Penicillin Flashcards

1
Q

MOA of penicillin?

A

bactericidal– inhibits the with the last step of synthesis of cell wall by three ways
Penicillin binding Proteins
inhibition of transpeptidation reaction(inhibibtion of cross linkage)
Production of autolysin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where are PBP located?

A

bacterial cytoplasmic memberane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

why is staph resistant to methicillin

A

due to alterations in PBP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how does production of autolysin effect the bacterial cell?

A

Many bacteria, particularly the grampositive
cocci, produce degradative enzymes (autolysins) that
participate in the normal remodeling of the bacterial cell wall. In
the presence of a penicillin, the degradative action of the autolysins
proceeds in the absence of cell wall synthesis. Thus, the
antibacterial effect of a penicillin is the result of both inhibition
of cell wall synthesis and destruction of the existing cell wall by
autolysins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how are penicillins excreted out of the body?

A

excreted by kidney (excreted unchanged in urine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the mechanism of excretion of penicillins through kidney?

A

Active tubular Excretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

the excretion of penicllin is effected by which drug?

A

probenecid(causes inhibition of active tubular excretion)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

the excretion of penicllins is effected by which drug?

A

probenecid(causes inhibition of active tubular excretion)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the only penicllin that is excreted by a route other than kidney

A

Nafcillin (excreted by a biliary route)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

absorption of penicillin after oral administration

A

incompletely absorbed (amoxicillin is completely absorbed)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

antibacterial spectrum of penicillins

A

G+ve: → cell wall is easily penetrated.
G-ve: → envelope around cell wall, however porins permit entrance of penicillins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

which microorganism lacks porins that makes it very resistant to penicillin action?

A

pseudomonas aeruginosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Penicillins in “Natural pencillins”?

A

Penicllin G
Penicillin V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which is more acid stable G or V

A

V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

which gram + cocci is natural penicillin active against?

A

Streptococcus(Pneumonia, pyrogenes, viridans)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

which gram - cocci is natural penicillin active against?

A

neisseria (gonorrhea, meningitides)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

is natural penicillin active against spirochetes?

A

treponema palladium(syphilis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

which anerobic is natural penicillin active against?

A

clsostridium pefringens

19
Q

which gram + bacilli is natural penicillin active against?

A

corynebacterium diptheria
bacillus anthracis

20
Q

the class Anti Staphylococcal penicllins include which antibiotics?

A

Methicillin
Oxacillin
Nafcillin
Dicloxacillin
MOND

21
Q

Are antistaphylococcal penicillins (MOND) resistant to penicillanase (Beta lactamase)?

22
Q

what toxicity does methicillin cause?

A

interstitial nephritis

23
Q

What is MRSA and its treatment?

A

Methicillin resistant Staph Aureus

treated with vancomycin

24
Q

antibiotics in Extended spectrum

A

Ampicillin and amoxicillin

25
spectrum of extended spectrum antibiotics?
same as penicillin g but with more effect on gram- bacilli( H influenza, E coli)
26
drug of choice in listeria monocytogenes(Gram +)
Amoxicillin
27
which drug is used as a prophylactic agent to prevent bacterial endocarditis
Amoxicillin
28
what is done to extended spec antibiotics to inc their activity against Beta lactamase producing organisms
sulbactam and clavulanic acid
29
what drug are included in antipseudomonal penicillins?
(Carbenicillin, Piperacillin, Ticarcillin) [CPT]
30
which organism do (Carbenicillin, Piperacillin, Ticarcillin) [CPT] acts on
pseudomonas aeruginosa
31
to enhance the activity of piperacillin what is it combined with
Tazobactam
32
to enhance the activity of ticarcillin what is it combined with
clavulinic ACID
33
Penicillins + Aminoglycosides
Synergistic effect as penicillins inhibit cell wall synthesis & A.G. inhibits protein synthesis with enhanced permeability. *Caution: penicillin + A.G not in the same vial as: → (+ve) A.G. + (-ve) penicillin→ ppt
34
Routes of administration:* *CPT & their combination
IV & IM
35
Route of administration Penicillin V, Amoxicillin & Ampicillin +Clavulonic acid
oral
36
Route of administration Procaine penicillin G& benzathine penicillin G
depot IM slowly absorbed into the circulation
37
route of administraion *MOND→
given before food(30-60 min)
38
adverse effects of penicillins
Hypersensitivity → most common. The metabolite penicilloic acid reacts with proteins→ Hapten that causes immune Rx. 2) Diarrhea→ pseudomembranous colitis. 3) Nephritis→ mainly Methicillin. 4) Neurotoxicity→ epileptic patients at risk. 5) Hematologic toxicities→ ↓ coagulation (CPT). 6) Cation toxicity: penicillins are administered as Na+ or K+ salt.
39
*Test of penicillins Hypersensitivity:
Penicilloyl- polylysine skin test
40
ticarcillin causes what as a disodium salt
inc risk of HTN also has an antiplatelet effect
41
why is ticarcillin preferred over carbenicillin in pts with CHF
Because dose of Ticarcillin is 1/2 that of Carbenicillin.
42
patient with penicillin allergy don't shift to cephalosporin but shift to
erythromycin
43
cross hypersensitivity risk bw penicillin and cephalosporin
10%