Micro - Antimicrobial Drugs

Front 1

what were some of the earliest antimicrobial compounds?

Back 1

mercury and arsenic

Front 2

who discovered penicillin?

Back 2

alexander flemming in 1929

Front 3

when did penicillin come into use widespread?

Back 3

1940s

Front 4

when did sulfanilamide come into widespread use?

Back 4

1935

Front 5

where do many of our current antimicrobials isolates come from?

Back 5

streptomyces

actinomyces

Front 6

what is bacteriostatic?

Back 6

inhibits the growth of bacteria

Front 7

what is bacteriocidal?

Back 7

rapidly kill target organ

Front 8

what factors determine if a compound is bacteriocidal or bacteriostatic?

Back 8

susceptibility of target organism

if organism is actively growing

drug concentration

Front 9

what is MIC?

Back 9

minimum inhibitory concentration is the minimum concentration of a drug necessary to inhibit the growth of an organism

Front 10

what is a breakpoint?

Back 10

a breakpoint is a known MIC value that has been empirically determined for a given antimicrobial with a given pathogen in a given species

Front 11

what is MBC?

Back 11

minimum bactericidal concentration (MBC) is a better indication of the usefulness of bactericidal antimicrobial.

Front 12

what is spectrum?

Back 12

the spectrum of an antimicrobial agent is determined by how wide a variety of bacteria are affected by it

Front 13

what are the types of spectra?

Back 13

gram-positive spectrum (mostly affects grm +)

gram-negative spectrum (mostly affects grm-)

broad spectrum (affects both)

Front 14

what are the mechanisms by which antimicrobial resistance is genetically transfered?

Back 14

r-plasmids

transposons

integrons

bacteriophage infection

spontaneous

Front 15

what can enhance resistance development?

Back 15

agents that affect DNA synthesis , like trimethoprim.

Front 16

what are the primary antimicrobal agent MOAs?

Back 16

- inhibition of growth by analogues

- inhibition of cell wall synthesis

- cell membrane inhibitor

- inhibition of DNA synthesis

- inhibition of protein synthesis and assembly

- inhibition of 50s ribosomal subunit

Front 17

what is PABA?

Back 17

PABA is para aminobenzoic acid. is used to form folic acid, a necessary component for synthesis of nucleic acids.

Front 18

what is the general MOA of sulfonamides

Back 18

sulfonamides work by inhibiting growth by analogues

Front 19

how to sulfonamides work?

Back 19

sulfonamides are PABA analogues. they compete with PABA in the pathway for folic acid synthesis. in correct concentration, will inhibit folic acid pathway and prevent bacterial growth.

Front 20

where is sulfa drug used banned?

Back 20

most sulfa drugs are banned in food animals

Front 21

what is the MOA for sulfones?

Back 21

sulfones work by inhibiting growth by analogues

Front 22

what are two types of sulfones?

Back 22

dapsone (leprosy)

para aminosalicyclic acid (tb)

Front 23

what is trimethoprim?

Back 23

trimethoprim is often given along with sulfa drugs. it inhibits the folic acid pathway by aiting on dihydrofolate reductase.

Front 24

what drug is often given concurrently with sulfa drugs?

Back 24

sulfa drugs and trimethoprim are often given together

Front 25

what is a common sulfa-trimethoprim product?

Back 25

tribrissen is a common combination product

Front 26

which drugs work by inhibiting growth by analogues?

Back 26

sulfonamides (dapsone, parasminosalicyclic acid, tribrissen)

Front 27

which drug classes work by inhibiting cell wall synthesis?

Back 27

beta lactams

semisynthetic penicllins

cephalosporins

bacitracin

vancomycin

Front 28

what is the MOA of beta-lactams?

Back 28

beta-lactams contain a beta-lactam ring whcih binds to transpeptidases irreversibly. results in weakened bacterial walls and lysis of cell.

Front 29

what is the spectrum of penicillin?

Back 29

penicillin has a gram-positive spectrum

Front 30

what is the MOA of semisynthetic penicillins?

Back 30

inhibit cell wall synthesis

Front 31

how are beta lactams and semisynthetic penicillins different?

Back 31

semisynthetic penicillins can withstand stomach acid (PO administration), have increased solubility and longer activity. also are more active against gram negatives.

Front 32

what is the spectrum of semisynthetic penicillins?

Back 32

gram positive spectrum with some gram negative activity

Front 33

what are examples of semisynthetic penicillin drugs?

Back 33

amoxicillin

cloxacillin

Front 34

what makes cloxacillin unique?

Back 34

cloxacillin has the ability to resist breakdown by penicillinases.

Front 35

what are suicide molecules?

Back 35

suicide molecules like clavulanic acid adn taxobactam have a beta lactam ring but no antimicrobial action. they bind to penicillinase enzymes, protecting the beta lactam ring of penicillin/semisynthetic penicillins

Front 36

what is clavamox?

Back 36

clavamox is a combination production of amoxicillin and clavulonic acid.

- a "potentiated penicillin"

Front 37

what is the MOA of cephalosporins?

Back 37

inhibit cell wall synthesis

Front 38

what are examples of cephalosporins?

Back 38

ceftiofur

cefpodoxime

cefovecin

Front 39

how are cephalosporins advantageous to penicillin?

Back 39

- resist penicilinase to various degree

- less alergenic

- broad spectrum

Front 40

what are first generation cephalosporins?

Back 40

older cephalosporins are active against grm +, limited against grm -

Front 41

what are second generation cephalosporins?

Back 41

second generation are active against most gram positive and some gram negative

Front 42

what are third generation cephalosporins?

Back 42

third generation cephalosporins are active against gram NEGATIVE and some activity against positives

Front 43

what is an example of 1st generation cephalosporin?

Back 43

cephalothin

Front 44

what is an example of a 2nd generation cephalosporin?

Back 44

ceftoxin

Front 45

what is an example of a 3rd generation cephalosporin?

Back 45

ceftiofur, naxcel, excenel, cefovecin, cefpodoxime

Front 46

what is the MOA of bacitracin?

Back 46

inhibit cell wall synthesis

Front 47

what is bacitracin?

Back 47

bacitracin is a polypeptide isolated from bacillus subtilis

Front 48

how does bacitracin work?

Back 48

polypeptide interacts w/ bacterial cell membrane to prevent structural component transfer.

Front 49

what is the spectrum of bacitracin?

Back 49

bacitracin is gram negative spectrum

Front 50

how is bacitracin administered?

Back 50

bacitracin is given topically (toxic when given systemically)

Front 51

what is the MOA of vancomycin?

Back 51

inhibit cell wall synthesis

Front 52

what is the spectrum of vancomycin?

Back 52

gram positive spectrum

Front 53

which drug classes work by inhibiting cell wall synthesis?

Back 53

beta lactams

semisynthetic penicillins

cephalosporins

bacitracin

vancomycin

Front 54

why are cell membrane inhibitors potentially more toxic than those that inhibit cell wall synthesis?

Back 54

cell membrane inhibitors are potentially more toxic b/c they have the ability to affect host cells as well as bacterial cells

Front 55

what is the MOA of polymixin?

Back 55

cell membrane inhibitor

Front 56

how does polymixin work?

Back 56

polymix binds to the outer cell membrane surface and disrupts structure/function of phospholipid and lipopolysaccharide

Front 57

what is the spectrum of polymixin?

Back 57

gram negative spectrum

Front 58

how is polymixin administered?

Back 58

usually limited to topical application

Front 59

which polymixins are used in general practice

Back 59

only polymixin B and E are used, as the others (a, c, D) are highly toxic

Front 60

what is the MOA of polyenes?

Back 60

cell membrane inhibitor

Front 61

how to polyenes work?

Back 61

polyenes selectivly inhibit organisms with sterols in their cell membranes (fungi)

Front 62

what are commonly used polyenes?

Back 62

amphoteracin B

nystatin

Front 63

how is amphoteracin B administered?

Back 63

systemic, but has concern for nephrotoxicity

Front 64

how is nystatin administered?

Back 64

usually topically (eg panalog), as it is too toxic for systemic use

Front 65

how to 'Azoles' work?

Back 65

Azoles interfere with synthesis of ergosterol in fungal cell membrane.

Front 66

what are common Azoles?

Back 66

ketoconazole

miconazole

clotrimizole

Front 67

what drugs use cell membrane inhibitor as their MOA?

Back 67

polymixin

polyene

"Azoles"

Front 68

what is the MOA of quinolones?

Back 68

inhibitor of DNA synthesis

Front 69

how doe quinolones work?

Back 69

quinolones selectively block DNA synthesis by inhibiting DNA gyrase A.

Front 70

what are examples of quinolones?

Back 70

fluoroquinolones are currently in use

- enrofloxacin (baytril)

- danofloxacin

- norfloxacin

- ciprofloxicin

Front 71

which animals are fluoroquinolones permitted for use in?

Back 71

fluoroquinolones are used in pet animals, but have been banned in food animals since 2008

Front 72

what is the MOA of metronidazole?

Back 72

inhibitor of DNA synthesis

Front 73

what is metronidazole affective against?

Back 73

anaerobic bacteria

some protozoa

little/no effect against aerobes/facultative anaerobes

Front 74

what is the MOA of novobiocin?

Back 74

inhibitor of DNA synthesis

Front 75

what is the spectrum of novobiocin?

Back 75

gram positive spectrum

Front 76

how does novobiocin work?

Back 76

novobiocin inhibits DNA gyrase B to inhibit DNA synthesis.

Front 77

what is the spectrum of novobiocin and fluoroquinolone different?

Back 77

even though the MOA is the same for both (inhibitor of DNA synthesis), fluoroquinolones inhibit DNA gyrase A, while novobiocine inhibits DNA gyrase B.

Front 78

what drugs have inhibitor of DNA synthesis as their MOA?

Back 78

quinolones

metronidazole

novobiocin

Front 79

what is the MOA for rifampin?

Back 79

rifampin inhibits protein synthesis and assembly, specifically inhibiting transcription.

Front 80

how does rifampin work?

Back 80

rifampin selectively inhibits DNA dependent RNA polymerase in bacteria.

Front 81

what is the spectrum of rifampin?

Back 81

broad spectrum, especially effective against gram positive, mycobacteria, and rhodococcus equi

Front 82

what is the MOA of aminoglycosidic aminocyclitols?

Back 82

inhibitor of protein synthesis and assembly, specifically, inhibiting 30s ribosomal subunit

Front 83

what is an example of an aminoglycosidic aminocyclitol?

Back 83

streptomycin

neomycin

kanamycin

gentamicin

septinomycin

amikacin

tobramycin

Front 84

how are aminoglycosidic aminocyclitols administered?

Back 84

poor absorption from Gi, so must be given parenterally (potential for nephro/oto toxicity) or topically

Front 85

which animals cannot get aminoglycosidic aminocyclitols?

Back 85

food animals (due to residue persistence)

Front 86

what is the MOA of tetracycline?

Back 86

inhibitor of protein synthesis and assembly, specifically, inhibiting 30s ribosomal subunit

Front 87

how does tetracycline work?

Back 87

inhibits protein synthesis at 30s ribosomal subunit. bacteria accumulate large quantity of tetracycline in cell by energy-dependent transport system (euk. cell lacks this)

Front 88

what is the spectrum of tetracycline?

Back 88

broad spectrum

Front 89

how are tetracyclines administered

Back 89

parenterally

PO

Front 90

what are examples of tetracyclines?

Back 90

chlortetracycline

aureomycin

oxytetracycline

doxycycline

Front 91

what is the MOA of nitrofurans?

Back 91

inhibit protein synthesis by preferentially inhibiting synthesis of inducible enzyme needed for translation

Front 92

what is the spectrum for nitrofuran?

Back 92

wide spectrum of activity

Front 93

what drugs have inhibition of protein synthesis and assembly as their MOA?

Back 93

rifampin

aminoglycosidic aminocyclitols

tetracyclines

nitrofurans

chloramphenicol

florfenicol

erythromycin

lincomycin

long acting macrolide antimicrobials

griseofulvin

Front 94

what is the MOA of chloramphenicol?

Back 94

inhibitio of 50S ribosomal subunit

Front 95

how does chlorampehnicol work?

Back 95

bacteriostatic drug that binds to the 50S subunit and prevents tRNA from binding, inhibiting peptide bone formation.

Front 96

what animals is chloramphenicol permitted in?

Back 96

small aniamls

prohibited in food animals

percent of humans develop fatal toxic effects

Front 97

what is the MOA of florfenicol?

Back 97

structural analog of chloramphenicol.

bacteriostatic drug that binds to the 50S subunit and prevents tRNA from binding, inhibiting peptide bone formation.

Front 98

why would one use florfenicol instead of chloramphenicol?

Back 98

florfenicol is a structural analog of chloramphenicol without its side effects

Front 99

what drugs are considered macrolides?

Back 99

erythromycin

lincomycin

tilmicosin

clindamycin

Front 100

what is the MOA of erythromycin?

Back 100

inhibitor of the 50s ribosomal subunit

Front 101

what complications arise from giving erythromycin with lincomycin?

Back 101

the two drugs compete for the 50s ribosomal subunit spot

Front 102

how does erythromycin resistance develop?

Back 102

structural mutation of the 50s ribosomal subunit

Front 103

what is the MOA of lincomycin?

Back 103

inhibitor of the 50s ribosomal subunit

Front 104

what is the specturm of macrolide drugs?

Back 104

broad spectrum

Front 105

what is a common problem seen with macrolide use?

Back 105

elimination of normal flora

Front 106

what are long acting macrolide antimicrobials

Back 106

highly lipid soluble, distribute widely into tissues

inhibit the 50s ribosomal subunit

Front 107

examples of long acting macrolide antimicrobials?

Back 107

tilmicosin

draxxin

zactran

zuprevo

Front 108

what is the MOA of griseofulvin?

Back 108

inhibitor of protein assembly

Front 109

what is griseofulvin used to tx?

Back 109

ringworm

Front 110

what is the specific action of griseofulvin?

Back 110

inhibits mitosis in cells with chitin in their walls (fungi). prevents replication of actively growing fungi.