Beta-Lactams

Question 1

Beta-Lactam MOA

Answer 1

1. Cross peptidoglycan layer and enter periplasmic space
2. Bind with penicillin binding protien (PBP); aka Transpeptidase
3. Inhibits cross linking and cell wall formation
4. BACTERIACIDAL!!

Question 2

Beta-Lactamase

Answer 2

Inactivation (breaking) of B-lactam ring

Question 3

Characteristics of Penicillin

Answer 3

1. Cell wall synthesis inhibitor
2. Highly protein boud (polar)
3. Stays in blood longer and widely distributed
4. Unbound drug excreted in urine

Question 4

Natural Penicillin (V and G)

Answer 4

Cell wall synthesis inhibitor
Active against streptococcus
ADRS: GI,Hypersensitivity, Secondary infx
DIs: bacteriorstatic abx and ORAL Contraceptives
Synergistic activity with aminoglycoside
Penicillin V = Oral –> minor infx: strep throat, impetigo, otitis media
Penicillin G = Shot/IV –> strep, syphilis, meningococci
EMPTY STOMACH!

Question 5

Antistaph Penicillin

Answer 5

Resistant to staph beta-lactamases
Active against Gram (+) only
i.e. Nafcillin

Question 6

Extended Spectrum Penicillin
Aminopenicillins
Antipseudomonal Penicillin

Answer 6

Covers gram (+) and some gram (-)
–»Can enter Porin channels
Good for Strep!
i.e. Amoxicillin

Question 7

ADR with Amoxicillin

Answer 7

Morbiliform Rash (looks like mumps, itchy)
IgM Response

Question 8

Amoxicillin

Answer 8

Aminopenicillin

Active against Streptococcus (better than pen V)

Question 9

Penicillin with Beta-lactamase inhibitor

Answer 9

Pairing a beta-lactam w/ a B-Lactamase Inhibitor negates resistance; EFFECTIVE = maintains drug activity
Active against Strep
ADRs: GI (common), Hypersensitivity (severe), 2nd infx (likely)
i.e. Amoxicillin with Clavulanate = Augmentin
Used for more invasive bacteria

Question 10

Cephalosporin

Answer 10

Cell Wall Snythesis Inhibitor
Active against gram (+) cocci
Good for ingrown toenails/cellulitis
i.e. Keflex or Cephalexin

Question 11

Carbapenems

Answer 11

MOA similar to beta-lactams but more potent due to high affinity to PBPs
Wide spectrum
Used mostly in hospital and ICU; given IV
***Very renal toxic

Question 12

Monobactams

Answer 12

Have similar structure but lack one of the two rings so little cross-allergy with other beta-lactams
Hospital/ICU; IV/IM

Question 13

Beta Lactam Summary

Answer 13

End in: -cillin, -penem
Start with: ceph-
Lack activity against mycoplasma, chlamydia, MRSA
Seizures can result from very high doses