Antibiotics Flashcards
penicillin mechanism
inactivates transpeptidase from cross-linking peptidoglycan
penicillin clinical use
gram positive (Strep pneumo, Staph pyogenes, Actinomyces) Gram negative (Neisseria meningitis, treponema palladium)
penicillin reistance mechs
altered penicillin binding proteins (MRSA) and beta-lacatamases
oxacillin, nafcillin, dicloxacillin: what are they, uses?
beta-lactamase resistant cause R group. use for Staph aureus except for MRSA (use naf for staph”
Ampicillin, amoxicillin are what?
extended spectrum penicillin (still penicillinase sensitive)
beta-lactamase inhibitors
Clavulanic Acid, Sulbactam, Tazobactam (CAST)
ampicillin amoxicilin uses
same as penicillin but also HELPSS: H flu, E. coli, Listeria, Proteus mirabilis, Salmonella, Shigella
ampicillin and amoxicillin toxicity
ampicillin rash, pseudomembranous colitis (C diff)
Ticarcillin, piperaciliin
anti-pseudomonals (lactamse sensitive)
Cephalosporin mechanism
they are beta lactams that are penicillinase resistant
1st gen cephalosporins
cefazolin, cephalexin
1st gen cephalosporin uses
PEcK: proteusmirabilis, E. coli, Klebsiella
2nd gen cephalosporin names
cefoxitin, cefaclor, cefuroxime
2nd gen cephalosporin uses
gram + cocci, HEN PEcKS: H flu, Enterbacter aerogenes, Neisseria, Proteus, E. coli, Klebsiella, Serratia
3rd gen Cephalosporins
ceftriaxone, cefotaxime, ceftazidime
3rd gen cephalosporin uses
serious gram negative infxns. ceftriaxone: neisseria. ceftazidime: pseudomonas
4th gen cephalosporin name and use
cefepime, pseudomonas and gram positives
toxicity of cephalosporins
vitamin k def, nephrotox when used with aminoglycosides
what can be used synergistically with beta-lactams?
aminoglycosides
aztreonam mech and use
monobactam (a beta lactam resistant to degradation). only Gram negative rods and used in patients who can tolerate other stuff cause this has low toxicity
Imipenem/cilastatin, meropenem mech
broad spectrum beta lactam that is resistant to degrad. give with cilastatin to prevent inactivation in kidneys
imipenem/cilastatin, meropenem use
kills almost everything: gram + cocci, gram - rods, and anaerobes. but lots of sides so only use in life-threatening
imipenem/cilastatin, meropenem tox
Gi distress, skin rash, CNS tox
vancomycin mechanism
inhibits cell wall synthesis by binding to D-ala D-ala portion of precursor
vancomycin uses
gram + only for serious drug-reistant bugs including MRSA, Enterococci, and C diff
vancomycin toxicity
NOT: nephrotox, ototox, thrombophlebitis
and Redman!!! causes diffuse flushing which can be treated with antihistamine
vancomycin resistance
D-ala D-ala changes to D-ala D-lac
which drugs hit 30S vs 50S
buy AT 30, CCEL at 50
30: Aminoglycosides, tetracyclines
50: Chloramphenicol, Clindamycin, Erythromycin, Linezolid
Aminoglycosides (names)
GNATS: gentamicin, neomycin, amikacin, tobramycin, streptomycin
drug given with bowel surgery
neomycin (aminoglycoside)
aminoglycoside mechanism
bind 30S and inhibits formation of initiation complex and misreading of mRNA/translocation
aminoglycoside uptake
requires ATP and oxygen. does not kill anaerobes
aminoglycoside use
synergistic with beta lactams, used for severe gram - rods
aminoglycoside toxicity
NNOT: nephrotoxicity (worse with cephalosporine), neuromuscular blockade, otoxicity (worse with furosimide), teratogen
aminoglycoside resistance
transferase enzymes inactivate it by PTMs
aminoglycoside mneumonic
Mean (aminoglyco) GNATS (names) caNNOT (tox) kill anaerobes
tetracyclin names
tetracycline, doxycyclin, demeclocycline, minocycline
tetracycline mechanism
bind 30S to prevent attachment of aminoacyl-tRNA.
tetracycline clinical notes (not targets but indications)
fecally eliminated (so for renal failure), no CNS penetrance, don’t take with milk/antacids/iron or it won’t be absorbed.
tetracycline uses (bugs)
borrelia burgdorferi, Mycobacterium pneumoniae, and it accumulates intracellularly so very effective against rickettsia and chlfamydia
tetracycline toxicity
GI distress, discoloration of teeth and retardation of bone growht in children, photosensitivity
tetracycline resistance mech
decrease uptake or increase efflux
Macrolides (names)
Azithromycin, clarithromycin, erythromycin (-thromycin)
macrolide mechanism
blocks ribosome slide (macroslide) by bindings 23S of 50S
macrolide uses
atypical pneumonias (mycoplasma, legionella), Chlamydia, and gram + cocci (for penicillin allergy)
macrolide toxicities
MACRO: motility issues, arrhthymia, cholestatic hepatitis, rash, eOsinophilia. also increases theophylline/anticoag serum concentration
macrolide resistance mech
methylation of 23S rRNA binding site
Chloramphenicol mech
blocks peptidyltransferase at 50S
chloramphenicol use
Meningiits (H flu, N meningitidis, S pneumo).
it sucks cause of tox but is cheap as fuck
chloramphenicol tox
anemia (dose dependent), aplastic anemia (dose dependent), gray baby syndrome
Clindamycin mech
blocks peptide transfer at 50S
clindamycin use
anaerobic infections, aspiration pneumonia. however may cause C diff
treating anaerobes
above diaphram: clindamycin
below diaphram: metronidazole
TMP-SMX name and mech
Sulfamethoxazole-Trimethoprim. they block different steps in bacterial folate (THF to DNA) synthesis
sulfonamides tox
like SMX. hypersen, hemolysis in G6PD, nephrotox, phototox, kernicterus in infant, displaces other drugs from albumin
TMP-SMX use
UTIs, Shigella, Salmonella, Pneumocystis jiroveciii
Fluoroquinolones and quinolone (names)
Ciprofloxacin (all -floxacin) and the one quinolone (nalidixic acid)
Flouroquinolone mechanism
inhibits dna gyrase (topoisomerase II) and topoisomerase IV
Fluoroquinolone use
gram - rods of urinary and GI tract, pseudo, neisseria
Fluoroquinolone tox
tendon rupture, tendonitis, superinfxn, skin rash, gi upset
fluoroquinolone resistance
chromosome via DNA gyras muts, or plasmid via efflux pumps
metronidazole mech
forms free radicals that damage DNA
metronidazole uses
kills bacteria and protozoa! GET GAP: giardia, entamoeba, trichomonas, gardnerella vaginalis, anaerobes, h Pylori
Penicillin G vs V
G is IV/IM, V is oral
treatment for mycobacterium tuberculosis
prophylaxis: isoniazid
treatment: RIPE: Rifampin, Isoniazid, Pyrazinamide, Ethambutol
Isoniazid mech
decreases mycolic acid synth. bacterial catalase-peroxidase (KatG) needed to covert to active form.
Isoniazid side efects
INH Injures Neurons and Hepatocytes. B6 (pyridoxine) to prevent.
Rifampin mechanism
inhibits DNA-dependent RNA pol
Rifampin uses
TB, leprosy, meningococcal/h flu prophylaxis
Rifampin tox
activates P-450, Orange body fluids
RRRRifampin
RNA pol inhib, Revs up P-450, Red/orange body fluids, Rapid resistance if used alone
Pyrazinamide
mech unclear, helps acidicify phagolysosome (which MB sulfatides block)
Ethambutol
decreasese carbohydrate polymerization in mycobacterium cell wall (arabinosyltransferase). may cause optic neuropathy/color blindness
