Antibiotics Flashcards
learn abx groupings and mechanisms
Cell wall synthesis> B lactams> carbapenems
list 3
imipenem
ertapenem
meropenem
Cell wall synthesis>B lactams>Penicillins
list:
-1 narrow spectrum
- 2 broad spectrum
Narrow: Penicillin
Broad: amoxicillin, ampicillin
Cell wall synthesis: B lactams>Cephalosporins
list one for each generation
- cephalexin
- cefoxitin, cefuroxime
- cefpodoxime, ceftazidime, cefotaxime, ceftriaxone, cefixime
- cefepime
- ceftaroline
Cell wall synthesis> no B-lactam> glycopeptides
List 2
Vancomycin
Teicoplanin
(Polymixin B)
Side effects of Vancomycin?
ototoxicity/nephrotoxicity
Protein synthesis affecting antibiotics are bacteriostatic except for….
Aminoglycosides
Protein synthesis> 30S subunit> tetracyclins
list 2
tetracycline
doxycycline
Protein synthesis> 30S subunit> aminoglycosides
list 4 and their side effects
Tobramycin
Amikacin
Neomycin
Gentamicin
ototoxic/nephrotoxic
Protein synthesis> 50S subunit> lincosamides
name one
clindamycin
Protein synthesis> 50S subunit> macrolides
name 3
Erythromycin
Azithromycin
Clarithromycin
What is MLSBi?
Which enzyme is involved?
Which antibiotics?
Inducible macrolide-lincosamide-streptogramin B resistance.
Erythromycin induces clindamycin resistance via inducing methylase enzyme
Which antibiotics which affect protein synthesis are bacteriostatic?
Tetracyclins: TET, DOX
Macrolides: ERY, AZI, CLR
Lincosamides: DA
Linezolid and chloramphenicol
Which antibiotic is excreted through the urinary tract rather than removed by the liver?
Nitrofurantoin
DNA synthesis inhibitors> fluoroquinolones
list 3
Ciprofloxacin
Levofloxacin
Norfloxacin (used as indicator in Staphs)
DNA synthesis inhibitors> quinolones
name 1
Nalidixic Acid
Name two antibiotics which affect folic acid synthesis and the name of the effect when they are used together (e.g. additive, antagonistic, synergistic)
Sulphamethoxazole
+
trimethoprim
SYNERGY
Which antibiotic damages DNA directly?
MTZ
Which antibiotic interferes with mRNA synthesis?
Rifampicin
Name 3 ways bacteria can develop resistance to B-lactams
- B-lactamases
- mutations of PBPs
- altered porins
KESC group are always resistant to ampicillin/amoxicillin
True or false?
True - intrinsic resistance due to low permeability of cell wall
Van - A resistance infers which results for Vanc/Teic?
Vanc = R
Teic = R
Van - B resistance infers which results for Vanc/Teic?
Vanc = R
Teic = S
Can an enterococci be Van = S and Teic = R ?
NO - Both antibiotics are
glycopeptides, and resisistance
is determined by Van-A, Van-B
or Van-C genes. None of these
genes impart Teicoplanin
resistance AND Vancomycin
susceptibility. The profiles are:
Van-A (Vanc and Teic R), Van-B
(Vanc R, Teic S) or Van-C
(partial Vanc R)
Can Gram positive bacteria be susceptible to Colistin?
NO - Colistin targets lipopolysaccharides in Gram negative cell walls, so cannot act on Gram positives.
All GRam positive organisms are resistant to colistin
