Term
| Who accidentally discovered the gram staining technique? |
|
Definition
|
|
Term
What type of bacteria are:
Strep pneumoniae
S. pyogenes (group A)
Staph. aureus
-MS: methicillin sensitive
-MR: methicillin resistant |
|
Definition
|
|
Term
What type of bacteria are the following:
-Clostridium sp.
-Listeria
-Bacillus anthracis |
|
Definition
|
|
Term
What type of bacteria are the following:
neisseria meningitidis
Moraxella catarrhalis |
|
Definition
|
|
Term
What type of bacteria are the following:
enteric pathogens
-proteus sp.
-e. coli
-klebsiella sp
(PEK group: community acquired)
-enterobactere
-serratia
bacteroides
(nosocomial)
pulmonary pathogens:
-h. influenzae
highly resistant
-p. aeruginosa
-acinetobactor |
|
Definition
|
|
Term
| What is the smallest free living organism, with *no cell wall* that has an incubation period of 3 weeks? |
|
Definition
|
|
Term
| What is an *intracellular* g- parasite? |
|
Definition
| chlamydophyla pneumoniae, related to chlamydia |
|
|
Term
| What is a g- bacteria that exists in aquatic reservoirs and is hard to visualize or grow on medium? |
|
Definition
|
|
Term
| These antibacterial agents inhibit cell wall synthesis. |
|
Definition
β-lactams
-penicillins
-cephalosporins
-monobactams
-carbapenems
bacitran
daptomycin
vancomycin |
|
|
Term
| What class of antibiotics inhibits bacterial DNA gyrase? |
|
Definition
|
|
Term
| Which antibiotics inhibit bacterial folic acid synthesis? |
|
Definition
| trimethoprim-sulfamethoxazole |
|
|
Term
| Which antibacterial agents inhibit bacterial protein synthesis? |
|
Definition
macrolides and ketolides
tetracyclines
aminoglycosides
clindamycin
quinupristin-dalfopristin
linezolid
mupriocin |
|
|
Term
| Which antibiotics are classified as antitubercular agents? |
|
Definition
| isoniazid rifampin pyrazinamide ethambutol |
|
|
Term
| Imipenem-clilistatin, meropenem, and ertapenem belong to which drug class? |
|
Definition
| Carbapenems: inhibitors of bacterial cell wall synthesis: β-lactam antibiotics |
|
|
Term
| Aztreonam belongs to which class of antibiotics? |
|
Definition
| Monobactams: inhibitors of bacterial cell wall synthesis: β-lactam antibiotics |
|
|
Term
| What class of antibacterial agents is divided into 1st-4th generation? |
|
Definition
| Cephalosporins: inhibitors of bacterial cell wall synthesis: β-lactam antibiotics |
|
|
Term
| What are 5 classifications of penicillins? |
|
Definition
Natural penicillins,
Aminopenicillins,
Extended-spectrum penicillins,
β-lactamase inhibitor combinations ,
penicillinase-resistant penicillins |
|
|
Term
| What is the MOA of penicillins? |
|
Definition
| bind to penicillin-binding proteins (PBPs) on cell wall to inhibit further synthesis |
|
|
Term
| How do bacteria become resistant to penicillin? |
|
Definition
-By producing β-lactamase enzymes that destroy β-lactam ring of penicillin molecule
-mutation of PBP to prevent binding by penicillin |
|
|
Term
| On what does the activity of β-lactam antibiotics depend? |
|
Definition
| Activity depends on affinity to PBPs or degree of resistance to β-lactamase enzymes |
|
|
Term
How do the following bacteria produce resistance to β-lactam antibiotics:
staph
haemophilus
enterobacter |
|
Definition
|
|
Term
How do the following bacteria produce resistance to β-lactam antibiotics:
MRSA
penicillin-resistant pneumococcus |
|
Definition
| mutation of PBP to prevent binding by penicillin |
|
|
Term
| Do penicillins have a long or short half life? |
|
Definition
| relatively short half-lives |
|
|
Term
| How are most penicillins eliminated? |
|
Definition
| most eliminated by the kidney unchanged |
|
|
Term
| What are 3 immediate hsn rxns? |
|
Definition
anaphylaxis
urticaria
edema |
|
|
Term
| What is an example of an accelerated hsn rxn? |
|
Definition
|
|
Term
| What are 3 delayed hsn rxns? |
|
Definition
| days to weeks: rash, fever, serum sickness |
|
|
Term
| Describe cross sensitivity in relation to penicillins. |
|
Definition
| Cross sensitivity exists among all penicillins. Avoid if history of immediate or accelerated rxn w/any penicillin group. |
|
|
Term
| What is the history of penicillin? |
|
Definition
| Isolated from Penicillium in Eng, and secretly shipped to US just before WWII. 1st used to tx burn victims of Coconut Grove fire in Boston. |
|
|
Term
| Against what was penicillin originally active? |
|
Definition
| all staph and strep species |
|
|
Term
| How and when did staph develop resistance to natural penicillin? |
|
Definition
| by the early 50's, staph had aquired a gene that produces penicillinase |
|
|
Term
| How many strains of staph exist today that are sensitive to penicillin? |
|
Definition
|
|
Term
| What was the 1st penicillin? |
|
Definition
|
|
Term
| How is penicillin G administered? |
|
Definition
| very acid-labile and only given IV |
|
|
Term
| What is the T1/2 of penicillin G? |
|
Definition
|
|
Term
|
Definition
| units (1 mil units = 0.6 gm) |
|
|
Term
| How is procaine penicillin G administered? |
|
Definition
| suspension given IM that lasts from 1-4 days depending on dose |
|
|
Term
| How is benzathine penicillin G administered? |
|
Definition
| suspension given IM that can last up to several weeks |
|
|
Term
| How is penicillin V administered? |
|
Definition
| oral form of penicillin that is more acid-stable |
|
|
Term
| When are natural penicillins (G and V) indicated? |
|
Definition
Use: narrow spectrum antibiotic active against
strep (pyogenes, pneumoniae)
neisseria meningitidis
clostridium sp.
treponema pallidum (syphilis) |
|
|
Term
| What was the first of all semisynthetic penicillins, which are produced from 6-aminopenicillinamic acid? |
|
Definition
|
|
Term
| How is ampicillin administered? |
|
Definition
|
|
Term
| What is the T1/2 of ampicillin? |
|
Definition
| 80 min, so must be given qid |
|
|
Term
| What is the *most common antibiotic prescribed*? |
|
Definition
|
|
Term
| What is the oral equivalent of ampicillin b/c of better absorption? |
|
Definition
|
|
Term
| How frequently is amoxicillin administered? |
|
Definition
|
|
Term
| When are higher doses of amoxicillin indicated? |
|
Definition
| used if suspicion of penicillin-resistant pneumococcus |
|
|
Term
| What is an idiosyncratic rxn produced by either ampicillin or amoxicillin? |
|
Definition
| *ampicillin rash* with either product- up to 10% of individulas |
|
|
Term
| What is the incidence of an ampicillin rash if mononucleosis is present or pt is taking allopurinol for gout? |
|
Definition
|
|
Term
| What are some uses for aminopenicillins? |
|
Definition
active against common URI pathogens:
-s. pyogenes
-s. pneumonia (most strains)
-h. influenza (most strains)
some activity against enterococcus and common community g- bacteria
-e. coli
-proteus sp.
*have no activity against staph* |
|
|
Term
| What is a drug with no activity against staph? |
|
Definition
aminopenicillins,
extended spectrum penicillins |
|
|
Term
| Against what bacteria do aminopenicillins and extended-spectrum penicillins have no activity? |
|
Definition
|
|
Term
| Do aminopenicillins and extended-spectrum penicillins have activity against staph? |
|
Definition
| *Have no activity against staph* |
|
|
Term
| What are extended-spectrum penicillins also known as? |
|
Definition
| anti-pseudomonal penicillins |
|
|
Term
| What is the most common agent in the extended-spectrum class of penicillins? |
|
Definition
|
|
Term
| How is piperacillin administered? |
|
Definition
|
|
Term
| How is piperacillin (pipracil) usually used? |
|
Definition
| usually used in combination with tazobactam (Zosyn) |
|
|
Term
| How is piperacillin (pipracil) excreted |
|
Definition
| excreted via the biliary tract |
|
|
Term
| To what class to the antibiotic agents carbenicillin, ticarcillin, and mezlocillin belong, and how frequently are they used? |
|
Definition
| extended-spectrum penicillins, older agents- rarely used now |
|
|
Term
| What are 2 adverse effects of extended-spectrum penicillins? |
|
Definition
Na+ overload with high doses
Thrombocytopenia with high doses |
|
|
Term
| For what conditions are extended-spectrum penicillins indicated? |
|
Definition
extended activity against g- bacteria
p. aeruginosa activity
-combine w/aminioglycoside antibiotic for serious p. aeruginosa infections
bacteremia, pneumonia, neutropenic fever
retains activity against enterococcus
*no activity against staph* |
|
|
Term
| What are 3 examples of β-lactam/Penicillin combinations? |
|
Definition
Clavulanic acid + amoxicillin = Augmentin
Sulbactam + ampicillin = Unsyn
Tazobactam + piperacillin = Zosyn |
|
|
Term
| When is Augmentin indicated? |
|
Definition
(now generic)
for diabetic foot wounds, bites, Staph infections |
|
|
Term
|
Definition
*Most widely used IV antibiotic in hospitals*
Active against most g+, g-, and anaerobic bacteria |
|
|
Term
| What is the *most widely used IV antibiotic in hospitals*? |
|
Definition
|
|
Term
| What is the MOA of β-lactamase inhibitors? |
|
Definition
| preferentially combine with β-lactamase enzymes produced by bacteria and inactivate them |
|
|
Term
| How do β-lactamase inhibitor/penicillin combinations work? |
|
Definition
increases activity against staph, g-, and anaerobic bacteria
however, high inoculum effect may neutralize activity |
|
|
Term
| Do β-lactamase inhibitor/penicillin combinations increase activity against bacteria that are resistant b/c of altered PBPs (ie MRSA)? |
|
Definition
|
|
Term
| How does combining a β-lactamase inhibitor to penicillin affect the kinetics and adverse affects of penicillin? |
|
Definition
| same kinetics, adverse effects, etc as penicillins used alone |
|
|
Term
| What is a class of semisynthetic penilillins specifically developed to tx staph resistant to penicillins? |
|
Definition
| penicillinase-resistant penicillins |
|
|
Term
| What was the first penicillinase-resistant penicillin? |
|
Definition
| *methicillin*, but it was removed from the market secondary to cases of interstital nephritis. |
|
|
Term
| Methicillin was introduced in 1960. When did the 1st MRSA strain appear? |
|
Definition
|
|
Term
| What gene confers resistance to MRSA? |
|
Definition
| *mecA* gene codes for new PBP2a |
|
|
Term
| What percentage of staph aureus in hospitals are methicillin-resistant? |
|
Definition
|
|
Term
| How is nafcillin administered? |
|
Definition
only used IV
must give 4-6x/day |
|
|
Term
| What is an adverse rxn of nafcillin? |
|
Definition
| can cause severe phlebitis at IV site |
|
|
Term
| What medication is the oral equivalent of nafcillin? |
|
Definition
|
|
Term
| Which 2 medications are the best choice for *susceptible* staph? |
|
Definition
|
|
Term
| What group of drugs is similar to penicillins in that they share a β-lactam ring, but is more stable than the β-lactamases? |
|
Definition
|
|
Term
| From what are cephalosporins derived? |
|
Definition
| semisynthetic drugs derived from cephalosporium |
|
|
Term
| What is the MOA of cephalosporins? |
|
Definition
| bind to PBPs on cell wall to inhibit further synthesis |
|
|
Term
| What is the mechanism of resistance of bacteria against cephalosporins? |
|
Definition
| bacteria producing a variety of β-lactamase enzymes that destroy β-lactam ring of molecules |
|
|
Term
| Against what bacteria do cephalosporins have NO activity? |
|
Definition
| MRSA enterococcus sp listeria |
|
|
Term
| Into how many groups are cephalosporins classified? |
|
Definition
4 groups based on spectrum of activity:
with each succeeding generation more g- activity but less g+ activity |
|
|
Term
| What are the T1/2 of cephalosporins? |
|
Definition
| vary from short to very long |
|
|
Term
| What are some important adverse rxns of cephalosporins? |
|
Definition
-hsn rxns less common than penicillins
-cross sensitivity with penicillins is minimal unless hx of anaphylactic rxn w/penicillins
-bacterial resistance tends to develop quickly w/use (reason why so many cephalosporins were developed) |
|
|
Term
| What are 4 1st generation cephalosporins and how are they administered?? |
|
Definition
cefazolin (kefzol)- IV
cephalexin (keflex)- oral
cephradine (velocef)- oral
cefadroxil (duracef)- oral |
|
|
Term
| How frequently is cefazolin (kefzol) administered? |
|
Definition
| IV- usually given every 8 hrs |
|
|
Term
| What is the half lives for cephalexin (keflex) and cefadroxil (duracef)? |
|
Definition
cephalexin (keflex)-short T1/2
cefadroxil (duracef)- long T1/2 |
|
|
Term
| When are 1st generation cephalosporins indicated? |
|
Definition
-active against strep sp and MSSA
-also active against e.coli and klebsiella sp.
-cefazolin (Kefzol) widely used in hospital for staph and strep infections
-cephalexin (Keflex) widley used in community for staph and strep infections |
|
|
Term
| What are 5 2nd generation cephalosporins and how are they administered? |
|
Definition
| ceufuroxime (ceftin)- IV cefotetan and cefoxitin- IV cefuroxime- oral (can switch from IV) cefaclor-oral cefprozil-oral |
|
|
Term
| When are 2nd generation cephalosporins indicated? |
|
Definition
-increased activity against g-bacteria including:
-klebsiella pneumonia
-h. influenzae
-m. catarrhalis
-for community-acquired pneumonia and more resistant URIs such as otitis media
-cefuroxime (cefitin) for URI's
-cefotetan and cefoxitin for abnominal and gynecologic infections b/c of increased anaerobic activity |
|
|
Term
| How are 3rd generation cephalosporins different in active v. oral forms? |
|
Definition
| IV forms are much more active than oral forms |
|
|
Term
| What are 5 examples of 3rd generation cephalosporins and how are they administered? |
|
Definition
cefotrexamine (claforan)- IV
cefitriaxone (rocephin)- IV
ceftazidime (fortaz)- IV
cefixime (suprax)- oral
cefpodoxime (vantin)- oral |
|
|
Term
| What are the T1/2s of cefotaxime (claforan) and cefitriaxone (rocephin)? |
|
Definition
cefotaxime (claforan)- short T1/2
Ceftriaxone (9rocephin)- long T1/2, given qd IM/IV |
|
|
Term
| When are 3rd generation cephalosporins indicated? |
|
Definition
-IV forms with wide range of activity against g- and g+
-Used for nosocomial infections, pneumonia, meningitis, advanced lyme disease
-ceftazidime only 3rd gen w/activity against pseudomonas (useful alt to piperacillin)
-no activity against anaerobic bact |
|
|
Term
| What is a 4th gen cephalosporin and how is it administered? |
|
Definition
| cefepime (maxipime) only given IV |
|
|
Term
| When is cefepime (maxipime) indicated? |
|
Definition
-more resistant to chromosomal β-lactamase enzymes (produced by enterobacter sp)
-good activity against enterobacteriaceae and pseudomonas aeruginosa
-unlike ceftazidime, also good activity against penicillin-resistant strep pneumoniae |
|
|
Term
| What is an example of a monobactam and how is it administered? |
|
Definition
| Aztreonam (azectam)- only given IV |
|
|
Term
| What drug has a *monocyclic* β-lactam ring? |
|
Definition
|
|
Term
| What is a drug with no cross sensitivity in pts with a hx of severe penicillin or cephalosporin hsn rxns? |
|
Definition
|
|
Term
| What medication has similar activity to ceftazidime with activity against many g- as well as pseudomonas? |
|
Definition
|
|
Term
| What is the activity of Aztreonam (Azactam) against g- and g+? |
|
Definition
active against many g-
has no activity against g+ |
|
|
Term
| What medication is *used for pts with β-lactam allergies*? |
|
Definition
|
|
Term
| Which is the broadest spectrum of antibacterial drugs available? |
|
Definition
|
|
Term
| What are 3 examples of Carbapenems and how are they administered? |
|
Definition
Imipenem-cilistatin (primaxin)- IV
meropenem (Merrem)- IV
ertapenem (invanz)- IV |
|
|
Term
| What helps increase the T1/2 of Imipenem-cilistatin (primaxin) |
|
Definition
cilistatin inhibits enzyme that hydrolyzes imipenem in kidney.
need to give every 8 hrs |
|
|
Term
| Which of the carbapenems have the longest T1/2? |
|
Definition
| ertapenem (invanz)- given qd |
|
|
Term
| To what are carbapenems structurally related? |
|
Definition
| other β-lactam antibiotics |
|
|
