ABX review Flashcards
Bactericidal agents important when patient is already immunocompromised
beta lactams bacitracin Fosomycin Vanco Isoniazid Aminoglycosides Quinpristin Metronidazole Polymixins (colistin) Fluroqionolones (-floxacins) Tigecylcine Rifampin Pyrazinamide
Microbial resistance of beta lactams via
altered targets, decreased permeability, enzymatic inactivation
main classes of GI superinfections
Intestinal Candidiasis (tx oral nystatin) Staph Enterocolitis (life threatening, oral vancomycin) Pseudomembranous colitis (C. diff usually from clinda; tx metronidazole, vanco if resistant)
Inhibitors of cell wall synthesis intracellular agents
Fosomycin
Cycloserine
Bacitracin stops the transport of building blocks out of the cell as well
Inhibitors of cell wall synthesis extracellular transglycosylation and transpeptidation
transglycosylation: Vancomycin
Transpeptidation: makes cell wall rigid–> Beta-lactams
GM+ beta lactams, antistaph, and extended spectrum
GM+: Pen V and Pen B
Anti staph: nafcillin, methicillin, isoxazolyl penicillins
Extended spectrum: Ampicillin, Amoxacillin, piperacillin, Ticarcillin
What are the anti pseudomonal penicillins
Piperacillin, ticarcillin (rapid resistance so use in combo with aminoglycoside)
cephalosporins are inhibitors of cell wall synthesis via intracellular mechanisms 1st through 5th gen speificity
1st gen cephalosporin (cefazolin parenteral, cephalexin oral)–> GM+
2nd gen cephalosporin (cefaclor oral)–> GM+ and increased against GM-
3rd gen (Ceftriaxone, cefotaxime, cefexime oral)–>GM-
4th gen (cefepime)–> GM+ and GM- activity
1st gen cephalosporin (cefazolin parenteral, cephalexin oral) used for
Staph and strep cellulitis, surgical prophylaxis except abdominal which you use a 2nd gen sporin for
2nd gen cephalosporin (cefaclor oral) uses
E. coli, kliebsiella, proteus, H. flu, Moraxella catarrhalis
PID, Diverticulitis, Surgical prophylaxis (for abdominal surgery), pneumonia, bronchitis (H. flu)
3rd gen (Ceftriaxone, cefotaxime, cefexime oral) uses
Ceftazidine--> pseudomonas Ceftazidime-->osteomyelitis Ceftriaxone-->Meningitidis N. gonorrhea Ceftriaxone (parenteral) or Cefexime(oral)--> Gonorhea CAP Lyme disease
Cross the BBB, helpful for meninigitis
4th gen (cefepime) uses
GM+ and GM—> neutropenic fever
5th gen cephalosporin uses
MRSA, CAP, skin infections
Beta lactam that you can use with penicillin allergy with aminoglycoside to treat pseudomonas
Aztreonam
Beta lactam that is inactivated by renal dipeptidase so administer with cilastatin
Carbapenems; pseudomonas develops resistance rapidly, administer with aminoglycoside
IV only
penems that aren’t inactivated by renal dipeptidase
Meropenem, doripenem, ertapenem
Abx that inhibits transglycosylation of cell wall synthesis, works against GM+ cillin resistant and is orally administers for tx of C. diff
Vancomycin
Abx that causes Red man syndrome, ototoxicity, renal toxicity which has synergistic toxicity with aminoglycosides
Vancomycin
Vancomycin used for
S. aureus Hospital acquired MRSA Enterococci species GM+ in penicillin allergies C. diff though metronidazole DOC
Abx that inhibits cytoplasmic step in cell wall precursory synthesis
Fosfomycin, transported into cell via G6P transporter
single dose tx of UTIs
Bacitracin acts intracellularly to inhibit cell wall synthesis, is only GM+ and topical, and has was sort of toxicity that makes it used only topically
Nephrotoxicity
MOA of quinolones
DNA gyrase inhibitor, block the unwinding of DNA
Why are quinolones fluorinated?
to slow down the clearance, probenacid can also help with this.
1st, 2nd, 3rd, 4th gen fluoroquinolones
nor cipping levt (over) Moxi
1st gen: norfloxacin (UTIs)
2nd gen: Ciprofloxacin BID (Gonococcus and Pseudomonas, Chlamydi, Myco pneumo)
3rd gen: Levofloxacin (S. pneumo, enterococci, MRSA, Drug resistant Respiratory tract infections)
4th gen: Moxifloxacin/gemifloxacin “Respiratory Abx”
Main tx for TB and leprosy that inhibits DNA dependent RNA polymerase
chronic tx with isoniazid and Rifampin
What is preferred in the tx of TB or leprosys in pts with HIV who are on HAART
Rifabutin
Nitrofurantoin used for ______ because it is excreted rapidly and even when IV it doesn’t have systemic distribution
UTIs
need acidified urin
some G6PDase hem anemia
What Abx makes the cell wall more permeable?
polymixins for GM-, mainly topical
mainly topical because of systemic toxicity (NEPHROTOXIC)
Colistin is used as last resort for Pseudomonas
Abx that binds to the cell membrane and causes cell depolarization, used only for GM+, IV, Severe skin infections or VRE
Daptomycin
Abx that binds to isoleucyl transfer-RNA synthetase, used topically for impetigo (staph aureues or streptococcus pyogenes)
Mupirocin
Prophylaxis for Pneumocysitis jirovecii
TMP-Sulfamethoxazole
Prophylaxis for malaria
Chloroquine
Prophylaxis for TB
Isoniazid
prophylaxis for Mycobacterium avium in AIDs patients
Azithromycin
