penicillins Flashcards
B lactam family
penicillin
cephalosporins
carbapenem
monobactams
chemical structure of penicillin
5 membered A ring with S inside the ring
chem structure of cephalosporins
6 membered A ring with S inside the ring
chem structure of carbapenem
5 membered A ring with S OUTSIDE of ring
chem structure of monobactam
no A ring
mechanism of b lactams
active when?
inhibit peptide cross linking of bacteria cell wall
active in ACTIVELY proliferating bacteria– no effect on NON dividing bacteria
what agents can antagonize bacterial cell wall inhibitors
bacteriostatic agents
B lactams are bactericidal, they only work on actively proliferating bacteria
penicillin mech of action
inhibit transpeptidation
bind to PBP (which are transpeptidase enzymes needed that remove remaining D alanine to cross link peptidoglycan)
standard penicillins (3)
penicillin G
penicillin V
depot penicillins
antistaphylococcal penicillins (3)
nafcillin
oxacillin
diclosacillin
methicillin
extended spectrum penicillins (2)
amoxicillin
ampicillin
anti pseudomonal penicillin (1)
piperacillin
synergistic effect of penicillin with ____
penicillin and aminoglycosides
b lactamase inhibitors (3)
clavulanic acid
sulbactam
tazobactam
routes of standard penicillins
G- IV
V- oral
dept- IM
targets of penicillin G
gram + that dont have a b lactamase - streps (pyogenes, agalactiae, pneumo, viridans) - enterococci - bacillus - Clostrisdium (perfingens, tetani) - Listeria - Actinomyces* meningococci (gram -) spirochetes - treponema pallidum - leptospirae
penicillin G drug of choice for
gas gangrene (c. perfingens)
Menigitis (neisseria)
syphillis (treponema)
penicillinG and Gentamycin( aminoglycoside) tx
enterococci
penicillin G route
IV
penicillin V route
tx
PO- [ due to acid stability] tx orpharyngeal infections - pharyngitis- strep throat - tonsillitis - scarlet fever [RF] (s pyogenes) URT - otitis media* - sinusitis
which penicillin best for syph
Benzanthine Penicillin G ( bicillin LA)– long lasting
routes for antistaphylococcal pncn
nafcillin - IV IM
oxacillin - IV IM
diclosacillin- PO
methicillin - not used anymore
spectrum for antistaphylococcal pncn
Staph producing b lactamases
route for extended [broad] spectrum pncn
amoxicillin- oral
ampicillin- iv
spectrum for extended spectrum
same as penicillin G (gram + without b lactamases, meningococci, spirochetes)
+ MORE GRAM -
- e coli
- proteus
- salmonella
- shigella
- Hib (r)
- moraxella (r)
amoxicillin drug of choice for
(most prescribed penicillin)
- prophylaxis for BACTERIAL endocarditis [ like dental procedures]
- tx tonsillitis and pharyngitis s. pyogenes
- otitis media
ampicillin drug of choice for
- listeria monocytogenes**
- over amoxicillin for GI ( salmonella and shigella– bc 50% absorbed and 50% left)
anti pseudomonal and route
piperacillin IV IM
(zosyn )- has b lactamase inhibitor
piperacillin drug of choice for
pseudomonal infections
piperacillin spectrum
BROADEST spectrum penicillin
gram + without b lactamases, meningococci, spirochetes)
+ MORE GRAM - e coli - proteus- salmonella- shigella- Hib -moraxella
+ MORE GRAM -
- pseudomonas
- klebsiella
- serratia
- bacteroides
- enterobacter
- citrobacter
resistance for penicillins
intrinsic- chromosomal b lactamase
acquired- plasmid: B lactamase (MOST commmon)
what is the basis of development of MRSA
altered target site— structural changes in PBP — lowe affinity of antibiotics
pharmakokinetics of penicillins
- oral
- food
- BBB
- excretion
oral: penicillin V, dicloxacillin, amoxicillin, need to be given one hour before meals
dont cross BBB except during inflammation ( G V)
excreted by the kidney
which drug blocks penicillin excretion
probenecid-
which penicillins ARENT excreted by kidney
meaning?:
Nafcillin- BILE
oxacillin- bile and kidney
dicloxacillin- bile and kidney
- means that they can be given in pts with REDUCED renal function !!!!
adverse effect of pncn
allergic hypersensitivity reaction
- if you are allergic to pncn you have cross sensitivity with other b lactams EXCEPT monobactam ) bc it doesnt have A ring )
pncn with b lactamase inhibitors
augmentin
unasyn
zosyn
augmentin: amoxicillin and clavulonic acid
unasyn: ampicillin and sulbactam
zosyn: piperacillin and tazobactam
tx penicillinase + organisms
- e coli
- hib
- moraxella
use of clavulonic acid
sulfabactam
tazobactam
b lactamase inhibitors- they have the ring but no actual antibiotic activity—
but they protect the penicillins from degradation
use for nafcillin oxacillin and dicloxacillin
for penicillin resistant staph
[- skin abcesses
- endocarditis
- osteomyelitis ]
