Beta lactams

what are the four groups of beta lactam antibiotics?

Penicillins

Cephalosporins

Carbapenems

Monobactams

within the Penicillins, which are natural Penicillins?

Penicillin G

Penicillin V

the natural Penicillins (G and V), are effective against what type of bacteria?

G+

(especially Streptococcus and Enterococcus, but NOT Staphylococcus)

what is the mechanism of action of Beta lactam antibiotics?

inhibit cell wall synthesis

they do this by inhibiting the enzymes that synthesize the cell wall. they also inhibit peptidoglycan synthesis, making the cell wall deficient of this, leading to an increased internal osmotic pressure until the cell bursts.

are Beta lactams bacteriostatic or bactericidal?

bactericidal

what Penicillins are considered broad spectrum Penicillins?

Ampicillin

Amoxicillin

Piperacillin

Ticarcillin

Ampicillin and Amoxicillin are effective against what type of bacteria?

G+ and G-

(they are most commonly used against E.coli, but are ineffective against Pseudomonas)

are Ampicillin or Amoxicillin a good choice of antibiotic to treat a Pseudomonas infection?

no, they are ineffective against Pseudomonas.

Cloxacillin is a type of ___________, and is effective against ________ bacteria

Penicillin; G+

which Penicillins have the broadest spectrum of activity?

Piperacillin

Ticarcillin

which Penicillins could be selected to treat a Pseudomonas infection?

Piperacillin and Ticarcillin

all other penicillins are ineffective against Pseudomonas

Cephalosporins are classified into 4 generations. Which generation has the broader spectrum?

4th (Cefquinome)

What are the different Cephalosporins that are commonly used in veterinary medicine?

1st generation: Cephalexin, Cefadroxil, Cephapirin, Cefazolin

2nd generation: Cefotixin

3rd generation: Ceftazidime

4th generation: Cefquinome

to which group of beta lactams does Cephalexin belong?

Cephalosporins (1st gen)

to which group of beta lactams does Cephapirin belong?

Cephalosporins (1st gen)

Cefadroxil is part of the _______ group of beta lactams

Cephalosporins (1st gen)

Cefazolin is part of the _______ group of beta lactams

Cephalosporins (1st gen)

Cefotixin is part of the _______ group of beta lactams

Cephalosporins (2nd gen)

what group of beta lactams does Ceftazidime belong to ?

Cephalosporins (3rd gen)

which is the 4th generation Cephalosporin?

Cefquinome

which Cephalosporin has the greatest spectrum of activity?

Cefquinome (it is 4th generation)

what 2 important antibiotics belong to the group Carbapenems?

Merpenem

Doripenem

to what group does Merpenem belong?

Carbapenems

what type of beta lactam is Doripenem?

Carbapenem

what beta lactam antibiotic is a Monobactam?

Aztreonam

which Penicillin is resistant against Beta lactamases?

Cloxacillin

which Penicillins could be administered orally?

Penicillin V, Ampicillin, Amoxicillin

they are acid stable, and oral absorption is reduced with food.

Penicillin G is broken down by gastric acid, so is not absorbed.

can Penicillins access the CNS?

yes, if the BBB is inflamed, it is more permeable. so in high doses, penicillins can cause neurological issues

how do we administer Cephalosporins?

mostly parenterally, because they are unstable in gastric acid (exceptions: Cephalexin, cefadroxil).

in dogs and cats: oral, IM, SC

true or false: Penicillin G is well absorbed orally, so oral administration is a good option.

false- Penicillin G is broken down by gastric acid, so is not well absorbed orally

can Penicillins penetrate into milk?

yes. they can also penetrate urine, saliva, and bile, as well as most bodily tissues.

do Cephalosporins access the CNS?

no

how are beta lactams excreted from the body?

urine

which beta lactam antibiotics inhibit beta-lactamase?

Amoxicillin-clavulanate

Ampicillin-sublactam

Amoxicillin-clavulanate and Ampicillin-sublactam inhibit beta-lactamases. How are these formulations administered?

Amoxicillin-clavulanate: orally in monogastrics. SC or IM in all animals

Ampicillin-sublactam: SC or IM

how do bacteria resist Beta lactam antibiotics?

they produce beta-lactamases- enzymes that hydrolyze and inactivate the beta-lactam ring

are Penicillins considered safe?

yes

however, some animals are allergic.

sometimes can cause GI problems, neurological signs, bleeding, and superinfections (but this is rare)

in veterinary medicine, with what animals do we commonly use Beta-lactam antibiotics?

production animals

Penicillins are commonly administered to production animals to treat...

septicemia, respiratory infections, UTIs