalosporins)

bind to “penicillin binding site” D-alanine- D-
alanine

penicillin allergy (act as haptens and produce
immune response)
vancomycin (for MRSA, C.diff)
polymyxins (gram negative)
anti-mycobacterials- ethambutol.

o Nucleic acid synthesis
Nucleoside/ nucleotide synthesis inhibitors
similar structure to folic acid, so inhibit first enzyme in
folic acid synthesis (can lead to megaloblastic anaemia)

DNA gyrase inhibitors
quinolones- interfere with topoisomerase II
UTI, E.coli, Shigella, Salmonella, Campylobacter
RNA polymerase inhibitors
broad spectrum, bacteriostatic
rifampicin
hepatotoxic (rarely)

o Protein synthesis (inhibit 30S/50s ribosomes)
Tetracyclines
prevent amino-acyl tRNA binding
bacteriostatic
absorbed orally on empty stomach, with metal ions
for intracellular parasites (cholera, plague, lymes)
Aminoglycosides
bactericidal
gram negative, sepsis, bowl surgery
Chloramphenicol
inhibit transpeptidation
bacteriostatic
excellent absorption including CNS (for meningitis)
used for life-threatening infections of respiratory tract,
ear, sinuses, meninges where there is resistance to other
drugs
Macrolides

GDC Pharmacology: Pharmacology of
Antibacterial Drugs
inhibit translocation
bactericidal or bacteriostatic
doesn’t enter CNS
treat legionella

grey baby syndrome, cn8, deafness, contact dermitis, abx,