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Flashcards in Antimicrobials Deck (111):
1

What is the MOA of PCNs?

binds PBPs and block the transpeptidase cross-linking of peptidoglycan

Activate autolytic enzymes

2

What, generally, are the bacteria that PCNs are used to treat?

Gram positives:
-Strep
-Staph
-N Meningitidis

3

What is the major adverse reaction to PCNs?

Hypersensitivity rxns

4

How is resistance to PCNs conferred to bacteria?

Penicillinase in bacteria to cleave the beta-lactam ring

5

What are the three major beta lactamase inhibitors? (CAST)

-Clavulanic acid
-Sulbactam
-Tazobactam

6

What are the two major anti-pseudomonal PCNs?

Ticarcillin and piperacillin

7

What are the three major penicillinase resistant PCNs? What bacteria do these typically treat?

Oxacillin
Nafcillin
Dicloxacillin

"Naf for staph"

8

What are the two major penicillinase-sensitive abx?

Ampicillin
Amox

9

Which has more oral availability: amoxicillin or ampicillin?

AmOxicillin has more O-ral availability

10

What are the bacteria that ampicillin/amoxicillin are used to treat? (HELPSS)

Haemophilus
E.coli
Listeria
Proteus
Salmonella
Shigella

11

What is the general MOA of cephalosporins? Are these bactericidal or bacteriostatic?

Beta-lactam drugs that inhibit the cell wall synthesis, but are less susceptible to Penicillinases

bactericidal

12

What are the two first gen cephalosporins, and what are the three bacteria that they usually treat? (PEcK)

Cefazolin
Cephalexin

Proteus
Ecoli
Klebsiella

13

What are the three major third generation cephalosporins, and what are the 7 bacteria that they are used to treat? (HEN PEcKS)

Cefoxitin
Cefaclor
Cefuroxime

14

What is the general side effect of most cephalosporins?

Hypersensitivity rxn and it K deficiency

15

What other abx should never be combined with cephalosporins? Why?

aminoglycosides
Nephrotoxic

16

What is the only monobactam abx? MOA? Is this beta-lactam resistant?

Aztreonam
Resistant to beta lactamases
Prevents peptidoglycan cross-linking by binding to PCN-bind proteins

17

What is the abx that prevents peptidoglycan cross-linking by binding to PCN-bind proteins?

Aztreonam

18

What is the major side effect of aztreonam?

Occasional GI upset

19

What is the major bacterial type that aztreonam usually works against?

Gram negative rods ONLY

20

What two conditions are ceftriaxone used to treat?

Meningitis
Gonorrhea

21

What condition is ceftazidime used to treat?

Pseudomonas infx

22

What, generally, happens to the spectrum of activity as you progress in the generations of cephalosporins?

Increased

23

What is the MOA of carbapenems?

PCN-like--binds to PBPs and disrupts cell wall synthesis

24

Imipenem is always administered with what drug? Why?

Cilastatin to inhibit renal dehydropeptidase I

"The kill is lastin' with cilastatin"

25

What are the three general categories of bacteria that carbapenems are used against?

Gram positive cocci
Gram negative rods
Anaerobes

26

What are the side effects of carbapenems? (2)

Seizures at high plasma levels
Skin rash

27

What is the MOA of vancomycin?

Inhibits cell wall peptidoglycan formation by binding D-ala D-ala portion of cell wall precursors

28

What are the bacteria that vanco are used to treat?

Gram positive only

29

What are the side effects of vanco? ("NOT trouble free")

Nephrotoxic
Ototoxic
Thrombophlebitis
Red man syndrome

30

How can you prevent red man syndrome with Vanco?

Slow administration + antihistamines

31

What is the Mechanism of resistance against Vanco?

Amino-acid modification of D-ala D-ala

"Pay back 2 D-alas (dollars) for Vandalizing (Vanco)"

32

What are the two major 30s ribosome inhibitors? Which is bactericidal/bacteriostatic?

Aminoglycosides (bactericidal)
Tetracyclines (bacteriostatic)

33

What are the three 50s ribosome inhibitors? Which is bactericidal/bacteriostatic?

-Chloramphenicol and clindamycin (bacteriostatic)
-Erythromycin (macrolides) (bacteriostatic)
-Linezolid [variable]

34

What is the mnemonic for recalling the30s and 50s ribosome inhibitors?

"Buy AT 30, CCEL at 50"

35

MOA of aminoglycosides?

30s inhibitors--inhibit formation of initiation complex

36

MOA of macrolides?

50s inhibitor--inhibits the macro"slide"--blocks translocation

37

MOA of tetracyclines?

30s inhibitor--prevents attachment of tRNAs

38

MOA of linezolid?

50s inhibitor

39

MOA of chloramphenicol? Toxicity?

50s inhibitor-- blocks peptidyl transferase

Causes anemia and gray baby syndrome

40

MOA of clindamycin? What infections is this used to treat?

50s inhibitor--Blocks peptide transfer

Treats infections above the waist

41

What is the 30s subunit responsible for? 50s?

30s is small guy on the bottom that binds mRNA, 50s is the big guy on top that gets all the tRNAs

42

What is the suffix of aminoglycosides?

-micin or -mycin

43

What are the major toxicities of aminoglycosides? (NNOT)

Nephrotoxic
Neuromuscular blockade
Ototoxic
Teratogenic

44

What is the MOA of resistance against aminoglycosides?

Bacterial transferase enzymes inactivate the drug by acetylation

45

What is the suffix for tetracyclines?

-cycline

46

What is the MOA of resistance for tetracyclines?

Decreased uptake/increase efflux

47

What are the major toxicities of tetracyclines?

Discoloration of teeth and inhibition of bone growth in children

48

What is the MOA of resistance to macrolides?

Methylation of the 23s rRAN binding protein

49

What antibiotic causes gray baby syndrome, and why?

Chloramphenicol since infants lack UDP-glucuronyl transferase needed to breakdown it

50

What abx treats infections above the waist? Below?

Above - clindamycin
Below - metronidazole

51

What is the drug that is highly associated with causing C.diff?

Clindamycin

52

What is the MOA of sulfonamides? Use? Toxicity? MOA of resistance?

Inhibits folate synthesis
Gram positives and negatives
Hemolysis in G6PD, nephrotoxic
Altered bacterial DHP synthase)

53

What are the three macrolides?

Erythromycin
Clarithromycin
Azithromycin

"-thromycin" suffix

54

What is the MOA of trimethoprim? Toxicity?

Blocks bacterial dihydrofolate reductase
Megaloblastic anemia and leukopenia

55

What is the MOA of fluoroquinolones? Suffix? Clinical use? Toxicities (2)? MOA of resistance?

Inhibits DNA gyrase (topoisomerase II)
-floxacin
-Gram negative rods
-Tendonitis + prolonged QT
-Mutation in DNA gyrase

56

What is the MOA of metronidazole? Toxicity?

Free radical damage to DNA
Disulfiram-like effects

57

What are the infections (parasites and bacteria) that metronidazole is used to treat? (GET GAP on the metro)

Giardia
Entamoeba
Trich
Gardnerella
Anaerobes
Pylori

58

What are the four components of TB treatment (RIPE)?

Rifampin
Isoniazid
Pyrazinamide
Ethambutol

59

What is the drug of choice for prophylaxis against TB? MAC?

TB = isoniazid
MAC = Azithromycin + rifabutin

60

What is the MOA of isoniazid? Toxicities?

Decreases synthesis of mycolic acid
Neurotoxic and hepatotoxic

("INH Injures neurons and hepatocytes")

61

What is the MOA of rifamycins? What are the two drugs in this class?

Rifampin and rifabutin
Inhibits DNA dependent RNA pol

62

What are the major side effects of Rifampin?

Red/orange body fluids
"RifAMPin RAMPS up p450"

63

What are the "3 R's" of rifampin?

-RNA pol inhibitor
-Ramps up p450s
-Red/orange fluids

64

What major side effect can be avoided by switching from rifampin to rifabutin?

Avoid p450 induction--useful for AIDS pts

65

What is the MOA of pyrazinamide? Toxicities?

Unknown MOA
Hyperuricemia, hepatotoxic

66

What is the MOA of ethambutol? Toxicities?

-Decrease carb polymerization of mycobacterium walls
Optic neuropathy (red-green color blindness)

67

What is the TB drug that causes color blindness? Orange/red secretions?

Color blindness = ethambutol
Orange/red secretions = Rifampin

68

What is the antibiotic of choice for prophylaxis against: endocarditis?

PCNs

69

What is the antibiotic of choice for prophylaxis against: Gonorrhea?

Ceftriaxone

70

What is the antibiotic of choice for prophylaxis against: UTIs?

TMP-SMX

71

What is the antibiotic of choice for prophylaxis against: Meningococcal infx?

Cipro

72

What is the antibiotic of choice for prophylaxis against: GBS for pregnant women?

Ampicillin

73

What is the antibiotic of choice for prophylaxis against: Gonococcal/chlamydial infx in children?

Erythromycin

74

What is the antibiotic of choice for prophylaxis against: Post surgical S. Aureus infx?

Cefazolin

75

What is the antibiotic of choice for prophylaxis against: strep pharyngitis?

PCN

76

What is the antibiotic of choice for prophylaxis against: Syphilis

PCN

77

What is the antibiotic of choice for prophylaxis against: pneumocystis in AIDS pts? What is the CD4 count for this?

TMP-SMX
Less than 200

78

What is the antibiotic of choice for prophylaxis against: MAC in AIDS pts? What is the CD4 count for this?

Azithromycin
Less than 50

79

What is the antibiotic of choice for: VRE?

Linezolid

80

What is the antibiotic of choice for MRSA?

Vanco or daptomycin

81

What is the MOA of amp B?

Binds to ergosterol to make membrane leaky

"amphoTERicin TEArs holes"

82

What is the MOA of nystatin? Clinical use?

Binds to ergosterol to make membrane leaky

Oral candidiasis

83

What is the MOA of azoles? Toxicities?

Inhibits ergosterol synthesis
Testosterone synthesis inhibition

84

What is the MOA of flucytosine? Toxicities?

-Inhibits DNA and RNA biosynthesis by conversion of to 5-FU by cytosine deaminase
-Myelosuppression

85

What is the suffix of echinocandins? MOA? Toxicities?

-fungin
-Inhibits cell wall synthesis of beta-glucan
-Hepatotoxic

86

What is MOA of terbinafine? Use? Toxicity?

Inhibits squalene epoxidase
Dermatophytoses
Hepatotoxic

87

What is MOA of Griseofulvin? Use? Toxicity?

Inhibits microtubule assembly
Oral treatment of superficial fungal, infx
Increases Warfarin metabolism

88

What is the treatment for toxoplasmosis?

Pyrimethamine

89

What is the treatment for Trypanosoma brucei?

Suramin and melarsoprol

90

What is the MOA of Chloroquine? Use? Toxicity?

Blocks detoxification of heme into hemozoin
Plasmodial species BESIDES falciparum
Retinopathy

91

What are the two neuraminidase inhibitors against the flu?

Zanamivir
Osletamivir

92

What is the MOA of ribavirin? Use?

Inhibits synthesis of guanine by inhibits inosine monophosphate dehydrogenase

RSV

93

What is the MOA of acyclovir, famciclovir, and valacyclovir? Use?

Phosphorylated by thymidine kinase

HSV/VZV infx

94

What is the MOA of resistance against acyclovir, famciclovir, and valacyclovir?

Mutated thymidine kinase

95

What is the MOA of ganciclovir? Use

Guanosine analogue that inhibits DNA pol

CMV infections

96

What is the MOA of foscarnet? Use?

Viral DNA pol inhibitor that does NOT require activation by a kinase

Severe CMV infection--given IV

97

What is the MOA of resistance against Foscarnet?

Mutated DNA polymerase

98

What is the MOA of cidofovir? Use? Toxicity?

Inhibits DNA pol
CMV retinitis
Nephrotoxic

99

What is the common suffix for HIV protease inhibitors? Toxicities?

-"navir"
-Nephropathy

100

What is the MOA of zidovudine?

NRTI

101

What is the MOA of abacavir?

NRTI

102

What is the general MOA of NRTIs?

Competitively inhibit nucleotide binding to reserve transcriptase

103

What is the only NRTI that does not need to be phosphorylated prior to action?

Tenofovir is a nucleoTide

104

What are the three NNRTIs? MOAs?

-Efavirenz
-Nevirapine
-Delavirdine

Binds to reverse transcriptase at a non-active site

105

What is the MOA of raltegravir?

Inhibits HIV genome integration into host cell chromosome by inhibiting HIV integrase

106

What is the MOA of enfuvirtide?

BInds gp41, inhibiting viral entry

107

What is the MOA of Maraviroc?

binds CCR5 on T cell surface, inhibiting gp120

108

What is the use of interferon-alpha? (4)

Hep B and C
Kaposi sarcoma
hair cell leukemia
Condyloma acuminatum

109

What is the use of IFN-beta?

MS

110

What is the use of IFN-gamma?

Chronic granulomatous disease

111

What are the abx to avoid in pregnancy? (8, SAFe Children Take Really Good Care)

Sulfonamides
Aminoglycosides
Fluoroquinolones
Clarithromycin
Tetracyclines
Ribavirin
Griseofulvin
Chloramphenicol