Penicillins

Front 1

What is the general action of Pen. ?

Back 1

Inhibit transpeptidase enzyme ---> inhibit cross linking ---> decrease rigidity of cell wall ---> cell lysis (cidal)
(competitive antagonist of transpeptidase due to str. similarity )

Front 2

Absolute configuration for activity of Pen. ?

Back 2

3 S , 5 R , 6 R

Front 3

Drawbacks of Pen G ?

Back 3

Hypersensitivity reactions
Narrow spectrum
Acid sensitive ( not taken orally )
B- lactamase sensitive (Therapeutic failure )
Short duration ( taken every 4 hrs --> 6 times daily )

Front 4

Long acting Pen G derivatives ?

Back 4

Benzathine Pen.G ( once a month )
Procaine Pen.G ( once a week )

Front 5

Pen . V is taken orally ?

Back 5

Acid resistance due to presence of a withdrawing gp (O) that decrease the pen. self degradation .

Front 6

B- lactamase resistant pen.s ?

Back 6

Methicillin
Oxacillin
Cloxacillin
Dicloxacillin
Flucloxacillin

Front 7

Role of halogen in Cloxacillin, Dicloxacillin , Flucloxacillin ?

Back 7

Bulk --> B-lactamase resistance
Withdrawing gps --> acid resistance
Lipophilic --> increase bio availability
Increase binding to plasma ptns (++ Duration )

Front 8

Broad spectrum Pen. ?

Back 8

Ampicillin
Carbenicillin

Front 9

Ampicillin is taken Orally While Carbenicillin is not ?

Back 9

Ampicillin have an amino gp that protonate to amonium ion that is very withdrawing increasing acid resistance

carbenicillin contains carboxylic gp --> by decarboxylation turns to Pen.G which is sensitive to acid

Front 10

Poor absorption of Ampicillin have it's advantages and drawbacks ?

Back 10

Advantage : Used to act locally in GIT infections

Disadvantage : kills the normal bacterial flora leading to GIT disturbance --> Diarrhea
and also decreased Bio availability of the drug

Front 11

A prodrug of Ampicillin and the aim of it ? ( on N side )

Back 11

Hitacillin
to overcome polymerization that leads to Hypersensitivity and losing activity

Front 12

A prodrug of Ampicillin ? ( on COOH side )

Back 12

Pivampicillin
Bacampicillin

Front 13

Ampicillin deriv. and the aim of it ?

Back 13

Amoxicillin
( ++ absorption by ++ polarity to increase dissolution rate )

Front 14

Deriv . of Carbenicillin and the aim ?

Back 14

Ticarcillin
( ++ tissue penetration by increasing lipophilicity )

Front 15

Thiophene bio isostere of carbenicillin ?

Back 15

Ticarcillin

Front 16

Prodrug of Carbenicillin ?

Back 16

Carficillin
( to be taken orally ,, No decarboxylation ,, covering the COOH gp )

Front 17

B-lactamase inhibitors ?

Back 17

Sulbactam
Calvulanic acid

Front 18

Amoxicillin + Calvulenic a'

Back 18

Augmentin®

Front 19

Ampicillin + Sulbactam

Back 19

Unasyn®

Front 20

Oxapenam derivative ?

Back 20

Clavulanic a'

Front 21

M.O.A of B-lactamase inhibitors ?

Back 21

irreversible suicidal inhibitors

Front 22

What is the difference bet. allergy in Pen.G and Ampicillin ?

Back 22

In Pen. G it is a hapten that turns to antigen when binds to Transpeptidase ---> Ab - Ag reaction

While in ampicillin allergy is through Polymerization , the polymer itself is Antigenic

Front 23

Steps of Ampicillin synthesis ?

Back 23

1- Protection of amino gp (- HCl )
( Using Benzyl oxy carbonyl cl )
2- Activation of COOH gp ( - HCl )
( Using Ethyl oxy carbonyl cl )
3- Add 6- APA
4- Remove protection ( by reductive debenzylation using Pd / H2 )

Front 24

The start materials of Ampicillin synthesis ?

Back 24

Phenyl Glycine + 6 - APA

Front 25

Why not use SoCl2 in activation of COOH in Ampicillin synthesis ?

Back 25

Bec. the product will be a racemic mix. ( D & L ) and the active form of Ampicillin is D only .

Front 26

Carbapenems ?

Back 26

Thienamicin
Imipenam
Meropenam

Front 27

Why Cilastatin is co-administered with imipenam ?

Back 27

Dehydropeptidase enzyme metabolize imipenam to a Toxic metabolite ( inactive and affect kidney ) so must use a dehydropeptidase inhibitor ( cilastatin )

Front 28

A totally synthetic B-lactam A.B ?

Back 28

Aztreonam ( Monobactam )

Front 29

Role of Syn iminoether in Aztreonam?

Back 29

Bulk --> B-lactamase resistance

Front 30

Role of Amino thiazole in Aztreonam ?

Back 30

Increase activity on G- Bacteria .

Front 31

Degradation of Pivampicillin gives ........... ?

Back 31

Ampicillin + Pivallic a' +Formaldehyde

Front 32

Degradation of Bacampicillin gives ....... ?

Back 32

Ampicillin + Ethanol + Carbonic a' + Acetaldehyde

Front 33

Enzyme that degrade Piv . and Bac . ?

Back 33

Estrase in blood

Front 34

Mutual prodrug for increasing absorption ?

Back 34

Sultamicillin

Front 35

Ampicillin + Sulbactam is not taken orally ?

Back 35

Both have poor GIT absorption .

Front 36

Sources of 6-APA ?

Back 36

1- Direct from the fermentation media
( poor yield )
2- From Pen.G or Pen.V by acylase enzyme that hydrolyse the side chain amide bond
( high yield )

Front 37

Oral pen.s are ..................... ?

Back 37

Pen. V
Phenethicillin
Ampicillin
Amoxicillin
Hitacillin
Pivampicillin
Bacampicillin
Oxacillin
cloxacillin
Flucloxacillin
Dicloxacillin
Carfecillin

Front 38

Role of methyl gp in Aztreonam ?

Back 38

Bulk ---> ++ B-lactamase resistance

Front 39

Role of COOH gp in Aztreonam ?

Back 39

Act on pseudomonous bacteria

Front 40

Action of SO3H gp in Aztreonam ?

Back 40

Electron withdrawing gp ---> increase reactivity

Front 41

Methicillin is not taken Orally ?

Back 41

Bec. it contains 2 MeO gps which are donating gps ---> ++ Nuclophilicity of ( C=O ) and decrease the drug stability ( Acid sensitive )