Antibiotics Flashcards
G+ cocci and bacilli; some G- cocci; spirochetes (streptococcus, treponema pallidum, neisseria gonorrhoeae): penicillins G and penicillins V
natural penicillins
B lactamase producing staph (penicillinase resistant): nafcillin, oxacillin, dicloxacillin
anti-staphylococcal
same as Pen G, plus some G- rods and bacilli; not resistant to broad spectrum B lactamases in G- organisms (H. influenzae, E coli): ampicillin, amoxicillin, cyclacillin
extended spectrum
enteric G- rods, G- bacilli; usually combined with an aminoglycoside for serious infections (pseudomonas aeruginosa, H. influenzae): ticarcillin, mezclocillin, piperacillin
anti-pseudomonal
clavulanic acid, sulbactam, tazobactam
b lactamase inhibitors
amoxicillin and clavulanic acid (oral): B lactamase producing Staph
augmentin
ampicillin and sulbactam (parenteral)
unasyn
ticarcillin and clavulanic acid (parenteral)
timentin
piperacillin and tazobactam (parenteral): gram neg. bacilli; not pseudomonas
zosyn
penicillins that have biliary excretion
nafcillin and oxacillin
treat MRSA with…
vancomycin
diarrhea after oral dose is more common with …
ampicillin and augmentin
first gen. cephalosporin; similar spectrum to ampicillin; G+ cocci; some G- bacilli
cephalothin and cefazolin
second gen. cephalosporin; less active for G+ and more active for G-; H. influenza, N. meningitidis
cefoxitin, cefotetan, cefaclor
third gen. cephalosporin; enteric G-; reserve for very serious infections; crosses BBB; h. influenza, serratia
cefotaxime, ceftriaxone, ceftazidime, cefixime
b. fragilis
cefoxitin and cefotetan
pseudomonas
ceftazidime only
fourth gen cephalosporin; increase activity for G+, B lactamase producing organisms, broad spectrum
cefepime and ceftaroline
which 4th gen ceph? p. aeruginosa, klebsiella, e coli, enterobacter, citrobacter, proteus mirabilis
cefepime
which 4th gen ceph? s aureus (MRSA and MSSA), s pneumoniae, E coli, klebsiella, enterobacter, citrobacter
cerftaroline
no current cephs have activity for …
enterococcus
3rd gen; penetrate to CSF sufficiently to be useful for treatment of meningitis
cefotaxime and ceftriaxone
extra dose required after hemodialysis except for …
ceftriaxone
disulfiram like effects w/ alcohol for cephs with N-methylthiotetrazole side chain –> i.e. …
cefotetan
B lactam ring; more resistant to beta lactamase enzymes than penicillins and cephalosporins; broadest spectrum of any b lactam; IV
carbapenems-imipenem
carbapenems-imipenem is administered with … which inhibits dehydropeptidase and prevents breakdown in kidney and renal toxicity
cilastatin
fixed combo of carbapenem and cilastatin
primaxin
active against p. aeruginosa, resistant nosocomial gram negatives, role in empiric therapy
carbapenems
carbapenem that doesnt require co administration with cilastatin; slightly less likely to cause seizures; active against imipenem resistant p. aeruginosa and extended spectrum b lactamases producing E coli and klesbsiella
meropenem
carbapenem with longer serum half life; once a day dosing
ertapenem
inhibits cell wall synthesis but with different site from other B lactams; narrow spectrum-primarily against G+; glomerular filtration half life a lot longer with renal impairment; nephrotoxicity which increases when in combo with aminoglycoside, cyclosporin, amphotericin; used against MRSA
vancomycin
erythromycin, clindamycin, azithromycin
macrolides
binds to 50s subunit and inhibits protein synthesis; bacteriostatic; narrow spectrum- high uptake in G+ and low in G-; oral but in protected form; concentrated in liver and excreted in bile; renal failure has no effect; inhibits cytochrome P450; can trigger heart arrhythmia; 2nd after Pen G for G+ infections
erythromycin
more acid stable than erythromycin; absorption of oral dose increases with food; longer half life; slightly better activity against G+; similar in effectiveness to Pen Vs; slightly less inhibiting of cytochrome P450 than erythromycin but still does inhibit it;
clarithromycin
more acid stable; very long half life; absorption of oral dose reduced with food; concentrates in macrophages, neutrophils and fibroblasts; increased penetration in G-; NO inhibition of CYP enzymes; small increased risk for cardiac death
azithromycin
drug of choice for legionella, campylobacter, mycobacterium avium complex
azithromycin
inhibition of protein synthesis; binds to 50S; cross resistance to the macrolide antibiotics; penetrates bone; spectrum includes many of the orodental pathogens; G+ cocci; anaerobic G+ and G-; prophylactic coverage with allergic to penicillin
clindamycin
inhibition of protein synthesis by binding to 30S; bacteriostatic with reversible binding to ribosome; broad spectrum; G+ and G-; aerobic and anaerobic
tetracycline
may be drug of choice for mycoplasma, chlamydia, rickettsiae; spirochetes
tetracycline
resistance to one tetracycline provides resistance to …
all tetracyclines
absorption inhibited by di- and trivalent cations; best absorbed in acidic conditions of stomach w/o antacids; concentrates in bone and teeth particularly when undergoing calcification; fetal conc. can be relatively high in bond and dentition; excreted to the bile
tetracycline
which tetracyclines use hepatic excretion
minocycline and doxycycline
adverse effects: avitaminosis (B vitamins produced by flora in gut); superinfections common; discoloration of teeth during development
tetracycline
which tetracyline is more completely absorbed and least likely to cause problem
doxycycline
induced staining of dentition in adults; vestibular toxicity
minocycline
enzymatic reduction of drug by to cause effects on bacterial DNA replication; penetrates CSF; can by used to treat clostridium difficile; active against G- anaerobes found in acute orofacial infections, refractory/rapidly progressive periodontitis; protozoal infections; inhibits P450 isozyme; disulfiram effect
metronidazole
ciprofloxacin, norfloxacin, sparfloxacin
fluoroquinolones
inhibition of bacterial DNA gyrase, inhibits DNA synthesis, bacteriocidal; absorption decreases with antacids containing Al+++ and Mg++ and decreases with dietary supplements containing Fe++ and Zn++; accumulates in macrophages and leukocytes–>effective against intracellular organism (legionella); poor CSF penetration; half life increases with renal failure; broad spectrum
fluoroquinolones
alterations in DNA gyrase binding is caused by mutation to … of DNA gyrase enzyme
QRDR gene
resistance to fluoroquinolones becoming frequent in …
S. aureua and P. aeruginosa
which generation of fluoroquinolones?: increased G- and systemic activity; improved pharmacokinetics; fewer side effects
2nd gen
which generation of fluoroquinolones?: extended activity against G+; broad G- coverage
3rd gen
which generation of fluoroquinolones?: activity against anaerobes along with G+ and G- of 3rd generation
4th gen
which generation of fluoroquinolones?: ciprofloxacin, enoxacin, lomefloxacin, norfloxacin, ofloxacin
2nd gen
which generation of fluoroquinolones?: grepafloxacin, levofloxacin, sparfloxacin
3rd gen
which generation of fluoroquinolones?: gatifloxacin and moxifloxacin
4th gen
fluoroquinolones have poor CSF penetration except …
ofloxacin
adverse effects: prolongation of QT interval (3rd gen except levofloxacin); articular cartilage erosion (arthropathy) drug interactions: inhibition of P450 system
fluoroquinolones
a fluroquinolone with definite risk of QTc prolongation
sparfloxacin
fluoroquinolones with possible risk of QTc prolongation
gatifloxacin, gemifloxacin, levofloxacin, moxifloxacin, ofloxcin
fluoroquinolone to avoid in patients with or suspected to have congenital long QT syndrome, hypokalemia, or receiving Class IA or Class III antiarrhythmic agents
ciprofloxacin
inhibit utilization of PABA in the synthesis of folic acid; bacteriostatic; pass the placental barrier and into breast milk; hematologic disorders in G6PD deficiency; sulfonamide binds serum albumin and displaces other drugs
sulfonamides
inhibits reduction of dihydrofolate to tetrahydrofolate; resistance comes from alteration in enzyme affinity; concentrates in prostate and vaginal fluids; synergistic with sulfonamides
trimethoprim
trimethoprim-sulfamethoxazole combo
co-trimoxazole
