Antibacterials

Question 1

inhibits incorporation of PABA into folic acid and reduction of DHF to THF
Resistance: plasmid for altered DHFR
Use: chronic bronchitis, otitis media in children, acute maxillary sinusitis in adults caused by H flu & S pneumoniae

Answer 1

Sulfonamides
Ex: Trimethoprim-sulfamethoxazole

can be used for Nocardia & P jirovecci in high dose

Question 2

MOA: binds to 50s or the ribosome and inhibits the translocation step, preventing chain movement from A site to the P site -> prevents protein synthesis
Use: mycoplasma, pertussis, legionella, diptheria
Better for gram + than gram -

Answer 2

erythromycin

Macrolide

Question 3

macrolides

Answer 3

-thromycin

erythromycin
telithromycin
clarithromycin
azithromycin

Question 4

beta-lactamase inhibitors

Answer 4

-bactam

tazobactam
sulbactam
clavulanic acid

Question 5

fluoroquinolones

MOA: Target DNA gyrase (negative supercoils) & topo IV (separates daughter strands)

Answer 5

-floxacin

Levofloxacin
Gatifloxacin
Moxifloxacin

Question 6

cephalosporins
MOA: inhibit bacterial cell wall synthesis like PCNs
modest activity against gram neg but 2+ gen better

4th gen good for nosocomial infections with antibiotic resistant beta lactamases

Answer 6

Cef-

Cefuroxime
Cefpodoxime proxetil (3)
Cefotaxime (3)
Ceftazidime (3)
Ceftriaxone = Rocephin (3)
Cefepime (4)