Lower extremity handbook

Question 1

PCNs

Answer 1

MOA - bind PBP on cell wall on gram +
more beta- lactamase in gram -, more PCN destroyed

resistance- beta-lactamase hydrolyze PCN
altered PBP site
altered cell membrane gram -

spectrum- all cover enterococci

Question 2

natural PCNs

Answer 2

spectrum- strep, staph
anaerobes (NOT bacteroides)
enterococci
gonococci

Question 3

aminopenicillin

Answer 3

strep, staph
gram - E coli, proteus, shigella, salmonella
enterococci

Question 4

semi-synthetic PCNs

Answer 4

staph, strep

Question 5

PCN use

Answer 5

cellulitis with strep

OM with strep infection

septic arthritis- gonococcus

clostridial elluslitis/gas gangrene

Question 6

PCN V, G

Answer 6

oral, potassium salt

dose 250 to 500 mg qid

minor dose adjustment for renal function

higher serum level if without food

Question 7

ampicillin (Unasyn) spectrum

Answer 7

aminopenicillin

IM, IV
oral- not well absorbed in GI

spectrum- better gram - than reg PCN
h influenza, Proteus, salmonella, shigella
some E coli

strep
NO (little ) staph- PCNase resistant

better enterococci (bacteriostatic, aminoglycoside to kill)

Question 8

ampicillin rxn, dose use

Answer 8

Rxn- rash esp with EBV, CMV
diarrhea

dose
250-500 mg QID PO
empty stomach

2g q6h IV
probenecid increase serum level (PCNs)

use- limited for wounds, susceptible bugs found in mixed infections

use for gram - wound
enterococci infection

Question 9

amoxicillin

Answer 9

aminopenicillin
hydroxy group, better oral absorption

dose 250 to 500 mg TID PO
food has little effect
probenecid prolong

rxn- rash
diarrhea

use- gram - wound
enterococci infection

Question 10

nafcillin

Answer 10

semi-synthetic PCN, resist PCNase

better staph than methicillin

spectrum- staph, strep
NO MRSA
NO enterococci
no gram - rod

rxn- neutropenia

dose
1-2 g q6h IV IM
probenecid increase serum level

no renal adjustment needed, adjust hepatic failure

*parenteral PCN for staph infection

Question 11

cloxacillin/ dicloxacillin

Answer 11

isoxazolyl PCN (semi synthethic PCN)

oral

spectrum- staph, strep
NO MRSA
NO enterococci
no gram - rod

dose250to 500 QID PO
empty stomach
little change dose for renal insuff
probenecid increase serum levl

oral PCN of choice for staph infection

Question 12

cabenicillin

Answer 12

extended spectrum PCN

spectrum- cover pseudomonas but not drug of choice (now use quinolones)

now UTI use only

Question 13

ticarcillin

Answer 13

extended spectrum PCN

spectrum
PSEUDOMONAS
proteus, enterobacter
less strep, enterococci 
anaerobes 
NO staph

rxn high Na 120mg/g > hypokalemia, hypernatremia
bleeding- platlet dysfunction

3g q6h
probenecid increase serum level
renal clearance highly affect dose

use w/aminoglycoside for gram - infection
“back shelf”- safer drugs trump

Question 14

piperacillin (Pipracil)

Answer 14

extended spectrum PCN

good pseudomonas
strep
NO staph

dose 3-4g q6h

use w/aminoglycoside for severe infection
single rx now replace

Question 15

beta-lactamase inhibitor combos

Answer 15

not effective against pseudomonas, serratie, enterobacter, morganella, citrobacter

NOT use alone for pseudomonas

only use alone if parent PCN can be used alone for spectrum

Question 16

ticarcillin/calvulonic acid (Timentin)

Answer 16

3 g Ticaracillin, 100 mg calvulonic acid

spectrum- staph, strep
NO MRSA
gram -, anaerobes (bacteriodes)

NOTfor pseudomonas

adverse- Na loading

3.1 g q6h IV
decrease w/renal failure

use- DM infection
animal bite wound
anaerobe infection, polymicrobial

now replaced by Zosyn (piperacillin/tazobactam)

Question 17

amoxicillin/clavulonic acid (Augmentin)

Answer 17

250, 500, 875 mg tabs
125 mg clauvulonic acid in ea
DO NOT double up tabs

Augmentin XR 1 gm amoxicillin, respiratory infection ONLY

staph, strep
NO MRSA
enterocci
gram -
anaerobes

500-875 BID PO
no efffect w/food

SE diarrhea

use- DM infection
animal/human bite (empiric)
not for monomicrobial infection

Question 18

ampicillin/sulbactam (Unasyn)

Answer 18

2:1 ratio

3g IV q6h