Aminoglycosides And Cell Wall Ab

Front 1

Examples of aminoglycosides

Back 1

streptomycin
gentamycin
tobramycin
amikacin
neomycin
kanamycin

Front 2

Examples of macrolide AB

Back 2

erythromycin
clarithromycin
azithromycin

Front 3

Examples of streptogramins

Back 3

quinupristin
dalfopristin

Front 4

Examples of tetracyclines

Back 4

tetracycline
chlortetracycline
oxytetracycline
demeclocycline
Methacycline
Doxycycline
minocycline

Front 5

What is the basic mech behind broad spectrum abx

Back 5

inhibits bacterial protein synth

Front 6

MOA of aminoglycosides
cidal or static?

Back 6

Biinds 30s ribosomal subunit, irreversibly interfering with protein synth
cidal (w killing being [] dependent)
also has post-abx effect, w antibacterial activity persisting beyond time that measurable amt of drug is present

Front 7

What type of bacteria are aminoglycosides effective against?

Back 7

gram - enteric bacteria , esp in bacteremia and sepsis

Front 8

What can be combined with aminoglycosides to treat endocarditis? TB?

Back 8

vancomycin or penicillin for both

Front 9

MOR against aminoglycosides

Back 9

inactivation of aminoglycosides by plasmid encodied transferase enzymes
impaired entry of aminoglycoside into cell
modification of ribosomal binding site
**transferase mediated R is main type**

Front 10

Absorption of aminoglycosidES
distribution

Back 10

poor from GI tract, give IM
highly polar that don't enter cells readily, largely excluded from CNS and eye
usually only high levels are found in UTI

Front 11

Uses of SM?

Back 11

2nd line agent for TB tx, used in combo with other agents to prevent R

Front 12

What are tobramycin a nd gentamycin used to treat?
which is cheaper?

Back 12

sepsis and pneumonia from gram - bacteria that are R to other drugs
used in combo with B-lactam (penicillin)
burns, wounds, skin lesions

gentamycin

Front 13

what s amikacin used to treat?

Back 13

resistant micro-organisms
it si R to many enzymes that inactivate gentamycin and tobramycin

Front 14

what are neomycin adn kanamycin used to treat?

Back 14

only topical (injected in to joints/pleural cavity,) and/or oral use (to cleanse large bowel for elective colorectal surgery)

Front 15

Adverse effects of aminoglycosides

Back 15

all are nephrotoxic
ototoxicity when used for >5 days --> auditory and vestibular damage (ototoxicity is irreversible)

Front 16

which aminglycosides are the most nephrotoxic?
how is it made worse?
is it reversible?

Back 16

neomycin
tobramycin
gentamycin

concurrent use of loop diuretics

yes

Front 17

Which aminoglycosides are the most ototoxic?

Back 17

for hearing:
neomycin
kanamycin
amikacin

for vestibular:
SM
gentamycin

Front 18

MOA chloramphenicol

Back 18

binds to 50S ribosomal subunit, interferes with protein synth

Front 19

spectrum of chloramphenicol?

Back 19

aerobic and anaerobic gram +/- bacteria (esp gram -, in bacteremia and sepsis)

Front 20

what is chloramphenicol commonly combined with?

Back 20

vanco
penicillin
(used to treat endocarditis and tb)

Front 21

MOR to chloramphenicol?

Back 21

production of chloramphenicol acetyltransferase (plasmid encoded enzzyme that inactivats the drug)

Front 22

Pharmacokinetics of chloramphenicol

Back 22

rapidly and completely absorbed after oral admin
widely distributed to all tissues and body fluids (incl CNS and CSF)
penetrates cell membrane readily

Front 23

How is chloramphenicol cleared primarily from body?

Back 23

liver

Front 24

Uses of chloramphenicol

Back 24

don't use systemically, bad side effecs and widespread R
Rickettsial infections in children <8 yo
alt to B-lactam for bacterial meningitis caused by pen-R strianst of pneumococcus and meningococcus
eye infectiosn (penetrates ocular tissue and is broad-specrum)

Front 25

Adverse rxns to chloramphenicol

Back 25

GI probs (N/V/diarrhea in adults, not kids, candidiasis)
bone marrow probs (aplastic anemia and RBC suppression)
toxicity for neonates (lack liver enzymes to detox drug)
intearctions with other drugs (inhbiits liver enzymes)

Front 26

what can happen to infants taking chloramphenicol

Back 26

gray baby syndrome w vomiting, flaccidity, hypothermia, gray color, shock, colllapse

Front 27

what drug interactinos are there w chloramphenicol

Back 27

bacteriostatic protein synth inhibitors
antagonizes cidal drugs (like penicillin and aminoglycosides)

Front 28

MOA of macrolides

Back 28

bind 50S ribosomal subunit

Front 29

spectrum of macrolides

Back 29

gram +
strep, staph, pneumococci, corynebacteria

Front 30

MOR of macrolides

Back 30

reduced perm of cell membrane or active efflux
production of esterases that hydrolyze macrolides
modifications of ribosomal binding sites by chromosomal mutation or methylation

Front 31

Pharmacokinetics of macrolides

Back 31

widely distributed, except brain and CSF
traverse placenta and reach fetus
not a prob in pts with renal probs

Front 32

What happens to macrolides in stomach

Back 32

gets destroyed by acid, so must have enteric coating

Front 33

which macrolide has longest t 1/2? how long/

Back 33

azithromycin
3 days

Front 34

Clinical uses of macrolides

Back 34

corynebacterial infections
resp, neonatal, ocular, and genital chlamydial infections
community acquired pneumonia

Front 35

adverse effects to macrolides

Back 35

GI (anorexia, N/V/D, stim of gut motility)
liver toxicity --> acute cholestatic hepatitsi (hypersens rxn?)
Drug interactiosn

Front 36

which macrolide drugs cause drug interactions? whihc ones don;t?

Back 36

erythromycina nd clarithromycin metabolites inhbiit p450 increasesing serum [] of teophylline, oral anticoags, cyclosporine, methyprednisolone
azithromycin doesn't affecct p450

Front 37

Antimicrobial activity of linezolid?
static or cidal?

Back 37

gram + aerobes and anaerobic cocci
gram + rods (corynebacteria and listeria)
MT
generally static except against streptococci (cidal)

Front 38

MOA linezolid

Back 38

inhibits protein synth by preveting formation of ribosome complex that initiates protein synth

Front 39

MOR of linezolid

Back 39

unique binding site on 23S ribosomal RNA of 50S subunit
so, no x-R with other drug classes
R from mutation of linezolid binding site on 23S ribosomal RNA

Front 40

pharmacokinetics of linezolid

Back 40

100% bioavailable after oral admin
doesn't affect p450

Front 41

Clinical uses of linezolid

Back 41

VRE
nosocomial pneumoania
strep/MRSA skin infections
reserved for tx of infections caused by MDR gram + bacteria

Front 42

Adverse rxs to linezolid

Back 42

GI, HA, rash
thrombocytopenia (esp if >2wks)
neutropenia
weak MAOI (watch out w tyramine)
peripheral and optic neuropathy

Front 43

What is quniupristin-dalfoprisitn?

Back 43

combo of 2 streptogramins
cidal for most organisms
gram +, MDR orgs and MRSA

Front 44

R to streptogramins

Back 44

modification of ribosomal binding site of quinupristin
inactivation of dalfopristin
drug efflux

Front 45

are dose-adjustments needed for streptogramins in pts with renal probs

Back 45

no

Front 46

adverse rxns to streptogramins

Back 46

painat infusion site
arthralgia-myalgia
inhibit CYP3A4

Front 47

MOA of tetracyclines

Back 47

binds 30S ribosomal subunit, interferign with protein synth

Front 48

spectrum of tetracyclines

Back 48

gram +,-
anaerobes
rickettsiae
chlamydiae
mycoplasma
protozoa

Front 49

MOR against tetracycline

Back 49

decreased intracellular accumulation d/t impaired influx or increased efflux by active transport protein pump
ribosome protection d/t production of proteins that interfere with tetracycline ribosome interactions
enzymatic inactivations of tetracyclines

Front 50

which tetracycline has best oral bioavailabity?
what affects oral bio?

Back 50

doxy and minocycline
food decreases absorption (Ca, Mg, Fe, Al, dairy, antacids, and high pH)

Front 51

distribution of tetracyclines

Back 51

everywhere but CSF
tetra x placenta and enters breast milk

Front 52

which tetracycline is best to use in renal failure

Back 52

doxy

Front 53

dosing of oral doxy?

Back 53

1x day, absorption not affected by food

Front 54

adverse rxns to tetracyclines

Back 54

GI
binds Ca so affects bone and tooth formation
deposited in fetal teeth
impar hepatic fxn (esp during preg)
RTA, N retention
DVT if given IV, IM is painful local irritiation
UV sensitization
vestibular rxns