Pharm antimicrobials 2 Flashcards Preview

ABBEY MSII U6 > Pharm antimicrobials 2 > Flashcards

Flashcards in Pharm antimicrobials 2 Deck (57):
1

vancomycin class

glycopeptide - cell wall synthesis inhibitor

2

vancomycin mechanism

binds rapidly and irreversibly to the D-alanyl-D-alanine group on the peptide side-chain of the membrane-bound precurosr; glycan chain extension, transpeptidation inhibited

3

vancomycin spectrum - why?

gram + only - molecule is HUUUUGGGGGEEEEE!!! can't get into gram -

4

vancomycin clinical uses

serious, multidrug-resistant organisms including MRSA, s epidermidis, enterococcus, clostridium difficile

5

vancomycin adverse effects

well tolerated in general but NOT trouble free (Nephrotoxicity, Ototoxicity, Thrombophlebitis and red man syndrome)
Red man driving a van down the intestine getting c diff

6

vancomycin administration

IV only - not absorbed orally

7

what is the advantage of vancomycin not being absorbed orally?

c difficile is in gut - it doesn't need to be absorbed to treat this

8

daptomycin class

cell wall TOXIN - lipopetide

9

daptomycin mechanism

penetrates gram + cell wall forming a channel for subsequent leakage of intracellular ions
-insertion into the gram + cell membrane causing depolarization and ultimate cell death

10

daptomycin spectrum

gram + cocci only - used for VRE and VRSA (vancomycin resistant organisms)

11

what is daptomycin not used for? why?

pneumonia because it avidly binds to and is inactivated by surfactant

12

daptomycin side effects

myopathy and rabdomyolysis,
also eosinophilic pneumonia

13

what are the lipoglycopeptides (analogs of vancomycin)

-vancins
dalbavancin, telavancin, oritavancin

14

-vancins mechanism

binds to same target as vancomycin (D-alanyl-D-alanine group on peptide side-chain of the membrane-bound precursor)--> cell wall precursor and inhibits transglycosylation

15

-vancins spectrum

similar to vancomycin (gram + only) but active against VRE and more anaerobe coverage

16

-vancins side effects

metallic taste, nausea, HA, nephrotoxicity, teratogenic (don't take if preggers)
also very very expensive

17

what is the half life of the -vancins? what is the longer half life due to?

telavancin - 7.5 hr
dalbavancin and oritavancin long (100+ hrs)
-due to lipophilic side chain that prolongs half life

18

are protein synthesis inhibitors bacteriocidal or bacteriostatic?

bacteriostatic EXCEPT aminoglycosides

19

30 S ribosomal subunit protein synthesis inhibitors

ATG = DNA = small
aminoglycosides, tetracyclines, glycylcyclines

20

50S ribosomal subunti protein synthesis inhibitors

COM = bigger and better!
clindamycin, oxazolidinones, macrolides

21

what are the aminoglycosides?

gentamicin, tobramycin, amikacin, streptomycin

22

aminoglycoside mechanism

bactericidal: irreversible inhibition of initiation complex through binding of the 30S subunti - can cause misreading of mRNA - also inhibits initiation

23

aminoglycoside spectrum

extremely effective against G- rods (esp enterics)
covers pseudomonas aeruginosa!!

24

what are aminoglycosides ineffective against? why?

anaerobes!! have O2 dependent uptake mechanism!!!

25

clinical use of aminoglycosides - what is it given with? why?

synergistic with cell-wall active agents for enterococcus infections (esp penicillins because they facilitate entry), cystic fibrosis (pseudomonas common infection)

26

aminoglycosides side effects

the MEAN GUY! (bacteriocidal)
-punch to the ear (ototoxicity)
-punch to the kidney (nephortoxicity)
-punch a pregnant woman (teratogen)
-knock them out (neuromuscular blockade)

27

which aminoglycoside is toxic and is typically only used topically for skin infections?

neomycin

28

which aminoglycoside has the broadest spectrum?

amikacin

29

what are the tetracyclines?

-cycline
doxycycline, minocycline, tetracycline

30

tetracycline mechanism

inhibits 30S ribsome - blocks access of tRNA anticodon to its codon

31

tetracycline spectrum

gram + (s. pneumoniae, MRSA), very effective againast intracellular pathogens (mycoplasma, chlamydia, legionella, rickettsia) and mycobacteria

32

what does tetracycline treat?

"the diseases soldiers get"
chlamydia, yickettsia, borrelia, m pneumonia, acne, tick borne illness

33

how is doxycycline eliminated?

fecally - can be used in patients with renal failure

34

tetracycline drug interaction

ORAL forms are chelated with divalent cations - don't take with milk (Ca), antacids (Ca, Mg), iron supplements because they can inhibit drug absorption in gut

35

tetracyclines side effects

think of soldier in night vision goggles
GI distress (need to take with water and standing up);, discoloration of teeth and inhibition of bone growth in children, photosensitivity and hyperpigmentation

36

mechanism of resistance to tetracyclines

efflux pump!

37

tigecycline class

glycylcycline

38

what is different about tigecycline (glycylcyclines)

9-glycl substitution enables it to overcomes two major types of resistance = efflux pumps and ribosomal protection

39

tigecycline spectrum

broad spectrum (covers tetracycline plus resistant organism) includes MRSA, VRE, enterobacteriaceae!!, anaerobes

40

what does tigecycline NOT have activity against?

pseudomonas

41

tigecycline side effects

GI - significant nausea, vomiting, and diarrhea - transaminitis, increased mortality --> used in situations when alternative agents are not suitable

42

what are the macrolides?

-THROMYCINs
azithromycin, clarithromycin, erythromycin

43

macrolides mechanism of action

inhibit protein synthesis by blocking translocation (macroSLIDES) bind to 50S subunit - bacteriostatic

44

macrolides spectrum

atypical pneumonias (mycoplasma, chlamydia, legionalla), gram + cocci (strep in patients allergic to penicillin), B pertussis

45

macrolides side effects

well tolerated usually - MACRO: GI Motility issues, Arrhythmia with prolonged QT, Colestatic hepatitis, Rash, eOsinophilia

46

macrolides drug interaction

increases serum concentration of theophylline, oral anticoagulants

47

which macrolide has the least GI distress?

erythromycin

48

clindamycin mechanism

binds to 50S subunit "A site" --> blocks peptide transfer (translocation) - bacteriostatic

49

clindamycin spectrum

treats anaerobic infections ABOVE the diaphragm (bacteroides spp, clostridium perfringens)
also effective against invasive group A strep

50

which drug is used ABOVE the diaphragm for anaerobic infections? BELOW?

above = clindamycin
below = metronidazole

51

clindamycin side effects

pseudomembranous colitis (C difficile overgrowth) because everything else was killed off, fever, diarrhea

52

what are the oxazolidinones?

-ZOLID
linezolid, tedizolid

53

oxazolidinones mechanism

inhibit protein synthesis by binding to 50S subunit and preventing formation of initiation complex

54

oxazolidinones spectrum

gram + including MRSA and VRE
NO gram - and poor anaerobe

55

oxazolidinones side effects

severe side effects if used for 2+ weeks - HEMATOLOGIC toxicity (bone marrow suppression with thrombocytopenia), peripheral neuropathy, SEROTONIN SYNDROME

56

what drug interaction does oxazolidinones have?

Serotonin syndrome if used with MAOis and SSRIs

57

how must tetracycline be taken?

with water and standing upright - cause pill esophagitis