A.bac: Cell Wall Synthesis Inhibitors

Question 1

Basic structure of penicillins.

Explain how Penicilloic acid is yielded.

Answer 1

Thiazolidine ring attached to a B-lactam ring
Hydrolysis of B lac yields Penicilloic acid- no activity
(Pen metabolized by penicillinase to this)

Question 2

penicillins MOA

Answer 2

Cell wall inhibitors— interferes with transpeptidation rxn of bac. cell wall synthesis— halting formation of pep.—cell death

Question 3

All penicillins are: 
-dec. abs’n by food except
-excreted renally except 
What is the oral form of Penicillin?
Wc are amino penicillins?

Answer 3

-Amoxi
-Ampi and Naf- mainly hepatic
Pen. V
Ampi and Amino

Question 4

ADE of penicillins

-Naf -Methi -Ampi -Oxa

Answer 4

-Naf- Neutropenia
Methi - interstitial nephritis
Ampi - P. colitis
Oxa - Hepatits

Question 5

R= Substitution of R effects in solubility’s salts are given orally

Answer 5

R= benzyl penicillin - Pen G
R= phenoxymethyl - Pen V

Question 6

A chemical drug-drug incompatibility btwn wc drug and B lac in which both drugs are inactived.

Answer 6

React with each other that N-acylation of C1 of this drug by B lac bond takes place

Question 7

B lactamase inhibitors, ADR

Answer 7

Amoxi-clav
Sulbactam-Ampicillin
Tazo-Piperazine
*ADR GI disturbances

Question 8

Methicillin dosage forms

• Penicillin G benzathine has long half life of?

Answer 8

Methicillin is only IV and IM

24 to 60 hours

Question 9

DOC for otitis media? A child less than 2 yrs allergic penicillin, what is the drug choice for otitis media?
For Endocarditis prophylaxis.

Answer 9

Amoxi-clav then allergic, Clindmycin >3 years, macrolides

Amoxi. Others, Macrolides or Clindamycin

Question 10

Penicillins are ineffective in tx of bacterial infections assoc with? What drugs for tx?

Answer 10

Mycoplasma.

Macrolide, Tetracyclines

Question 11

P. colitis assoc. diarr is tx by?

Answer 11

Oral vancomycin.

*also MRSA infxs

Question 12

What is used for penicillin allergy test?

Answer 12

Penicilloyl polylysin

Question 13

Which antibiotic is both penicillinase and acid resistant

Answer 13

Cloxacillin

Question 14

Additional ring for Cephalosporin chemical structure.

Answer 14

Dihydrothiazine ring

*none in B lac

Question 15

Gram activity and CNS penetration

Answer 15

Gram +ve: 4th gen ➡️ 1st gen
Gram -ve and CNS penetration:
1st gen ➡️ 4th gen

Question 16

1st gen Cepha.

Answer 16

Cephalexin, Cefazolin, Cefadroxil, Cephalotin, Ceftiadine, Cephapirin
“PH”

Question 17

2nd gen Cepha.

Answer 17

Cefuroxime, Cefoxitin, Cifoletan, Cefachlor, Cefonicid, Cefrozil, Ceforamide
“Cef +vowel, except PRO)

Question 18

3rd gen. Cepha

4th.

Answer 18

Ceftriaxone, Ceftaxime, Cefoperazone, Ceftazidime, Cefixime
(CEF +consonant PERA TAX DIME FIX)

4th: Cefepime

Question 19

Cepha 2nd gen available as i.v?
3rd generation available as oral?
1st gen as IV?

Answer 19

cefuroxime sodium
cefexime
Cefazolin

Question 20

Monobactam what gram and drug?

Answer 20

gram -ve
Aztreonam- IV, renally excreted.
SE skin rash, elevation liver enz (SGPT, SGOT)

Question 21

Struc. related to B lac and known for pseudomonal activity and drug examples:

Answer 21

Carbapenems:

i. Ertepenem- longest t1/2, less active than ii and iii, no pseudo act.
ii. Imipenem (+ Cilastatin)- to prolong DOA, gram + and -ve, anaerobes IMI
iii. Meropenem- sim. to i and ii but w slightly greater activity

Question 22

Vancomycin is produced from which bacteria? MOA

Answer 22

Strep. orientalis
MOA binds firmly to D- Ala-D-Ala.
Terminus of peptidoglycan peptide➡️ weakening of pep.➡️ CELL LYSIS

Question 23

Vanco drug synergism and ADE

Answer 23

Syn w Gentamycin and Streptomycin against Enterococcus

ADE: Red neck/man syndrome- flushing of skin by histamine release

Question 24

Ant

Answer 24

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