Summary Drugs List of MG: Infectious diseases and Oncology 2023

,Lecture 2: Antibiotics with cell
wall and membrane as their
target
 Penicillin G:
 Target
 Bacterial infections
 only active against fast dividing bacteria
 Mechanism
 It inhibits peptidoglycan synthesis (cell wall synthesis) using β-lactam
 fast excretion via kidney, non-toxic,
 Side effects
 Unstable at acidic conditions, sensitive to all known β-lactamases, less active against gram - frequently
allergic reactions

 Penicillin V:
 Target
 Bacterial infections
 only active against fast dividing bacteria
 Mechanism
 Same as Penicillin G, but electronegative O-atom added so less unstable in acidic conditions, can bypass the
stomach
 It inhibits peptidoglycan synthesis (cell wall synthesis) using β-lactam
 fast excretion via kidney, non-toxic,
 Side effects
 It will stick to many things in the body, so you have to give 4 doses a day.

 Ampicillin:
 Penicillin with the addition of an NH2 group and phenyl group
 Bacterial infections
 Good bioavailablity

 Amoxicillin:
 Penicillin with the addition of an NH2 group and phenol group, also against
gram –
 Bacterial infections
 Excellent bioavailability

 Then instead of an amino group, a carboxyl group is placed on that position. These
are called carboxypenicillins called carbenicillin and carfecillin. These can also be
administered orally and have a better activity against G- bacteria. However, if the R
group is polar it has a poor adsorption.

,  What are common examples regarding lactamase inhibitors (this is called suicide inhibitor)?
 Clavulanic acid: given with amoxicillin
 How does clavulanic acid work?
 Clavulanic acid fits in the bucket of the lactamase forming a complex which is IRRIVERSIBLE

 Sultamicilline: (prodrug) it is a structure that contain the antibacterial and
lactamase inhibitor. When it is in the stomach, due to the low acidity it
cleaves off forming those building block

 Tazobactam
 lactamase inhibitors
 In combination with piperacillin, back-up antibiotic, intensive care
medicine
 Bacterial infections, diabetes-related food infections, febrile neutropenia
 Cephalosporin C
 Inhibition of the transpeptidase enzyme, has a less reactive βlactam ring, good leaving group
 Cefalexin
 1st generation, good against gram+, bad against gram
 Airway infections, skin infections, bladder infections
 Cefoxitin
 2nd generation, urethane group functionality is more stable than ester group, better lactamase stability (steric
hindrance by methoxy group), variable activity against gram+, improved activity against gram
 Infections, very βlactamase resistant
 Ceftobiprole
 ack-up cephalosporin, ‘5th’ generation, anti-MRSA, resistant against Staphylococcus βlactamase, inhibits
Staphylococcus PBP2
 Skin and soft tissue infections, IV, Canada, Switzerland and EU
 Vancomycin
 This is a not beta lactam  it is a back up treatment  only in hospital pharmacy
 It interferes with the cell wall at diffent place
 It inhibits the cross linking
 inhibits the synthesis of the cell wall by binding to peptide chains and preventing cross linking.
 Against which type of bacteria is vancomycin used?
 It is used against gram+ bacilli, often as back-up antibiotic in serious infections.
 Bacitracin

 inhibits the export of building blocks
 Against which type of bacteria is Bacitracin used?
 against gram+ bacilli and is nephrotoxic
 why is it noly used on skin and eyes
 because it is nefrotoxic
 There is poor bioavailability, so often use of cream for skin and eyes.
 Cycloserine
 It is a D-alanine-mimic
 inhibits the attachment of D-alanine amino acids to the peptide chain of NAM.
 Phosphomycin
 inhibits the precursor of peptidoglycan
 Against which type of bacteria is Fosfomycin used?