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96 Cards in this Set

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What is the mechanism by which penicillin works?
Inhibits cell wall in GROWING bacteria by alternating N-acetylglucosamine in linear form with N-acetylmuramic acid. The chains are cross linked by peptides.

They also bind to PBPs that function in cell wall synthesis. Transpeptidase cross links murein and carboxypeptidases modify the murein. Penicillins covalently bond with the enzymes to inhibit cross linking.
Where is the cross link located in gram (+) bacteria?
Thru a peptide between the amino group of lysine and the terminal carboxyl group of a D-alanine residue.
Where is the cross link located in gram (-) bacteria?
Between diaminopimelic acid and D-alanine.
What are 3 ways in which bacteria resist penicillins?
With B-lactamase

Altering the target by decreasing the binding affinity of the antibiotic for PBPs.

Decreasing permeability (porin loss/mutation).
Which 2 pathogens are resitant because of altering the antibiotic target?
MRSA, pen-resistant Strept. pneumoniae
What is an example of a pathogen that resists via porin loss/mutation?
Pseudomonas against imipenems.
What are symptoms of pseudomonas?
fever and worsening pneumonia
What are the 2 natural penicillins?
G and V
What are the semi-synthetic penicillins?
Penicillinase resistant (against Staph aureus).

Aminopenicillins (Ampicillin and Amoxicillin).

Carboxy and extended spectrum ureidopenicillins (against gram negatives, like Pseudomonas)
How does bacteria resist Pen. G?
With beta lactamase
What is the spectrum for Pen. G?
Aerobic gram (+) cocci

Gram (-) cocci, like Neisseria
meningiditis. 40% of gonorrhea are resistant.

Anaerobic cocci and bacilli, like Listeria or Clostridia.

Spirochetes, like Syphilis.
NOT gram (-) bacilli
PENICILLIN G
IV, IM, or oral?
Long or short half life?
Distribution?
Elimination?
IV or IM because it is acid labile.
Short half life--given 4 times a day

Well distributed to lung, liver, kidney, muscle, and bone. Also to the CSF when inflamed.

Poor distribution intracellularly, to the eye, prostrate, and brain without inflammation.

Renal tubular cells...reduce dose for dialysis patients and with renal problems (other than Na type).
What is the spectrum for Pen. V?
Similar to Pen. G (gram + cocci, gram (-) cocci, anaerobes, and spirochetes. Less active against Haemophilis, Neisseria, and enterics.
PENICILLIN V
IV, IM, or oral?
Distribution?
Elimination?
Oral
Lower serum levels than Pen. G
Renal elimination
What are common uses for
Pen. V?
Mild oral problems (abscessed tooth for example), pharyngeal problems, skin infections.
What are examples of penicillinase-resistant penicillins? Why were they created?
Methicillin, nafcillin (IV), oxacillin (IV/oral), cloxacillin (PO), and dicolxacin (PO). These are used against penicillinase producing staphylococci.
What is the spectrum for peniccilinase-resitant penicillins?
Gram (+) and bacilli
NOT Listeria, enterococcus, MRSA, cephalosporins.
Elimination of nafcillin?
Elimination of dicloxacillin?
Liver and a little by kidney
Renal
Clinical uses for Nafcillin?
Penicillinase-producing S. aureus.
Clinical uses for Dicloxacillin?
Mild staph infections in skin and tissues (paronychia, furuncles, and cellulitis), and Strep.
What is special about aminopenicillins?

What drugs fall into this group?
Increased permeability towards gram (-) bacteria.
And they are inactivated by beta lactamases.

Ampicillin and Amoxicillin
What is the spectrum for aminopenicillins?
Gram (+)--slightly wose against Strept.
Slightly better against L. monocytogenes and enterococci. Use Ampicillin for these 2 diseases.

Gram (-) but not very effective because most are resistant.

Anaerobes but not very effective because most are resistant.

Amoxicillin for sinusitis, bronchitis, otitis, and CAP.

*Usually given with aminoglycosides for synergy.
AMINOPENICILLINS
IV, IM, or oral?
Distribution?
Elimination?
Side effects?
Oral but oral is more effective in Amoxicillin.
Similar to Pen. G--well distributed to the lungs, kidneys, muscle, bone, and CSF when there's inflammation, low intracellular levels, poor entry into the eye, prostrate, and brain when there is no inflamm.

A maculopapular rash that can be confused with an allergy. It can exist in pts with mono, chronic lymocytic leukemia, and pts on allopurinol.
What are the two carboxypenicillinases?

Uses?
Carbenicillin and Ticarcillin
Carbenicillin is no longer used and Ticarcillin is used in conjugation with beta lactamase inhibitors.
What are the two ureidopenicillins?
Mezlocillin and Piperacillin

*These carry lower sodium loads, which can result in heart failure for the elderly.
What is the spectrum for Pipercillin?
Aerobic gram (+), like enterococci
Aerobic gram (-), the best against these! Such as Neisseria, Haemophilus, Enterobacteriaceae, and Pseudomonas.

Anaerobes, but only when combined with something else. It alone is inferior to Metronizadole or clindamycin against anaerobes.

Synergy with Pipercillin is good against Psedumonas, enterobacteriaceae, and Enterococcus.
*Inactivated by beta lactamases.
PIPERCILLIN
IV, IM, or oral?
Distribution?
Elimination?
IV and IM
Well distributed to the lungs, liver, kidneys, muscle, bone, and CSF when there is inflamm. Low intracellular levels and poor entry into the the eyes, prostrate, and brain when there is no inflamm.

Glomerular filtration and tubular secretion. Dose adjustmants must be made due to increases in biliary excretion which can cause gallbladder problems.
What are the clinical uses for Pipercillin?
Bacterermia, pneumonia, endocarditis, osteomyelitis, UTI, pelvic and intra-abdominal infections, and for gram (-) infections.
What are the adverse effects of any beta lactam?
Anaphylaxis (mostly with Pen.G, early uritcaria (mostly with Pen. G), hemolytic anemia (mostly with Pen.G), serum sickness (mostly with Pen. G), delayed hypersensitivity/contact dermatitis (mostly with Ampicillin), skin rash-fever-late urticaria (mostly with Amp.), diarrhea-enterocolitis (mostly with Amp).
What are the adverse effect of penicillins?
Neutropenia (Pen. G, Nafcillin, Oxacillin, Pipercillin), platelet dysfunction (ticarillin), increased tranaminase which can lead to hepatotoxicity (oxa and naf), too much sodium (tic), acute hyperkalemia (pen G), seizures (pen G), bazzare sensations (pen), intersitial nephritis (methicillin)
Which penicillins are hydrolyzed by Staph. penicillinase?

Which are not hydrolyzed?
Natural penicillins, amino-, carboxy-, and ureido-

Naf-, oxa-, and dicloxacillin
How do Penicillin/beta lactamase inhibitors work?
They bind and inactivate beta lactamases, protecting their partner from hydrolysis. Also, they potentiate the activity of their partner by binding directly to bacterial PBPs.
What are three penicillin/beta lactamase inhibitors?
Clavulanic acid, sulbactam, and tazobactum.
What is the spectrum for penicillin/beta lactamase inhibitors?
Staph aureus, anaerobes, N. gonorrhea, H. influenza, Moraxella catarrhalis, E-coli, Klebsiella, Proteus, and Providencia.

NOT Enterobacter, Citrobacter, Serratia, and Pseudomonas.
What is timentin?
What is its spectrum?
A combination drug of clavulante and ticarcillin.

It is used against polymicrobial infections and Stenotrophomonas.
What is Augmentin?
What is its spectrum?
A combination of Amoxicillin and clavulanate. The only oral combo.

It is used against otitis, sinusitis, lower resp. infections, UTI, skin and soft tissue, human and animal bites because of its activity against S. aureus oral anaerobes.
What is Unasyn?
A combination of ampicillin and sublactam.
What is Zosyn?
A combination of piperacillin and tazobactum. Uses are similar to Timentin but Zosyn is more potent: polymicrobial infections, stenotophomonas maltophilia. Also used against Enterobacteriacea.

NOT pipercillin-resistant Pseudomonas.
There are two pathogen types that are NOT inhibited by B-lactamase inhibitors. What are they?
MRSA and resistant pneumococcus.
What is the structure of penicillin?
Thiazolidine and beta-lactam rings.
What is the structure of a cephalosporin?
B-lactam dishydrotiazine rings. Changes at position 3 causes metabolic/pharmokinetic changes. Changes at position 7 causes antimicrobial changes.
What are the 1st generation cephalo?
Cefazolin and cephalexin
What are the 2nd generation cephalo?
Cefurocime and cefoxitin
What is one use for cefuroxime?
Influenza
(A third generation cephalosporin)
What is a side effect of cefoperazone?
It inhibits vitamin K.
Describe the pattern of cephalosporins' action against gram (-) and gram (+)
Each generation has enhanced gram (-) activity compared to the preceding generation, and less gram (+) activity. Exceptions are cefepime and ceftaroline.
Are earlier or later cephalos preferred?
Earlier because they cost less.
Which cephalosporin has activity vs. gram (-) gut anaerobes?
Cephamycins (2nd generation)
Do any of the cephalosporins have good activity against enterococci?
No.
Which two cephalosporins are active against Pseudomonas?
Ceftazidime and cefepime
What is the spectrum for Cefazolin?
S. aureus (but not MRSA), streptococci.

NOT influenza, catarrhalis, enterococcus, or anaerobes.
How is Cefazolin eliminated?
By the kidneys. All cephalosporins do except for ceftriaxone and cefoperazone.
Is killing concentration dependent for Cefazolin?

Is there a postantibiotic effect?
Cefazolin is not concentration dependent. And there is no significant post-antibiotic effect.
Are aminoglycosides concentration dependent?
Yes.
Where does Cefazolin go to in the body?
Everywhere except for the CSF.
What clinical reasons is Cefazoin good for?
skin and soft tissue infections, surgical prophylaxis--for appendix and bowel surgeries.

NOT for sinusitis, otitis, and pneumonia.
What is the spectrum for Cephalexin?
Penicillinases, S. aureus (not MRSA), streptococcus.

NOT for H. inflluenzae, catarrhalis, enterococcus, and anaerobes.
What clinical reasons is Cephalexin good for?
Minor infections like pharyngitis, cellulitis, furuncles.

NOT for Pasturella multocida (animal bites).
What is the spectrum for Ceforxime?
Streptococci, S. aureus, B-lactamases, influenza, gonorrhea, cattarhalis, E-coli, mirabilis, Klebsiella, citrobacter, and Morganella.

NOT for proteus vulgaris, serratia, and providencia. Also, not for Legionella, mycoplasma, anaerobes, or Pseudomonas
What is the body distrubtion for Ceforxime?
Tissue and fluid, including CSF. However its CSF activity is not good as the 3rd generation.
What clinical uses does Ceforxime have?
Community-acquired pneumonia, epiglottis, sinusitis, bacteremia, soft tissue infection, and UTI.
What is the spectrum for cefaclor?
(a second-generation cepalosporin)
More active against H. influenze and M. catarrhalis than the 1st generation.
What is cefaclor used for?
Minor respiratory infections although not as good as cefuroxime. Smells good for kids. :)
What is the spectrum of Cephamycin/Cefoxine?
Gram (-) and gram (+). Its gram (+) action is not as good as the first generations. Not very active again H. influenzae. VERY GOOD at E.coli, Klebsiella, and Proteus. It is also the ONLY one that is very good against gram (-) anaerobes. Used in gut and appendicitis.

NOT Pseudomonas
Where is the body distribution for Cephamycin?
Very wide except in the prostrate, vitreous humor, and CSF.
What are the clinical uses for Cephamycin?
Intrabdominal, pelvic, ulcers, tissue infection (for all anaerobes), pelvic inflamm. disease (when combined with doxycycline).
What is the spectrum for Ceftriaxone?
Gram (+) against pneumoniae, S. pyrogenes, Staph. auerus, enterococci, and Listeria.

Gram (-) Neisseria, H. influenzae, E. coli, P. mirabilis, Klebsiella, Pseudomonas, and Stenotrophomonas.
NOT fragilis and MRSA
What is the elimination method for Cetriaxone?

Distribution?
Renal and biliary

Very wide. Includes CSF, as do all 3rd generation cephalosporins.
What are the uses for Ceftriaxone?
Nosocomial infections from gram negatives--pneumonia, wounds, UTI, septic arthritis. Also, bacterial meningitis, gonorrhea, and outpatient cases (like Lyme Disease).
What are the uses for ceftriaxone?
Severe nosocomial infections from gram (-) bacteria--pneumonia, wounds, complicated UTI, septic arthritis. Also meningitis, gonorrhea, late therapy for Lyme disease.
(A third generation cephalosporin)
What is the specturm of cefixime?
Similar to ceftriaxone--Severe nosocomial infections from gram (-) bacteria--pneumonia, wounds, complicated UTI, septic arthritis. Also meningitis, gonorrhea, late therapy for Lyme disease. However, not as good for S. aureus. Can be used for penicillinase strains of gonorrhea and is 2nd line for sinusitis and otitis.
What is the spectrum for ceftazidime?
Referred to as anti-pseudo ceftazimine. It is good for empiric treatment of febrile neutropenia that could be caused by Pseudomonas. It has poor anti-Staph capability.
Does ceftazidime go to the CSF?
Yes.
What is the spectrum for cefepime?
Broader spectrum because of its resistance to beta-lactamase (-) bacteria. Excellent for Staph and Strep., Pseudomonas, Neisseria, influenza, E. coli, mirabilis, Klebsiella, and other Enterobacteriaceae. Also against Pseudomonas.

NOT listeria, MRSA, gut anaerobes.
Does cefepime achieve good levels in the CSF?
Yes.
What is cefepime used for?
Nosocomial pneumonias and in febrile situations.
What is ceftaroline used for?
Excellent gram (+) activity, MRSA.
Good gram (-) activity, influenza, E. coli, Salmonella, Citrobacter freundii, Morganella, Proteus, and Klebsiella.

NOT P.aeruginosa, E. colacae, and Providencia
What is ceftaroline resistant to?
Amp C beta-lactamases, ESBLs. However it does work against MRSA. This limits its ability to work against healthcare-assoc-pneumonia.
What are some general adverse reactions to cephalosporins?
Hypersensitivity (with eosinophilia), Hematologic (with neutropenia, and an increase in leukocytes), Hypoprothrombinemia, GI problems.
What are some exceptions to each generation adding some gram (+) activity and losing gram (-) activity?
Cefepime retains gram (+) activity.
Which cephalosporin is active against gram (-) intra-abdominal anaerobes?
Cefoxitin
Which generations have good CSF levels?
3rd and 4th.
Which two cephalosporins are active against Pseudomonas?
Ceftazidime and Cefepime.
What is the structure of aztreonam?
A monocyclic beta-lactam.
What is the spectrum of Aztreonam?
Not much activity versus gram (+) and anaerobes. Works against Pseudomonas (aerobic neg.) Usually not hyrdolyzed by B-lactamases. Also used for nosocomial gram (-) infections.

NOT active against S. maltophilia and Acinenobacter.
How is Aztreonam administered?
IV only.
How is Aztreonam eliminated?
Renal.
What are the adverse reactions to Aztreonam?
Well it doesn't cross-react with penicillin-or cephalospoin-allergy. Can cause a skin rash with mild transaminase elevation.
What are the carbapenems?
Imipenem, meropenem, ertapenem, and doripemem
What is the spectrum for Carbapenems?
Very broad spectrum. Not hydrolyzed by most beta-lactamases, works against gram (+)--except for MRSA, gram (-), and anaerobes.
What can make resistance possible in the carbapenems?
Loss or mutation of the outer membrane that decreases the amount of porins, and carbanemases.
How is imipenem distributed in the body?
Widely distributed, except in the CSF and biliary tract.
What are adverse effects of imipenem?
Cross allergy with other B-lactams, mild transaminas increase, and seizures.
Which carbapenem is most active versus Pseudomonas?
Doripenem
What are carbapenems used for?
Febrile neutropenia, mixed infections, intra-abdominal infections, diabetic feet.

Do not use it alone for Pseudomonas due to increase in Pseudomonas resistance.
Which Beta-lactam shows no cross-allergy with other beta-lactams?
Atreonam.