Cell Wall synthesis inhibs-Antimicrobials

Question 1

What are the 4 main categories of antimicrobial agents that affect cell wall synthesis?

Answer 1

1-Penicillins
2-Cephalosporins
3-Carbapenes
4-Monobactams

Question 2

What are 3 B-lactamas inhibitors?

Answer 2

1-Clavulanic acid (with amoxicillin=augmentin)
2-Sulbactam (with amp=unasyn)
3-Tazobactam(with piperacillin=zosyn)

Question 3

Which type of antimicrobial resembles the D-Ala-D-Ala end of the peptide that serves as a substrate for transpeptidase enzymes?

Answer 3

B-lactams

*are bacteriocidal

Question 4

Which enzymes crosslink adjacent glycerin chains of peptidoglycan precursors to form bacterial cell walls?

Answer 4

Transpeptidase

*B-lactams disrupt this function by inhibiting transpeptidation.

Question 5

What are five categories or B-lactam antimicrobials?

Answer 5

1-Natural penicillins
2-Aminopenicillins (extended spectrum)
3-Penicillinase-resistant penicillins (anti-staphylococccal)
4-Anti-pseudomonal penicillin
5-Cephalosporins

Question 6

Benzathine penicillin is an example of what type of natural penicillin that is active against Gram + cocci, is narrow spectrum, and rapidly hydrolyzed by penicillinase enzymes?

Answer 6

Penicillin G

Question 7

Which type of Natural penicillin is an acid stable analogue to Pen G, is orally active and has the same spectrum as Pen G, but less active?

Answer 7

Penicillin V

Question 8

Ampicillin and amoxicillin are examples of what type of B-lactam?

Answer 8

Aminopenicillins

*have better Gram (-) coverage than Pen G or V

Question 9

What are two examples of drugs that amoxicillin or ampicillin have a B-lactamase inhibitor combined?

Answer 9

Augmentin (amoxicillin + clavulonate)

Unasyn (Ampicillin + sublactam)

Question 10

What inhibits renal tubular secretion of methotrexate and results in high serum levels of methotrexate?

Answer 10

Amoxicillin (drug of choice for infective endocarditis)

*Amp has higher oral absorption, Cpmax values and longer half life than Amo

Question 11

Methicillin, nafcillin, oxacillin and dicloxacillin are less potent than Pen G and are used to treat S aureus, S epidermis that produce what?

Answer 11

Pencillinase (these are penicillinase resistant penicillins)

Question 12

Which two penicillinase resistant penicillins undergo biliary, not renal, excretion?

Answer 12

Oxacillin and dicloxacillin

Question 13

What drug is used for serious S. Aureus infections (Non-MRSA)?

Answer 13

Nafcillin (Use Naf for Staph)

Question 14

Which drug is combined with some antibiotics to increase their serum levels and prolong half lives by inhibiting excretion of such drugs?

Answer 14

Probenecid

Question 15

Indanyl carbenicillin and ticarcillin are carboxypenicillins that have wider coverage of Gram (-) and are part of what group of B-lactams?

Answer 15

Anti-pseudomonal penicillins

*Ticarcillin 2-4 x’s more active than indanyl and used for P. aeruginosa. Was replaced by Timentin (ticarcillin + clavulonate)

Question 16

What are the 3 subcategories of Anti-pseudonomal penicillins?

Answer 16

1-Carboxypenicillins (indanyl carbenicillin, ticarcillin)
2-Ureidopenicillins (Piperacillin, broadest spectrum penicillin)
3-Monobactams (Aztreonam)

Question 17

Great for patients with IgI-mediated penicillin allergy, which anti-pseudonomal penicillin is resistant to some B-lactamases?

Answer 17

Aztreomnam (IV)

Question 18

What are the 3 types of allergic reactions to penicillins/b-lactams?

Answer 18

1-Immediate (within 30 minutes, anaphylaxis, IgE mediated)
2-Accelrated (30 min-48 hr)
3-Delayed onset (longer than 2 days. 80-90% of penicillins are this, rashes)

Question 19

Large doses of Pen G may produce lethargy, confusion, twitching, seizures, kidney failure or coma, whereas the most common side effect of penicillin is what?

Answer 19

Hypersensitivity

*10% of people are allergic to Penicillin

Question 20

Typically used for its resistance to many older penicillinases which b-lactam group are typically tolerated by patients with penicillin allergy and are moderate-broad spectrum?

Answer 20

Cephalosporins

Question 21

What two things increase as the generation of cephalosporin increases?

Answer 21

Gram (-) activity and B-lactamase resistance

*reduced Gram (+) activity of 2-4 Gen may result in superinfection

Question 22

Not the first choice for any infection, which Generation of cephalosporins are mainly prophylactic, and do not penetrate the CNS of which Cefazolin is an example?

Answer 22

1st generation cephalosporins

Question 23

Cefaclor, cefuroxime and cefoxitin are examples of which generation of cephalosporins?

Answer 23

2nd generation

*Cefoxitin has enhanced anaerobe activity and extended B-lactamase resistance

Question 24

Cefotaxime/ceftriaxone, ceftazimide and cefdinir are which generation of cephalosporins that are active agains Gram (-) rods, and penetrate CNS sufficient to treat meningitis?

Answer 24

3rd generation cephalosporins

*Cefdinir is highest selling cephalosporin

Question 25

Cefepime and Ceftaroline are what generation of cephalosporin?

Answer 25

4th and 5th generation respectively

Question 26

Imipenem is usually coadministered with cilistatin to resist renal degradation, has broadest antibacterial activity known to man and is part of what b-lactam antibiotic group?

Answer 26

Carbapenems

Question 27

What are three examples of non-b-lactam antibacterials that inhibit cell wall synthesis?

Answer 27

1-Vancomycin (IV)
2-Bacitracin (Topical against Gram -)
3-Daptomycin

Question 28

Which non-b-lactam is used again complicated skin infections, bloodstream, endocarditis, bone and joint infections and meningitis caused by MRSA?

Answer 28

Vancomycin

*not as affective against MRSA as nafcillin, is nephrotoxic and ototoxic especially around aminoglycosides

Question 29

Which non-b-lactam is bactericidal agains gram (+) and is active against MRSA and vancomycin resistant enterococcus?

Answer 29

Daptomycin (IV)