Exam 2 Flashcards
toxicities of sulfa drugs
aplastic anemia hypersensitivity Stevens Johnson Syndrome photosensitivity kernicterus
contraindications for sulfa drugs
near term pregnant women
nursing, premature, or jaundice infants
< 2 months old
sulfasalazine MOA and use
prodrug, metabolite mesalamine is anti-inflammatory
used for Crohn’s, ulcerative colitis, RA
1st DOC for UTI
Bactrim
MOA for Bactrim
sulfamethoxazole: compete with PABA in bacterial cell folic acid synthesis
trimethoprim: prevents conversion of DHF to THF for purine synthesis
spectrum for Bactrim
G+ and G-
relationship of trimethoprim and sulfamethoxazole
synergistic
use of silver sulfaziadine
topical for burns
Bactrim: cidal or static?
bacteriostatic, except it is bactericidal in the urinary tract
MOA of daptomycin
rapidly depolarizes membrane which eventually leads to cell death
spectrum of daptomycin
cidal, G+ (MRSA, MSSA)
route of administration for daptomycin
IV
MOA of mupirocin
inhibit tRNA synthetase of isoleucine, inhibits protein and RNA synthesis
route of administration for mupirocin
topical
skin: impetigo
nares: MRSA
spectrum of mupirocin
G+ and G-, bacteriostatic at low concentrations and bactericidal at high concentrations
MOA for polymixin B and E
binds to lipid A, increases permeability which results in loss of metabolites
spectrum of polymixin B and E
G-
route of administration for polymixin B and E
topical (nephrotoxic), used in combination with neomycin and bacitracin
1st gen cephalosporins
Cephalexin (oral), Cefazolin (IV/IM)
2nd gen cephalosporins
Cefuroxime (IV/IM), Cefprozil (oral), Cefaclor (oral)
3rd gen cephalosporins
Ceftriaxone, Cefixime (oral), Ceftazidime, Cefotaxime
-all others are IV/IM
4th gen cephalosporins
Cefepime (IV)
“5th” gen cephalosporins
Ceftaroline (IV)
DOC for surgery prophylaxis
Cefazolin (IV/IM)
DOC for N. Gonnorhea
Ceftriaxone (IV/IM)
What advantage does cephalosporins have over penicillins?
They have a 7 methyl group that makes them more resistant to penicillinase
MOA of cephalosporins
ICWS, b-lactam
spectrum for 1st gen cephalosporins
good G+, relatively moderate G-, MSSA
spectrum for 2nd gen cephalosporins
lower G+, more G- (E.coli, Klebsiella, Proteus)
3rd gen cephalosporin for Pseudomoas
ceftazidime + aminnoglycoside
spectrum for 3rd gen cephalosporins
less G+, pseduomonas, enterobacteriaceae
contraindications for 3rd gen cephalosporins
neonates due to bilirubin displacement
spectrum for 4th gen cephalosporins
comparable to 3rd gen with more G+ coverage + MSSA
spectrum for 5th gen cephalosporins
G+ and G-, MRSA, VRSA, CABP
NO PSEUDOMONAS ACTIVITY
DOC for E. Coli, Proteus, Klebsiella
1st or 2nd gen cephalosporins
DOC for late stage Borrelia Burgdorferi
Ceftriaxone
Toxicity of cephalosporins
superinfection diarrhea disulfram like reaction allergy (10% cross reaction with pen allergy) dose dependent renal tubular necrosis
MOA for Aztreonam
a b-lactam, ICWS, PBP, cidal
spectrum for aztreonam
G- only
route of administration for azetronam
parenteral
list carbapenems
imipenem (+ cilastatin), meropenem, ertapenem
route for imipenem and meropenem
IV
spectrum for impienem and meropenem
G+, G-, Anaerobes
BROAD SPECTRUM
toxicity of imipenem
can cause seizures, so patients with past history, impaired kidney function, CNS deficits should avoid
DOC for B-lactam producing enterobacter infection
imipenem or meropenem
spectrum for ertapenem
G+, G-, anaerobic, particular enterobacteriaceae
do not use for pseudomonas
route for ertapenem
IV or IM
MOA for vancomycin
cidal, ICWS, prevents transpeptidation of chain by binding to the D-alanine site
Resistance MOA for vancomycin
bacteria mutates d-ala to d-lactate so drug cannot bind
Adverse affects of vancomycin
ototoxicity
nephrotoxicity
red man syndrome (not a hypersensitivity)
route for vancomycin
ORAL
spectrum for vancomycin
G+, MRSA, G+ infections not responding to penicillin
DOC for C. Diff
Vancomycin
MOA of fosfomycin
inhibits cell wall synthesis at one of the first steps in the peptidoglycan pathway
spectrum of fosfomycin
G+ and G-
MOA of bacitracin
interferes with the final dephosphorylation step, NAG-NAM cannot get transported across the membrane
route for bacitracin
parenteral (rarely nephrotoxic) and topical
spectrum for bacitracin
mostly G+
MOA for fluoroquinolones
bactericidal
Inhibits DNA gyrase and Topo IV
Spectrum for fluoroquinolones
Mostly Gram - aerobes, some G+
Moxi and Gemi also cover anaerobes
Ciprofloxacin
UTIs, systemic tx, anthrax prophylaxis, Pseudomonas
Ofloxacin
Prostatitis, some systemic, some STDs (no syphilis), TB
Levofloxacin
CAP
Moxifloxacin
Anaerobes, Pen. resistant Strep pneumoniae
Gatifloxacin
ocular application only
Gemifloxacin
Anaerobes, Pen. resistant Strep pneumoniae, CAP
route of administration for fluoroquinolones
ORAL
patient education on fluoroquinolones
must stop taking supplements during course of treatment
adverse effects of fluoroquinolones
GI disturbances long QT interval photosensitivity cartilage erosion tendon rupture
FQ contraindications
children under 18 and pregnant women
MOA for metronidazole
prodrug, interacts with ferredoxin, metabolite up taken by bacterial cell, bactericidal
spectrum of metronidazole
Anaerobes: G+ and G-
indication for metronidazole use
bacterial vaginosis, endocarditis, C.diff, RTI, abdominal infections, h. pylori therapy
route of administration for metronidazole
oral, IV, topical
adverse reactions of metronidazole
disulfram like reaction, disgeusia (metallic taste)
most common UTI pathogen
E. coli
second most common UTI pathogen
staph. saprophyticus
most important property of UTI drugs
they are renally excreted
MOA for Nitrofurantoin
bactericidal, damages bacterial DNA, a prodrug
Resistance to Nitrofurantoin
Proteus and Pseudomonas organisms
route of administration for nitrofurantoin
oral
Nitrofurantoin should not be used if creatinine clearance is less than what?
50 mL/min
toxicity of nitrofurantoin
pulmonary fibrosis in elderly, hepatocellular damage, hemolytic anemia
contraindications for nitrofurantoin
pregnancy, < 1 month old, reduced renal function
MOA for methenamine
prodrug, metabolizes into ammonia and formaldehyde, formaldehyde is what kills the bacteria
spectrum for methenamine
nearly all bacteria are sensitive, but those that increase the pH of the urine inhibit the release of formaldehyde (Proteus species)
contraindications for methenamine
hepatic insufficiency, too much ammonia build up
renal insufficiency, low urinary output
30 s subunit
tetracyclines and aminoglycosides
aminoglycosides: cidal or static?
cidal
Name the 3 macrolides
Azithromycin, oral/IV
Clarithromycin, oral
Erythromycin, oral/IV
MOA of macrolides
binds to the 50s subunit on the ribosome, bacteriostatic
DOC for chlamydia
Azithromycin
**if pregnant must use erythromycin
DOC for legionella species
Azithromycin
DOC for mycoplasma pneumoniae
Erythromycin, also tetracycline would work
Spectrum for macrolides
similar to PEN G, G+
most species resistant to erythromycin
Forms of resistance against macrolides
METHYLATION, efflux pumps
Toxicity of macrolides
diarrhea and adverse GI effects: clarithro least, erythro most long QT: azithro most, than erythro drug interactions (CYP3A4): clarithro and erythro most
Name the only ketolide drug
Telithromycin
MOA of telithromycin
binds to two places on the 50s subunit, bacteriostatic
spectrum of telithromycin
respiratory pathogens, resistant strains of pneumonia, intracellular and atypical bacteria
route of administration for telithromycin
oral
most common side effects of telithromycin
diarrhea, n/v, dizziness
MOA of clindamycin
binds to the 50s subunit, bacteriostatic or cidal depending on concentration and organism susceptibility
spectrum of clindamycin
broad
G+ aerobes
G+ and G- anaerobes
toxicity of clindamycin
CDAD: c.diff associated diarrhea
crosses placenta readily and gets into breast milk, avoid while nursing
use for clindamycin
osteomyelitis (good bone concentration)
TSS: use with vancomycin
streptococci and staphylococci extremely susceptible
toxoplasma encephalitis
Name the streptogramins
Dalfopristin and quinupristin
MOA of streptogramins
each static but together cidal
act on 50s subunit
dalfopristin acts in early phase while quinuprisitn acts in late phase
route of administration of synercid
IV
spectrum of synercid
Gram + aerobes including:
penicillin resistant pneumonia, MDR strep, complicated skin infections due to staph, vanco resistant enterococcus
major adverse reactions of synercid
inhibits p450 system, CYP3A4
contraindications of synercid
breast feeding, children, hepatic disease, pregnancy
MOA of linezolid
binds to 50s subunit, bacteriostatic (except strep)
reversible, non-selective inhibitor of MAO
spectrum of linezolid
G+, reserve for MRD bacteria if possible
route of administration of linezolid
IV or oral, oral is 100% bioavailable
Adverse reactions of linezolid
diarrhea, headache, n/v
MAO side effects
insomnia, constipation, rash, dizziness, fever
superinfection can occur
contraindications of linezolid
hypersensitivity, pheochromcytoma
drug interactions of linezolid
b-blockers, general anesthetics, epi, SSRI, TCA, other antidepressants
MOA of aminoglycocides
30s subunit, irreversible
Block initiation, translation, and incorporate the wrong amino acid
spectrum of aminoglycosides
aerobic G- enteric bacteria
when sepsis or endocarditis is suspected
use for streptomycin
tularemia, bubonic plague, TB, endocarditis
DOC for tularemia
gentamycin
DOC for pseudomonas aeruginosa
piperacillin or ticaracillin +
gentamycin/tobramycin/amikacin
DOC for enterococcus and strep. agalactiae
PEN G + gentamycin
toxicity of aminoglycosides
ototoxicity and nephrotoxicity
dependent on time and concentration
route of administration for aminoglycosides
IV, oral, topical
resistance of aminoglycosides
cross resistance: resistant to one, resistant to all
deficiency of ribosomal receptors, lack of permeability, enzyme modification
MOA for chloramphenicol
bacteriostatic (mostly)
binds to 50s subunit
can also inhibit mito protein synthesis in mammalian cells
spectrum for chloramphenicol
G+, G-, aerobes and anaerobes, atypicas
for life threatening situations
route of administration for chloramphenicol
parental, 100% CNS penetration
toxicity of chloramphenicol
reversible dose dependent bone marrow suppression
irreversible dose independent fatal aplastic anemia
gray baby syndrome, immature liver enzymes
chloramphenicol resistance
acetyl transferase inactivates chloramphenicol
efflux pumps
binding site modification
MOA for tetracycline
binds to 30s ribosome, bacteriostatic
spectrum for tetracycline
broad spectrum
G+, G-, aerobes, anaerobes, atypicals
organisms resistant to tetracyclines
b. fragilis, proteus, pseudomonas
Name cases were tetracycline is DOC
Cholera, Mycoplasma Pneumonia, Chlamydia, Ricketssial, Lyme disease (early disease), vibrio species
tetracycline resistance
efflux pumps
if tetracycline resistant, may still use doxy or minocycline
route of administration for tetracycline
oral
adverse reactions of tetracyclines
normal flora changes, bone and teeth (chelators), photosensitivity
contraindications for tetracyclines
pregnant women or children under 8 years old
route of administration tigecycline
IV
life threatening situations
spectrum of tigecycline
same as tetracyclines, but also on tetracycline resistant bacteria, MRSA, MRSE, PRSP, VRE
MOA of penicillins
inhibitor of cell wall synthesis, PBP, bactericidal
method of resistance for penicillins
b-lactamases