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
Ampicillin + gentamicin is an example of what type of antimicrobial combination?
Why?
Used in which infections?
Synergism
Ampicillin damages cell membranes and allows the aminoglycoside to enter the cell
endocarditis
Common antagonistic combination of antibiotics
ERY + DA
What is an additive effect?
The combination has an effect which is equal to the sum of the two different drugs - no more, no less
What are the big 5 genes responsible for ESBL production?
“VONKI”
VIM
OXA-48
NDM
KPC
IMP
