Antibiotics Flashcards
Penicillins
cell wall synthesis inhibitor inhibits PCP (transpeptidase) which cross-links in the cell wall
PBP
Penicillin binding protein
Transpeptidase
Aminopenicillins
Cell wall synthesis inhibitors
competitively inhibit transpeptidase
Penicillinase resistant penicillins
cell wall synthesis inhibitors
competitively inhibit transpeptidase
Antipseudomonal penicillins
piperacillin
always paired with tazobactam
cell wall synthesis inhibitors
competitively inhibit transpeptidase
first gen cephalosporins
cell wall synthesis inhibitors; competitively inhibit transpeptidase
When do first gen cephalosporins work best?
rapidly proliferating bacteria
Second gen cephalosporins
cell wall synthesis inhibitors
competitively inhibit transpeptidase
Cephamycins
classified with 2nd gen cephalosporins
Third gen cephalosporins
cell wall synthesis inhibitors competitively inhibit transpeptidase
Ceftriaxone
3rd gen cephalosporin
Fourth gen cephalosporin
cell wall synthesis inhibitors; competitively inhibit transpeptidase
Cefepime
4th gen cephalosporin
Fifth gen cephalosporins
same as others
Carbapenems
cell wall synthesis inhibitors; competitively inhibit transpeptidase
Monobactams
binds and inhibits gram (-) specific sub-type of transpeptidase; cell wall synthesis inhibited
Glycopeptides
Bind D-alanyl-D-alanine terminus of cell wall precursor units, inhibiting transglycosylase and preventing cross-linking of peptidoglycans
damages cell wall
Vancomycin
glycopeptide
Lipoglycopeptides
same as glycopeptides, but also dimerize and embed their lipid structure into the bacterial cell membrane
get improved binding and increased potency
Oritavancin/telavancin
lipoglycopeptide; directly disrupt cell membrane; act faster
Beta lactamase inhibitors
Not actually antibiotics; inhibit beta lactamase
Tazobactam
beta lactamase inhibitor
Oxazolidinones
protein synthesis inhibitor
bind the P site on 50s ribosomal subunit, prevents initiation via prevention of fMET
Bacteriostatic
Macrolides
bind reversibly to 50s subunit preventing translocation of tRNA from A to P site–>halts protein synthesis
induce conformational change to inhibit transpeptidation
inhibit formation of 50s
bacteriostatic
Erythromycin, Clarithromycin, azithromycin, fidaxomicin
Macrolides
Ketolides
protein synthesis inhibitor
Streptogramins
inhibit protein synthesis
bind 50S
inhibits elongation and induces early termination
conformational change
Tetracyclines
inhibit protein synthesis
bind 30S and prevents aminoacyl tRNA from entering A site
prevents elongatin
Bacteriostatic
Glycycyclines
same as tetracyclines
Aminoglycosides
inhibit protein synthesis fix 50S and 30S to AUG inhibit translation promote early termination induce errors bactericidal
What do all aminoglycosides end in?
-mycin
Fluoroquinolones
inhibit transcription and replication by inhibiting bacterial topoisomerase II-gram (+) bacteria
block cell division by inhibiting DNA topoisomerase IV-Gram (-) bacteria
What do all fluoroquinolones end in?
-oxacin
Sulfonamides
acts as a competitive mimic of PABA to inhibit dihydropteroate synthase–>cannot make dihydrofolic acid from PABA
bacteriostatic
Benzylpyrimidines
comp inhibitor of dyhydrofolate reductase, which converts dihydrofolic acid to tetrahydrofolic acid
disrupts purine synthesis/bacterial DNA
Bactrim
Trimethoprim + Sulfamethoxazole
Polymixins
disrupt gram (-) membrane
act as cationic detergents
bind and inactive endotoxin
Bactericidal
What are all of the bacteriostatic drug classes?
Oxazolidinones Macrolides Tetracyclines Glycylcyclines Aminoglycosides Sulfonamides Polymixins
What is the primary abx for staph once MRSA is ruled out?
Penicillinase resistant penicillin poor gram (+) coverage
What do 3rd gen cephalosporins cover more of?
Gram (-), so less gram (+)
What does 4th gen cephalosporins also cover on top of 3rd?
P. aeruginosa
What drugs are bactericidal against strep?
Oxazolidinones
Streptogramins
