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23 Cards in this Set
- Front
- Back
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Name the beta lactams that are NOT elminated by the kidney
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nafcillin, oxacillin, ceftriaxone (biliary) and cefperazone
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Which drug does not exhibit cross-allergenicity with other beta-lactams?
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Aztreonam.
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What are the structural differences of cephalosporins vs penicllins?
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Cephalosporins have a beta-lactam ring attached to a 6 membered dihydrothiazine ring which confers greater stability against some beta-lactamase enzymes
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How to cephalosporins kill bacteria?
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They kill bacteria in the same manner as penicillins - by inhibiting cell wall synthesis by inhibiting PBP.
FYI - bacteria cephalosporin resistance is the same as penicillin resistance as well |
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Name the first generation cephalosporins and what they are best used for.
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Cefazolin (parenteral) and cephalexin (oral). They have their best activity against gram + aerobes (meth-susc STAPH AUREUS, pen-susc S. pneumoniae, Group strep and viridins strep)
VS Gram negatives they are good against PEK (P. miribilis, E. coli, Klebsiella pneumoniae |
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Name the second generation cephalosporins and their target bacteria
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Cefoxitin, cefotetan.... and cefuroxime and cefprozil
Same as first genereation (meth susc staph aureus, pen-susc S. pneumoniae, group strep and viridans strep). And for the gram negatives they are good vs HENPEK H. influenzae Enterobacter spp (some) Neisseria spp P. miriabilis E. coli Klebsiella pneumoniae |
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What cephalosporins do you use to treat the anaerobes Bacteroides fragilis and Bacteroides fragilis group?
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The cephamycins: cefoxitin, cefotetan and cefuroxime.
These are second generation cephalosporins |
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Name the third generation cephalosporins and their target organisms
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Ceftazidime is the preferred (ceftriaxone is also used). They are used to treat HENPEKSSS
H. influenzae Enterobacter spp (some) Neisseria spp P. mirabilis E. coli Klebsiella pneumoniae Shigella Salmonella Serratia marcescens PSEUDOMONAS AERUGINOSA is a target organism |
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Name the 4th generation cephalosporin and its target.
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Cefepime. Its good for HENPEKSSS and is HIGHLIGHTED for being useful against Pseudomonas aeruginosa and beta lactamase producing Enterbacter spp.
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Which cephalosporins are able to treat bugs in the CSF?
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3rd and 4th generation cephalosporins are able to kill bugs int he CSF.
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What are the 1st, 2nd, 3rd and 4th generation cephalosporins used for clinically?
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1st generation: surgical prophylaxis
2nd gen: sinusitis, otitis media, URI,LRI, 3rd gen: ceftazidime used if pseudomonas is suspected or present. Ceftriaxone is used for uncomplicated gonorrhea, CAP (community aquired pneumonia), PRSP (penicillin resistant strep pneumoniae) and viridans strep endocarditis 4th gen: used where pseudomonas aeruginosa is present |
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What are the adverse effects of cephalosporins?
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Hypersensitivity-5% overall. Most people are cross-reactive with penicillins (5-15%). If it is an IgE mediated reaction avoid cephalosporins.
MTT Side chain: hypoprothrombinemia (bleeding); due to reduction in vit-K producing bacteria in gut. Hematologic: leukopenia and thrombocytopenia. GI: C. diff colitis. |
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Name the four carbapenems
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Imipenem, meropenem, ertapenem (no good vs pseudomonas aeruginosa) and doripenem.
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How do the carbapenems work?
How do bacteria gain resistance against them? |
They act in the same way as the others do - by inhibiting cell wall synthesis by binding to an inhibiting PBPs (primarily PBP-2). They are able to easily penetrate bacterial cell walls because they are small..
Resistance is the same as all the others (beta lactamase production, decreased permeability and alteration to the PBPs) |
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What are carbapenems used against?
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Carbapenemsare the most broad spectrum agents available and have activity against gram-positive and gram neagative aerobes AND anaerobes. Imipenem and doripenem are the best.. however they will NOT kill any resistant bacteria or S. maltophilia or Nocardia (use Bactrim on those two)
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Imipenem is comarketed with what, and why?
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Imipenem undergoes hydrolysis by a dihydropeptidase (DHP) in the renal brush border to a nephrotoxic metabolite. When imipenem is given with cilastatin (a DHP inhibitor) this problem is avoided.
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How long are carbapenem half-lives?
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Ertapenem has the longest half-life (4 hours) the others are shorter
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What carbapenem do you NOT give for pseudomonas aeruginosa?
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Ertapenem
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What do you treat SPICE infections with?
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Carbapenems!
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What are the adverse effects for carbapenems?
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3% incidence of hypersensitivity... rash, itching, GI problems.
CNS PROBLEMS: can cause seizures if there is: a pre-existing CNS disorder, a high dose given, renal insufficiency |
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What are the monobactams?
And how are they given? |
Theres only one... Aztreonam. It is only available IV
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How do monobactams work?
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They inhibit cell wall synthesis by binding to PBP-3 which is found ONLY in gram-negative aerobes... which are basically HENPEK + Pseudomonas aeruginosa
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What are the drugs used to treat pseudomonas aeruginosa?
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Ceftazidime, imipenem, doripenem, meropenem, aztreonam
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