Antibiotics IIb Flashcards Preview

Year 2 Pharmacology > Antibiotics IIb > Flashcards

Flashcards in Antibiotics IIb Deck (33):
1

which antibiotic is highly associated with c. diff infection?

clindamycin

2

does chloramphenicol exert a bacteriostatic or bacteriocidal effect?

bacteriostatic

3

chloramphenicol is mainly used for what infections?

typhus
rocky mountain spotted fever

4

what is the MOA of chloramphenical?

binds to 50S subunit and prevents transpeptidation or peptidyl bond formation

5

what are the key adverse effects of chloramphenicol?

blood - suppression of RBC production

gray baby syndrome

6

what is gray baby syndrome? what causes it?

infants lack glucuronic acid conjugation

chloramphenicol

7

linezolid is effective against what type of bacteria?

gram positive

8

what antibiotic is effective against organisms resistant to penicillin, methicillin, and vancomycin? why?

linezolid

check recording

9

what is the MOA of linezolid?

binds to P site of 50S subunit and inhibits formation of ribosomal-fMet-tRNA complex (step 1)

10

what is the key adverse effect of linezolid?

blood - myelosuppression

11

what is the only protein synthesis inhibitor agent that is not broad spectrum?

clindamycin

12

why dont the sulfonamides affect mammalian cells?

they depend upon exogenous folate and do not synthesize folate

13

what is the MOA of the sulfonamides?

structural similarity to PABA - precursor to dihydrofolic acid

compete with PABA for dihydropterase synthase and block dihydrofolate synthesis and thus DNA synthesis

14

what is the key adverse effect of sulfonamides?

skin

hypersensitivity
photosensitivity
steven johnson syndrome

15

trimethoprim agents target what type of bacteria?

gram negative

16

what is the MOA of trimethoprim?

inhibitor of BACTERIAL DHFR - impaired DNA synthesis

17

what is the key adverse effect of trimethoprim?

blood

bone marrow suppression
megaloblastic anemia
leukopenia

18

what combination of DNA synthesis inhibitor agents is used to treat UTIs and prostatitis?

trimethoprim-sulfamethoxazole (TMP-SMX)

19

what is the MOA of TMP-SMX?

synergistic

20

ciprofloxacin and levofloxacin are what class of abx?

fluoroquinolones - DNA synthesis inhibitor

21

what is the MOA of fluoroquinolones?

disrupt winding of DNA and separation of DNA strands during transcription and replication

specifically inhibit topoisomerase II (DNA gyrase) and topoisomerase IV

22

what are the key adverse effects of fluoroquinolones (eg cipro)?

GI - nausea, vomiting, diarrhea

drug nutrient interactions - bind divalent cations, prevent absorption (calcium)

CV - QT prolongation

23

what are the targets of group 2 fluoroquinolones? what are the group 2 fluoroquinolones?

1. work well against gram negatives
2. some activity against gram positive

ciprofloxacin, levofloxacin, ofloxacin

24

metronidazole is active against bacteria and what other type of organism?

protozoa

25

metronidazole is effective against bacteria with what property?

anaerobic

26

what is the MOA of metronidazole?

prodrug - undergoes activation inside organism - reaction metabolites bind to DNA and cause damage

27

what are the key adverse effects of metronidazole?

GI
metabolism - disulfiram effect (avoid alcohol)

28

what is the MOA of daptomycin? what is required for this action?

causes depolarization of membrane - bacteriocidal

calcium dependent

29

what are the key adverse effects of daptomycin?

musculoskeletal system - myopathy

30

what type of antibiotic is polymyxin B?

detergent

31

polymyxin B is typically combined with what other drug? for what purpose?

bacitracin

topical

32

why is polymyxin B effective?

sticks to LPS (gram negative)

33

what is the MOA of polymyxin B?

binds to phospholipids in the cell membrane and disrupts structure (punches holes), specifically LPS

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