Sweatman Staph and Strep Antibiotics Flashcards
MOA for Daptomycin
Cyclic lipopeptide that rapidly disrupts bacterial cell membranes
*depolarization and efflux of K+
resistance to Daptomycin
rare at present, no MOR identified, no known transferable resistance gene
administration of daptomycin
IV once daily
Toxicities with Daptomycin
direct muscle injury preclude IM injection
administer after dialysis
Met and Elim for daptomycin
90% bound to albumin
Renal elim with DOSE ADJUSTMENT (no adjutment for hepatic)
side effects of Daptomycin
monitor serum CPK elevation
*avoid coinciciding statins–>
rhabdomyolysis
NO CYP interactions
what type of bacteria get Daptomycin
aerobic, gram positive
MDR staph, strep and enterococcus
therapuetic indications for daptomycin
MRD staph, strep and enteroccocus
*complicated skin and soft tissue infections
MSSA and MRSA bacteremia
*right side endocarditis–> IVDU
do not use daptomycin in
staph pneumonia–> inactivated by surfactant
MOA for linezolid
inhibits protein synthesis by inhibiting 23s of 50s ribosomal subunit
linezolid is bacteriostatic for
staph and enterococci
linezolid is bacteriocidal for
strep
MOR for Linezolid
pt. mutation inf 23s subunit, no cross resistance with other classes,
(EMERGING RESISTANCE SEEN IN STAPH AUREUS AND ENTEROCCOCUS)
indications for linezolid
PENICILLIN RESISTANT SA–>
MRSA
ENTEROCOCCUS
RESERVE FOR VANC RESISTANT ENTEROCOCCUS
PK/PD OF LINEZOLID
ORAL AND IV ROUTES 100% absorption of oral-. delayed by food but not peak drug levels metabolized by NEoxidation elim=renal and non renal mechs No renal adjustment NO cyp inh/ind suppl dose needed following hemodialysis
possible side effect with LInezolid
pseumomembranous cholitis myelosupression after 2 weeks (thrombocytopenia, anemia, neutropenia) Optic and peripheral neuropathy, lactic acidosis N/V/D/HA
PKU pt.’s beware
of linezolid–> contains aspartame in the oral suspension form
drug interations with linezolid
inihibitor of MAO–> caution with other drugs metabolized by MAO
ex. psuedaphed, phenylephrine, SSRI’s,
POSSIBLE SEROTONIN SYNDROME
possible HTn from decreased breakdown of ttyramine in the diet
Streptogrammins
dalfopristin-quinipristin (70-30)
remotely related to macrolides but no cross reactivity
oxazolidinones
Linezolid
MOA for dalfopristin-quinipristin
protein synthesis inhibition
(bind to ribosyl peptidyl transferase domain)
tRNA synthase is inhibited
aa addition to peptide chain is blocked
action on bacteria for syndercid
“synergistic bacteriocidal combination”
resistance to Synercid
changes in 23s ribosomal target site
erm gene encoding MLSb phenotype
pharmacology of Syncercid
IV only–> central line best
hepatic metab- conjugation via CYP 3A4
*metabolites still have activity
BILLIARY EXCERETION
if unabel to tolerate synercid
increase dosing from Q8 HRS TO Q12 HRS
ADverRSE EFFECTS OF SYNCERCID
thrombophlebitis pain at injection site inrease conj. bilirubin Elevated LEnzymes Joint pain (in chronic liver dz) inhibits CYP 3A4
Syncerid through its action with CY3a4 wil increase the concent. of
cyclosporin, midazolam, statins, HIV protease inhibitors
Spectrum for Streptogrammins
Dalfopristin-Quinipristin
> gram positive (not enterococcus faecalis)
VRE-> Enterococcus faecium
Skin and SKin Strcuture infections SSI’s from MRSA or Strep Pyogenes
bone infection from VRE and MRSA
name the glycylcyline
tigecylcine
MOA for tigecycline
SIMILAR TO TETRACYCLINES
inhibits protein translation but binding to 30s subunit
*expanded broad spectrum
resistance to Tigecycline
overcomes key mechs of resistance to tetracylcine by
- higher binding affinity to more ribosomal sites
- no efflux
Pharmacology to tigecycline
- slow IV infusion
- lower dose with liver failure
- no renal adjustment
- extensive distribution beyond plasma volumes and into tissue
- Very little metab–> 1/2 life= 27hours
- excretion= billiary/fecal and renal
adverse effects of Tigecycline
Hepatic and pancreatic toxicity
Teeth, bones, photosensitivity, superinfections
NVD, injection site pain,
Spectrum of Tigecycline
BROAD SPECTRUM= gram +, gram-, anaerobes, MRSA
>SSTI’S AND INTRABDOMINAL INFECTIONS,
*no activity against pseudomonas or proteus
TIGECYLINE CANNOT BE SUED IN
PATIENTS UNDER 18
RIFAMPIN MOA
Rifampicin inhibits bacterial DNA-dependent RNA synthesis by inhibiting bacterial DNA-dependent RNA polymerase–> inhibiting protein synthesis
spectrum of Rifampin
- MRSA (in combo with beta lactam or vanc)
- TB primary agent
- leprosy
- staph epi
rifampin when use to treat staph aureus, MRSA or Staph epi…
is combined with Vancomycin or a beta lactam
another use of Rifampin for prophylaxis
household members exposed to H FLu
Rifampin causes eradication of _____ in ______
staph in nasal carriers
Most active anti-leprosy drug at present
rifmapin
another is dapsone
another is clofazimine
MOA for clindamycin
inhibits protein synthesis byt binding up the 50s ribosomal subunit,
- very similar to erythromycin
- not effective if erythromycin and clinda re given together
MOR for clinda
slowly and step-wise
Methylation of erm encoded genes
Spectrum for clindamycin
ANAEROBES *BOTH GRAM + AND GRAM - *PEPTOSTREP, BACTEROIDES, ACTINOMYCES MRSA AND GROUP A STREP
PHARMACOLOGY OF CLINDAMYCIN
NEAR COMPLETE ORAL ABSORPTION
rapid
widely dist, PENETRATES BONE AND ABCESSES
*does not penetrate CSF onr intracellular
does not cross placenta and is found in breast milk
metabolism of clinda
liver–. adjustment for liver fialure
half life is 2.7 hours
is clinda removed by hemodialysis
no
_
excretions of clinda
bile and urine excrete metabolites from liver breakdown
No renal adjustment
Side effect of Clindamycin
PSUEDOMEMBRANOUS COLITIS from C. Diff.
-hypersensitivity and diarrhea
tx for Pseudomembrandous colitis in clinda therapy
metronidazole or vancomycin
spectrum of clindamycin
bacteroides fragilis (outside CNS–> no access)
- oral infections (peptostrep)
- toxo in AIDS with pyrimethine
- prophylaxis with penicillin allergy (staph and strep) MSSA and MRSA of soft tissue
- for PCP with primaquine
Mupirocin MOA
BINDS REVERSIBLY TO STAPH ISOLEUCYL TRNA SYNTHETASE
-inhibits rna and protien synthesis
SPECTRUM FOR MUPIROCIN
TOPICALLY FOR IMPETIGO
- GRAM + BACTERIA**
- STAPH
- STREP
- MRSA
SYSTEMIC ABSORPTIONS WITH MUPIROCIN
LITTLE
ADEVRSE EFFECTS WITH MURPIROCIN
VEHICLE PEG can cause renal failure
polypeptide antibiotic
bacitracin
MOA for bacitracin
inhibits cell wall synthesis by inihbiting movement of peptidoglycan building blocks of the cell wall from inside to outside the cell membrane by INHIBITING DEPHOSPHORYLATION OF ISOPRENYL PYROPHOSPHATE CARRIER PROTEIN
spectrum Bacitracin
gram + cocci and bacilli
Major adverse effect with bacitracin
nephro toxicity with IV
*used topically with neomycin and polymyxin B
MOA for vancomycin
binds to the D-Ala-D-Ala prevents cell wall synthesis of the long polymers of N-acetylmuramic acid (NAM) and N-acetylglucosamine (NAG) that form the backbone strands of the bacterial cell wall, and it prevents the backbone polymers that do manage to form from cross-linking with each other.
major VANC adverse effects
nephro and ototoxicity
review MOAS for penicillin, anti-staph penicillin, cephs, vanc, azithromycin, bactrim,
pk