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Flashcards in anti-bacterials Deck (25):
1

what are two cefalosporins that have coverage against pseudomonas?

cetazidime (3rd gen)
cefepime (4th gen)

2

what gram negatives are covered by ceftriaxone?

HENS PEcK

H. influenza
Enterobacter aerogenes
Neisseria
Serratia

Proteus mirabilis
E. Coli
Klebsiella pneumonia

3

what type of antibiotic should not be combined with a loop diuretic due to the risk of ototoxicity?

aminoglycosides

gentamicin,
neomycin,
amikacin
tobramycin
streptomycin

remember "mean GNATS caNNOT kill anaerobes"

nephrotoxicity, neuromuscular blockade,
ototoxicity, teratogen

4

what antibiotic causes grey baby syndrome?

chloramphenicol - especially in premature infants because they lack liver UDP-glucoronyl transferase

5

what antibiotic is known for causing pseudomembranous colitis (C. diff) along with fever and diarrhea?

clindamycin - used for anaerobic aspiration infections such as bacteroids or clostridium perfringens

6

what type of antibiotic causes discoloration of teeth and inhibition of bone growth in children?

tetracyclines

ALSO PHOTOSENSITIVITY!!!!

7

what antibiotic cuases both dose dependent anemia and dose INDEPENDENT aplastic anemia as a potantial side effect?

chloramphenicol

8

Does TMP-SMX have activity against pseudomonas?

NO

but DOC for pneumocystis jiroveci, toxoplasma gondii, nocardia

9

what should be given to alcoholic with pneumonia?

clindamycin - covers bacteroides, prevotella, fusobacterium and peptospreptococcus - anaeobic oral flora

also covers strep pneumoniea

binds 50S ribosomal subunit thereby inhibiting protein sysnthesis

10

what drugs act on the 50s ribosmal subunit?

chloramphenicol, clindamycin, linezolid and macrolides (e.g. azythromycin)

11

where do macroles and clindamycin bind what is the mechanisms?

23S rRNA of the 50S subunit - block trranslocation of the ribosome on mRNA and inhibit protein synthesis

12

what is the resistance to macrolides?

bacterial aquisition of genetic material encoding methylation of the 23S sRNA inhibits macrolide binding

13

how is resistance to cephalosporins accomlished?

hydrolize the drug with cephalosporinases

14

what is the mechanism of doxy/tetracycline?

bind to 30S, block aminoacryl-tRNA binding to the A site of on the ribosome and inhibit ELONGATION

15

how is resistance to tetracyclines accomlished?

decreased uptake and increased transport out of the cell, chemical modification of the drug

16

what is the mechanism for fluoroqinolones (e.g. moxifloxacin)?

inhibit DNA replication by binding to and stabilizing DNA-DNA gyrase (topo II) complex

17

how is resistance to fluoroquinolones accomlished?

mutations that alter binding to DNA gyrase

18

what is the mechanisms for vancomycin?

inhibit cell wall synthesis by binding to the D-alanyl-D-alanine bacterial cell wall

19

how is resistance to vancomycin accomlished?

replacement of D-alanine with D-lactate

20

what drug must travel through porin channels in bacterial out membrane and require and energy dependent mechanism to cross the bacterial inner membrane before binding to the 30S subunit?

aminoglycosides

21

what is the mechanism of resistance for aminoglycosides?

decreased drug penetration or altered ribosomal binding sites

penecilins can increase aminoglycosides ability to penetrate in resistant bacteria

22

what is the mechanism of resistance for trimethoprim or suylfamethoxazole?

decreased permeability, modified enzyme binding

23

imipenem is given along with another drug. What is it and how does it work?

cilastatin

functions to prevent proximal renal tubular brush boarder hydrolysis of imipenem by dehydropeptidases (depeptidase) which prolongs imipenems antimicrobial effects in the URINE

24

pt has a postive FTA-ABS result and is gen what two drugs? One is for the infection. What is the purpose and mechanism of the second drug?

Penicillin G and probenecid

FTA-ABS = fluorescent treponemal antibody absoption assay aka positive for syphalis

probenecid is given to prevent renal tubular secretion of penecillin. It works by inhibiting organic anion transper (OAT) in the renal proximal tubule

probenecid also blocks the urate transporter in the same cells, which decreases reabsoption of uric acid

25

what tissue is tetracycline most likely to deposit in? Why?

Bone - forms stable compelexs with calcium

readily corsses placenta and can accumulate in fetal long bones => major reason for teratenicity

also accumulate in dentin of teeth causing yellow-grey staining and enamal hypoplasia

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