Antibiotic Drugs - EXAM 2 Flashcards
What is the MOA for beta-lactam Abx?
- inhibit bacterial cell wall synthesis
What are 3 examples of Beta lactam abx?
- pencilillins
- cephalosporins
- carbapenems
PCN - beta lactam
Why does resistance develop?
- beta-lactamase enzyme over time
PCN - beta lactam
What bacteria is PCN the DOC for?
What types of infections?
- streptococci
- meningococci
- pneumococci
mostly gram + - skin infection, catheter infections, URI
PCN- beta lactam
What are 4 PCN drugs?
- Pencillin G
- methicillin
- Nafcillin
- Amoxicillin
PCN - beta lactam
Adv. Reactions of PCNs?
- hypersensitivity
- GI upset - lg. doses
- vaginal candidiasis - fungal overgrowth
Cephalosporins - Beta Lactam
Is there resistance?
- not as much as w/ PCN
- broader spectrum than PCN
resistance can occur w/ the PCN-binding protein altering its structure
Cephalosporins - Beta Lactam
What are Cephalosporins the DOC for?
surgical prophylaxis
* can be used w/ PCN allergy (if not anaphyl.)
Cephalosporins - Beta Lactam
1st gen drugs:
Cefazolin (Ancef)
does not cross BBB
* gram + (staph, strept.)
* cellulitis, abscesses, UTI, URI
Cephalosporins - Beta Lactam
2nd gen drugs:
gram coverage:
uses:
Cefuroxime (Ceftin, Zinacef)
Cefoxitin (Mefoxin)
Cefotetan (Cefotan)
gram -
Uses: H-inf. pneumonia, UTI, otitis media
Cephalosporins - Beta Lactam
3rd gen drugs:
gram coverage:
Uses:
Cefotaxime (Claforan)
Ceftriaxone (Rocephin)
Ceftazidime (Fortaz)
some cross BBB
- gram -
- Uses: resistance, meningitis
Cephalosporins - Beta Lactam
4th gen drugs:
Uses:
Cefepime (Maxipime)
* most resistant to beta-lactamase
* penetrates BBB well
* uses: multi-resistant organisms
Cephalosporins - Beta Lactam
Adv. Reactions?
- hypersensitivity - not common
- potential production deficit of Vit. K
- do not use in clotting disorders
What Abx do we use in the case of true anaphylaxis to beta-lactams?
- Vancomycin
- Clindamycin
Carbapenem - Beta Lactam
Will resistance happen?
- prob not - can inhibit beta-lactamase enzyme
most broad spectrum of all beta-lactams
Carbapenem - Beta Lactam
What bacteria does it work against?
Uses:
gram -
* P. Aeruginosa
* Enterobacter
uses:
* last line: intra-abdominal, resistant UTI, pneumonia, ruptured bowel
Carbapenems - Beta Lactam
Does it penetrate BBB?
Drugs Examples:
most penetrate BBB
- Ertapenem (Invanz)
- Merropenem (Merrem)
- Imipenem (Primaxin)
Carbapenem - Beta Lactam
Adv. Reactions?
- n/v
- diarrhea
- rash
- injection site rxn
What Abx class do we not want to give to pts on Depakote?
- Carbapenems - Beta Lactam
- causes decreased Depakote levels by up to 90% = seizure
Vancomycin
MOA:
- inhibits cell wall synthesis
- prevents bacteria from dividing & replicating
- only works if bacteria are dividing
Vanco
Gram coverage?
What infections is it good for?
gram +
* blood stream infections
* endocarditis (valvular, cardiopulm. bypass) - caused by MRSA
Vanco
Adv. Reactions?
frequent
* phblebitis @ inj. site
* chills, fever
* nephrotoxic - peak/trough
* “red man” syndrome - flushing, redness, inflammation
Aminoglycosides
MOA:
- inhibits ribosomal proteins
- so mRNA misreads & bacteria can’t replicate
- synergistic w/ beta-lactams & vanc
Aminoglycosides
Drugs:
- Gentamycin
- Neomycin
Aminoglycosides
Adv. Reactions?
- ototoxic - give slow
- nephrotoxic
- curare-like effect
Aminoglycosides
What factors increase the risk of nephrotoxicity w/ aminoglycosides?
- elderly
- renal insufficiency
- dosing > 5 days
- higher doses
- loop diuretics
Aminoglycosides
What causes the curare-like effect?
- interference w/ Ach receptors
- seen w/ depolarizer Succ
Fluoroquinolones
MOA:
- inhibit DNA protein synthesis
Fluoroquinolones
Gram coverage?
indications?
gram -
* GU surgery
* UTI, bacterial diarrhea, bone/joint infection
Fluoroquinolones
Drugs:
- Ciprofloxacin (Cipro)
- Levofloxacin (Levaquin)
Fluoroquinolones
Adv. Reactions?
- n/v/d
- prolonged QT
- cartilage damage/tendon rupture
Fluoroquinolones
What 3 factors are associated w/ cartilage damage/tendon rupture?
- renal insufficiency
- concurrent steroid use
- advanced age
Metronidazole
MOA/Class:
Class: antiprotozoal/anaerobic antibacterial
MOA: forms toxic byproducts that cause unstable DNA molecules, limiting bacteria ability to proliferate
Metronidazole
indications:
- intra-abdominal infections
- vaginitis
- c-diff
Metronidazole
Adv. rxns?
- nausea
- peripheral neuropathy (long use)
- dilsurfiram like effect - hangover w/ alcohol = flushing, dizziness, HA, chest/abd. pain
Cefazolin Dosing
* < 80kg:
* 81-119kg:
* > 120kg:
re-dose time:
- 1g
- 2g
- 3g
4 hrs
Vancomycin dosing
15mg/kg
