Cell Wall Antibiotics

Which classes of drugs are beta lactams

Penicillins

Cephalosporins

Monobactams

Carbapenems

B lactamase Inhibitors

Which drugs are Non B lactams

Glycopeptides

Telavancin

Dalbavancin

Daptomycin

Fosfomycin

Bacitracin

Polymyxin

What are the differences between gram positive and gram negative cell walls

Gram positive has thick peptidoglycan layers and gram negative has an outermembrane that gram positive doesnt have

Explain how beta lactams block bacterial cell walls from getting  built 

Penicillins and Cephalosporins block the release of  D alanine  and also inihibit transpeptidase enzyme 

What do beta lactamase drugs target

penicillin binding protein or transpetidase PBP

What is the MOA of penicillin

Penicillin mimics D alanyl D-alanine and irreveirsibly binds and inhibits PBP enzyme by forming a penicilloyl enzyme intermediate

What are Penicillins active against

• Gram Positive

• Gram negative COCCI 

  • Non B lactamase producing anaerobes

What is anti staphylocci penicillins like methicillin, nafcillin, oxacillin active agianst

Staphylococci

Streptococci

S epidermidis

What is Extended spectrum penicillins active against

Better against gram negative

How does bacteria become resistant to penicilin 

Bacteria produces Beta lactamase that inhibits/breaks down penicillin 

Modifies the PBP so that methicillin doesnt work against staph and penicillin doesnt work against pneumococci and enterococci

In gram negative the antibiotic cant penetrate the bacteria to go to PBP

bacteria creates eflux

Penicillinase acts on which chemical moiety

beta lactam ring

How are Penicillins excreted

Kidneys and mostly eliminated unchanged

What kind of stable are Penicillins 

Acid stable and well absorbed 

What is the penetration of penicillins like

Penetration into the eye, prostate and CNS is poor

What is Penicillin G used for

Infections by

Streptococci

meningococci

eneterococi

What is Benzathine Penicillin and Procaine for 

Im injection for B-hemolytic strep pharyngitis 

What is indicated for penicillinase producing staphylococci/

Nafcillin, cloxacillin and dicloxacillin

What is nafcillin for

Iv infusion for serious sustemic staph infections

What is dicloxacillin for 

Narrow spectrum for gram positive

Staph 

Strep p 

Srep pneumoniae 

What are aminopenicillins

Extended spectrum

amoxicillin

ampicillin

What is amoxicillin used for

UTI

sinusitis

otitis

Lower respiratory tract infections

pneumococci

What is Ampicillin used for

Pneumococci 

reporatory tract infections 

bacterial meningitis 

septicemia

endocarditis

uti 

gi infections

What is ampicillin not good for

Common nosocmial infection s

Klebsiella, enterobacter

p aeruginosa

What is carboxypenicillins used for such as ticarcillin

Pseudomans, enterobacter and proteus

septicemia

Lower respiratory infections

Bone and joint

skin

uti

gynecologic

intra abdominal

What are ureidopenicillins 

Piperacillin 

What is piperacillin used for

Pseudomonas, klebsiella and other gram negatives

What are adverse effects of Penicillins

Hypersensitivity

anaphylaxis

seizures

What are drug drug interactions of penicillins

Pen G and Pen V decrease effectiveness of oral contraceptives 

colestipol decreases PEN V absorption 

Probenecid increases plasma levels 

Amoxicillin increased risk of rash with allopurinol 

Are penicillins bacteriastatic or bacteriacidal

Bacteriacidal

What is different about cephalosporin structure

Six member ring with a side chain

What are cephalosporins resistant to

Beta lactamases

How many generations of cephalosporins are there

5

What happens as you get to a later generation like 5th gen compared to 1st gen

It becomes more gram negative resistant and beta lactamse resistant

What charge are all cephalosporins resistant against

Gram positive

What does R1 of cephalosporins influence

the activity 

What does R2 of cephalosporins effect

the pharmokinetics

How does bacteria become resistant against cephalosporins

Decreased concentration at sites of action

altered PBP 1A and 2X that decrease affinity for cephalosproins bad for 3rd gen

Bacteria creates cephaolosporinase that hydrolyzes beta lactamases

What are examples of first gen antibiotics

Cefazolin

Cephalexin

What do first gen cephalosporins have a high activity against 

Gram positive cocci 

Strep

Staphylococci 

What are the clinal uses of Cephlaexin

UTI

StaphCOCCI infections

StreptoCOCCI infections

What is cefazolin clinically used for

Surgical prophylaxis

Penicillinase producing e coli or pneumoniae

Staph and Strep Coccal infections

What are second generation cephalosporins

Cefuroxime 

Cefotetan

What do second gen cephalosporins have a high activity against

Klebsiella and gram positive cocci

What are oral 2nd gen cephalosporins for

B lactamse producing H influenaze

Sinusitis

Otiitis

lower respiratory tract infections

What is cefuroxime clinically used for 

Community acquired pneumonia 

What are the 3rd gen cephalosporins

Cefotaxime

Ceftazidime

Ceftrixone

Cefixime

What do 3rd gen cephalosporins have high activity against

Citrobacter

Haemophilus

B fragilis

What are the oral 3rd gen cephalosporings

Cefixime and Cefpodime 

how is ceftriaxone elininated

Biliary tract so liver

What are cetriaxone and cefotaxime clinically used for

Menigitis

What are 3rd gen cephalosporins not used for 

Enterobacter infection 

When is cetazidime and avibactam used

for neutropenic febrile immunocompromised patients

What is a 4th generation cephalosporin

Cefepime

What is cefepime resistant to 

More resistant to chromosolal b lactamases 

What does cefepime have good activity against

P aeruginosa

enterobacteriaceae

S aureus

S pneumoniae

What is the clinical use of Cefepime

Enterobacter infections and empiric therapy of febrile neutropenia

What is Ceftaroline fosamil active against

MRSA and CAP

What are teh cephalosporins + beta lactamase inhibitor combinations

Ceftazidime + avibactam

Ceftolozane + tazobactam

for hospital acquired pneumonia, complicated UTI and abdominal infections

What are the adverse effects of cephalosporins

Hypersensitivity

Renal Toxicity

Leukopenia and thrompocytopenia

C diff dirrahea

What is the structure of monobactams 

Monocyclic Beta lactam ring

What is the MOA of monobactams

binds to PBP 3 and PBP 1A

What is an example of monobactam

Aztreonam

What is aztroneum active against

aerobic gram negative rods 

Where is aztrenoam distributed

CSF

What are the clinical uses of aztreonam

pneumonia, meningitis, sepsis,

What are some examples of carbapenams 

Doripenam 

Etrapenem 

Imipenem 

Meropenem

What is the MoA of carbapenems

Binds to PBP and disrupts bacterial cell wall synthesis and causes death of susceptible microorganisms

What is the spectrum of Imipenem and cilastatin

Broad gram negative rods, gram positive organisms and anerobes

What is Imipenam + cilastatin reistant to 

Beta lactamases 

What is imipenem inactivated by

dehydropeptidases in renal tubules

What is the clinical use of Carbapenems

UTI

Lower respiratory infections

Intra abdominal and gynecological infections

Treatment of enterobacter infections

Which carbepenam is not inactivated by dehydropeptidases

Doripenam and Meropenam 

What is doripenam and meropenam better for

Gram negatives and less active for gram positives

Are beta lactamase inhibitors antibiotics

No but they increase the spectrum and dont kill bacteriaW

Which b lactamase inhibitor is a non beta lactam beta lactamase inhibitor

Avibactam

What are examples of b lactamase inhibitors

Amox/potass clauvulanate

Ampicillin/sulbactam sodium

piperacillin and tazobactum

Ticarllin/clauv potas

ceftazidime/avibactam

ceftolazene + tazobactam

What is the MoA of b-lactamase inhibitors

Potent irreversible inhibitors that resemble beta lactam and are weak antibacterials protect penicillins and cephalosporins

What are examples of Glycopeptides 

Vancomycin 

Telavancin 

Dalbavancin

What is the MOA of vancomycin

Prevents polymerization binding of D alanyl D alanine so disrupts cell wall formation

How does bacteria become resistant to vancomycin

It changes D ala D ala to D lactate

Thickened cell wall with increased D ala D ala resudues doesnt let vancomycin bind

Is vancomycin bacteriostatic or bacteriacidal 

Bactericidal for gram positive bacteria 

What are the clinical uses of glycopeptides

Osteomyelitis and endocarditis

skin, bone joint infections

repiratory tract infections

pneumonia

MRSA

CNS infections like Community acquired bacterial meningitis

What is the oral use for Vancomycin

C difficile

What are the adverse effects of glycopeptides

Ototoxicity and nephrotoxiicty

Vanco infusion reaction 

What drugs are lipoglycopeptides

Telavancin

Dalbavancin

Oritavancin

What is the MoA of telavancin

Disrupts bacterial cell membrane potential and increases membrane permeability

Dalbavancin and Oritavancin moA

Inhibits RNA synthesis and disrupts membrane 

What is the structure of Daptomycin

Cyclic Lipopeptide

What type of activity does Daptomycin have

Concentration Dependent

What is the MoA of daptomycin 

genetic changes in the mprF gene regulating cell membrane charge 

What is the activity of daptomyciin

bactericidal antibiotic selectivity against gram positive bacteria and vancomycin resistant strains of enterococci and s aureus

What are the adverse effects of daptimycin

damage to the musculoskeletal system and rhabdomyolysis

What is the Moa of fosfomycin

Analog of phosphoenolpyruvate and blocks enolpyruvate transferase 

What causes resistance to fosfomycin

Inadequate transport of drug into the cell

What is the activity of fosfomycin

bactericidal against gram positive and gram negative

What is the clinical use of fosfomycin

Uncomplicated lower UTI 

What is the structure of Bacitracin

cyclic peptide mixture

What is the Bacitracin MoA

interferes with dephosphorylation in cycling of the lipid carrier that transfers pertidoglycan subunits to growing cell wall

What are the adverse effects of Bacitracin

highly nephrotoxic

What are the clinical uses of bacitracin

surface lesions of the skin, in wounds or on mucous membranes