36.beta lactams penicilin

Question 1

what is the classification of penicillins?

Answer 1

1.narrow spectrum
-penicillase unstable
-penicillase stable

2.wide spectrum semi-synthetic

3.protected

Question 2

name
narrow spectrum penicillines
unstable

Answer 2

1. benzylpenicillin - flac.1,000,000 IU
2. phenoxymethypenicillin (ospen) - tab.500mg
3. benzathin benzylpenicillin (Benzacillin) - flac. 1,200,000 IU

Question 3

advantages of
narrow spectrum penicillines
unstable

Answer 3

1. bactericidal,
2. effective mainly agains Gr(+)
   incl. Streptoccoci,
   Meningococi,
   Gonococi,
   Spirochetes.

Question 4

disadvantages of
narrow spectrum penicillines
penicillase unstable

Answer 4

1. narrow spectrum;
2. non effective agains Staph. aureus;
3. can’t use oraly.

Question 5

how are Benzylpenicillin (penicillin G) and Benzathin benzylpenicillin (benzacilin) applied?

Answer 5

parenterally

Question 6

name drugs in the group of
penicillase-stable
narrow spectrum semi-synthetic penicillines

Answer 6

1. cloxacillin - caps.250mg
2. oxacillin - caps.250mg

Question 7

adavantages of the group of
penicillase-stable
narrow spectrum semi-synthetic penicillines

Answer 7

1-β-lactamase-resistant penicillins
2 - Cloxacillin is more active than Oxacillin against Staph.

Question 8

disadvantages of
narrow spectrum semi-synthetic penicillines
penicillase stable

Answer 8

1-narrow spectrum
2-not effective against gram -

Question 9

indications for use of narrow spectrum
penicillase stable drugs?

Answer 9

1.bronchopneumonia
2.acute endocarditis
3.sepsis
4.furunculosis

Question 10

which are the 3 groups of broad spectrum penicillins

Answer 10

1.amino-penicillins
2.carboxi-penicillins (against proteus and h.influenzae)
3.ureido-penicillins

Question 11

which are the advantages of broad spectrum penicillins

Answer 11

1. Broad spectrum against Gr (-) microorganisms.
2. are less active against Gr (+) than narrow-spectrum penicillins.
3. ureido - against pseudomonos and e.coli
4. carboxi - against proteus and h.influenzae

Question 12

Amoxicillin is active against

Answer 12

1.gram +
2. gram -
3. h.pylori

Question 13

name drugs in the group of protected (combined) penicillines

Answer 13

1.augmentin - tab.1000mg
2.unasyn

Question 14

what are the advantages of combined penicillines?

Answer 14

1 - are risk of induction of the synthesis of more beta-lactamases.
2- are applied to treat haevy infections together with aminoglycosides (but not in the same syringe).

Question 15

what are the disadvantages of protected (combined) penicillines?

Answer 15

methicilline-resistant strains are not sensitive against them

Question 16

MoA of penicillins

Answer 16

1- inhibit the synthesis of mucopeptide murein the bacterial cell wall
2- block **transpeptidase enzymes **
which makes the peptidoglycan unstable and causes bacteriolysis and cell death
- Bactericidal!

Question 17

pharmacokinetics of penicillins
a,d,m,e

Answer 17

• A- acid stable given orally, acid unstable given parenterally
• D- PP binding, can cross FPB in meningitis, only extracellular
• M- partially by liver, then kidneys
• E- active metabolites in urine

Question 18

absorption of penicillins

Answer 18

1.broad spectrum are destroyed in stomach
-not applied orally
2.i.m

Question 19

elimination of penicillins

Answer 19

through urine with tubular secretion

Question 20

application of benzylpenicillin

Answer 20

im
iv
ONLY!

Question 21

how to apply phenoximethylpenicillin (ospen)

Answer 21

orally

Question 22

absorption of oxacillin and cloxacillin

Answer 22

1.well absorbed in GIT
2. reduced absorption by food

Question 23

absorption of Amoxicillin

Answer 23

high absorption
-not influenced by food

Question 24

name aminopenicillines

Answer 24

ampicillin - caps.250mg
amoxicillin - caps.250mg

Question 25

name carboxipenicillins

Answer 25

carbenicillin - flac.1g

Question 26

name ureidopenicillins

Answer 26

1.azlocillin - flac 1g
2. mezlociliin - flac 1g
3. piperacillin - flac 1g

Question 27

absorption of ampicillin

Answer 27

low
-decreases with food

Question 28

how are carboxy and ureidopenicillins applied?

Answer 28

parenterally : i.v
-not absorbed

Question 29

ADRs of penicillins- allergic reactions

Answer 29

Type I – anaphylactic shock,
urticaria,
Quincke’s edema
Type II – penicillins do not have organ toxicity!!!, but play the role of haptens and
by immune-mediated mechanism lead to hepatitis, interstitial nephritis, hemolytic anemia, leukopenia and thrombocytopenia.
Type III – serum sickness
Type IV – delayed hypersensitivity.

Question 30

ADRs of penicillins

Answer 30

1. Dysbacteriosis – In broad-spectrum oral or parenteral penicillins, which are also excreted in the bile.
2. Penicillin measles
3. Changes in laboratory parameters - false positive Coombs test and urine sugar
4. Local irritant action
5. Neurotoxicity & seizures – when high doses administered endolumbar.
6. Jarish-Herzheimer’s reaction (endotoxic shock) – treatment of syphilis with penicillins causes rapid destruction of treponemes and the release of large amounts of endotoxins, which cause death.
   6.microemboli

Question 31

drug interactions of penicillins

Answer 31

1. In vitro incompatibility with aminoglycosides
   (do not mix in a syringe or jar and be injected i.m. at different sites).
2. In vivo – synergism with other beta-lactams.
   Ex.: Cloxacillin + Ampicillin = Cloxampicin with
   extended antibacterial spectrum.
3. In vivo – antagonism:
   broad-spectrum oral penicillins reduce the effect of oral contraceptive

Question 32

which combination with penicillins broadens the spectrum of activity

Answer 32

aminoglycosides and cephalosporins (but not in vitro)

Question 33

which combination with penicillins reduces the activity?

Answer 33

tetracyclines

Question 34

penicillins can be combined with …. for a better effect

Answer 34

1.beta lactamases e.g clavulanic acid
2.other bacteriocidal antibiotics

Question 35

contraindications for penicillins

Answer 35

hypersensitivity

Question 36

defintion of penicillins

Answer 36

Penicillins area group of β-lactam antibiotics originally obtained from Penicillium moulds,