Micro Flashcards
High risk for endocarditis and undergoing
surgical or dental procedures
Amoxicillin
Exposure to gonorrhea
Ceftriaxone
Prophylaxis of strep pharyngitis in child with prior rheumatic fever
Benzathine penicillin G or oral penicillin V
Exposure to syphilis
Benzathine penicillin G
Prevention of postsurgical infection due to S aureus
Cefazolin
Cefazolin
Prevention of gonococcal conjunctivitis in
newborn
Erythromycin ointment on eyes
Pregnant woman carrying group B strep
Intrapartum penicillin G or ampicillin
History of recurrent UTIs
TMP-SMX
Exposure to meningococcal infection
Ceftriaxone, ciprofloxacin, or rifampin
MRSA:
vancomycin, daptomycin, linezolid, tigecycline, ceftaroline.
VRE:
linezolid and streptogramins (quinupristin, dalfopristin).
Multidrug-resistant P aeruginosa, multidrug-resistant Acinetobacter baumannii:
polymyxins B and
E (colistin)
Autoclave
Pressurized steam at > 120°C. May be sporicidal.
Alcohols
Denature proteins and disrupt cell membranes. Not sporicidal.
Chlorhexidine
Denatures proteins and disrupts cell membranes. Not sporicidal.
Iodine and iodophors
Halogenation of DNA, RNA, and proteins. May be sporicidal
Hydrogen peroxide
Free radical oxidation. Sporicidal.
Mechanism of Resistance:
production of beta lactamases, which cleave the beta lactic ring structure; change in penicillin binding proteins; change in porins
penicillins and cephalosporins
Mechanism of Resistance:
formation of enzymes that inactivate drugs via conjugation reactions that transfer acetyl, phosphoric or adenylyl groups
aminoglycosides (gentamicin; streptomycin; amikacin, etc.)
Mechanism of Resistance:
formation of methyltransferases that alter drug binding sites on the 50s ribosomal subunit
Active transport out of cells
macrolides (erythromycin, azithromycin, clarithromycin, etc.) and clindamycin
Mechanism of Resistance:
increased anti its of transport systems that “pump” drugs out of the cell
tetracyclines
Mechanism of Resistance:
changes in sensitivity to inhibition of target enzyme; increased formation of PABA; use of exogenous folic acid
sulfonamides
Mechanism of Resistance:
change in sensitivity to inhibition of target enzymes; increased activity of transport systems that promote drug efflux
fluoroquinolones
Mechanism of Resistance:
formation of inactivating acetyltransferases
chloramphenicol
Penicillins have enhanced activity when used in combination with beta lactase inhibitors such as
clavulanic acid or sulbactam
- these are suicide inhibitors
Naficillin and oxacillin are excreted largely in the _______. And ampicillin undergoes extrahepatic cycling but excreted via the ______.
biles; kidney
macrocyclic antibiotic (related to macrolides) that inhibits the sigma subunit of RNA polymerase, leading to protein synthesis impairment and cell death ( it is bactericidal against C. difficle)
fidamoxicin
Binds to ergosterol
amphotericin B and nystatin
Inhibition of squalene epoxidase
terbinafine
blocks beta-D gluten synthesis
capsofungin
* works on main component of cell walls (candida and aspergillus)
Prevents mitosis by binding tubulin
griseofulvin
inhibits fungal protein synthesis
flucytosine
Empirically used to treat skin and soft tissue infections ( folliculitis and abscesses) for which Staph aureus is the usual cause?
nafcillin
