Antibiotics That Act On Cell Wall Flashcards
What are the antibiotics that act on cell wall?
- B-lactams (penicillins, cephalosporins, carbapenems, monobactams)
- vancomycin
- -vancins
Describe structure of penicillins
B- lactam ring attached to a 5-membered ring with sulfur
Describe the structure of cephalosporins.
B-lactam ring attached to a 6 membered ring with sulfur
Describe the structure of carbapenems.
B-lactam ring attached to 5-membered ring without sulfur
Describe the structure of monobactams.
B-lactam ring
How do antibiotics inhibit cell wall synthesis?
They inhibit transpeptidase enzyme responsible for forming transpeptide bond
Name of monobactam drug?
Aztreonam
Penicillins are considered the ………… antibiotics with the least ……….
- safest
- adverse effects
Penicillins are the DOC during ……
Pregnancy
We must perform a ………… test before administering penicillins
Sensitivity
What spectrum do natural penicillins cover?
G +ve
List the natural penicillins.
Penicillin V K
Penicillin G
Penicillin G Benzathine
Penicillin G Procaine
Penicillin V is the DOC for?
Sore throat
Penicillin G Benzathine is the DOC for? Its given …?
Syphillus
IM
How do penicillin g benzathine and penicillin g procaine differ from the other natural penicillins?
Longer duration of action
What are the 2 aminopenicillins?
Amoxicillin
Ampicillin
What spectrum do aminopenicillins cover?
Broad spectrum, but doesnt cover MDR causing nosocomial infections
Amoxicillins are combined with?
Clavulanic acid, a b-lactamase inhibitor
How are amoxicillins administered?
What are they DOC for?
Orally
DOC for otitis media and h.pylori
What are ampicillins combined with?
How are they administered?
Sulbactam, b-lactamase inhibitor
IV
What spectrum do extended spectrum penicillins cover?
Broad spectrum, cover MDR causing nosocomial infections
What is the name of extended spectrum penicillin?
Piperacillin
Piperacillin is combined with?
Tazobactam, a b-lactamase inhibitor
Piperacillin is the DOC in?
Pseudomonas
What are the multidrug resistant bacteria?
- pseudomonas aeruginosa
- e. Coli
- klebsiella
- acinetobacter baumanii
Describe the process of staph aureus resistance.
Staph aureus ➡️ penicillin ➡️ penicillin resistant staph aureus ➡️ methicillin ➡️ MRSA ➡️ vancomycin ➡️ VRSA ➡️ Linezolid
What are anti-staphylococcal penicillins used for?
For penicillin resistant staph aureus
What are the anti-staphylococcal penicillins?
Methicillin
Oxacillin
Nafcillin
Dicloxacillin
Nafcillin is known to be a ……… and must only be taken …….
Vesicant (tissue irritant)
Must only be taken IV in the central line ONLY
What should we do in case of nafcillin extravasation?
- cold packs
- hyaluronidase injection
Penicillin adverse effects?
Seizures
Rash
Diarrhea
Penicillins are contraindicated in?
Patients with sulfa allergy
Penicillin drug interactions?
- all b-lactams (except nafcillin) ⬆️ anticoagulant effect of warfarin
- probencid: ⬇️ elim of penicillins from blood 🩸
List all the types of penicillins:
- natural penicillins
- aminopenicillins
- extended spectrum penicillins
- anti-staphylococcal penicillins
MOA of cephalosporins
Inhibit cell wall synthesis
Cephalosporins dont cover?
Atypical and enterococcus
First generation cephalosporins spectrum and names?
G+ve
Cefazolin
Cefalexin
Second generation cephalosporins spectrum and names?
Spectrum: ⬇️ g+ve than first ⬆️ g-ve than second
(Cefotetan and Cefoxitin are g-ve anaerobic)
Cefuroxime
Cefotetan
Cefoxitin
Third generation cephalosporins spectrum and names?
Group 1:
- cefotaxime
- ceftriaxone
Broad spectrum
Group 2:
- ceftazidime
G-ve including pseudomonas
Fourth generation spectrum and names?
Cefepime
Broad spectrum, including pseudomonas
Fifth generation spectrum and names?
Ceftaroline
Broad spectrum including MRSA (not pseudomonas)
Adverse effects of cephalosporins
Seizures
Rash
GIT upset
Ceftriaxone is contraindicated in? Why?
Neonates (0-28 days)
Because it results in biliary sludgine, and kernictrun
Cefotetan has a side chain called? Why is this significant?
N-methylthiotetrazole
- ⬆️ risk of bleeding
- disulfuram rxn (dont take with alcohol)
Ceftazidim is used in combination with?
Avibactam
Why is ceftazidime/avibactam combination used?
For carbapenem resistant bacteria
Drug interactions of cephalosporins?
Cefuroxime and cefpodoxime need acidic media for absorption
Cant be taken with peptic ulcer drugs
MOA of carbapenems?
Inhibit cell wall synthesis
Route of administration of carbapenems?
IV 💉🩹
What spectrum do carbapenems cover?
Broad spectrum, reserved for MDR g-ve nosocomial infections
Carbapenems do not cover?
Atypical
MRSA
VRSA
What is imipenem/cilastatin combination used for?
To inhibit dipeptidase enzyme produced by kidney
Etrapenem doesnt cover?
Pseudomonas
List carbapenems:
- imipenem
- meropenem
- etrapenem
Adverse effects of carbapenems?
Seizures
Adverse effects of carbapenems are less severe with?
Meropenem
Etrapenem
Carbapenems are contraindicated in?
In penicillin allergy
Drug interactions of carbapenems?
Decrease serum concentration of valproic acid
MOA of monobactams?
Inhibit cell wall synthesis
Name of monobactam drug?
Aztreonam
Spectrum of aztreonam?
G-ve including pseudomonas
Can aztreonam be used in penicillin allergy?
Yes
Vancomycin MOA?
Inhibit cell wall synthesis by binding to D-alanyl D-alanine
Where is vancomycin used?
In hospitals
IV vancomycin is used for?
MRSA
Oral vancomycin is used for?
Clostridium defficile
Due to its hydrophilicity, it remains in the gut
Vancomycin adverse effects?
Ototoxicity
Nephrotoxicity
Red man syndrome (infusion rxn due to high infusion rate ~ do not infuse faster than 1 g/hr)
Drug interactions of vancomycin?
With nephrotoxic drugs and ototoxic drugs
Nephrotoxic drugs that vancomycin interacts with?
Aminoglycosides
Amphotericin B
Loop diuretics
Cisplatin
NSAID’s
Polymixin
Ototoxic drugs that vancomycin interacts with?
Loop diuretics
Cisplatin
Aminoglycosides
MOA of lipoglycopeptides -vancins?
Inhibit cell wall synthesis by binding to D-alanyl D-alanine
Lipoglycopeptides drug names?
Telavancin
Oritavancin
Dalbavancin
Telavancin route of administration?
IV 💉🩹
Telavancin is contraindicated in?
- not used during pregnancy
- not used in QT prolongation (arrhythmic patients, or drugs that cause arrhythmia)
Telavancin adverse effects?
Nephrotoxic
Red man syndrome
Metallic taste
Doesn’t ⬆️ bleeding risk but interferes with coagulation tests (INR, PT)
Oritavancin adverse effects?
- Doesn’t increase bleeding but interferes with coagulation tests (INR, PT)
- red man syndrome
Dalbavancin adverse effects?
- Doesn’t increase bleeding, but interferes with coagulation tests (INR, PT)
- red man syndrome