Antibiotic choice Flashcards
Uses of penicillin
GAS
Syphillis
Confirmed penicillin sensitive pneumococcal infection
Meningococcal Infection (proved sensitive)
Uses of amoxicillin
acute sinusitis, OM
pneumococcus, Hflu, Moraxella -> good for minor infections
Use of ampicillin
Listeria meningitis
Use of augmentin
Persistent minor infections
Use unasyn
mixed infections -> doesn’t cover MRSA
Use of Ticarcillin/Piperacillin
Pseudomonas (burns, neutropenic, hospital aquired pneumonia, CF, ventilator associated pneumonia)
Why do you use higher doses of abx in persistent penumococcal infections
pneumococcus uses penecillin binding protein instead of beta-lactamases
Use of Nafcillin and Oxacillin
Staph Aureus (meth sensitive) cellulitis and endocarditis
Use of PO Dicloxacillin
oral for Staph Aureus
What bugs are not covered by cephalosporins?
Enterococcus
Anaerobes
Use of 1st gen cephalosporin (cefazolin)
minor staph (outpatient cellulitis) Pre-operative cellulitis prophalaxis
Use of 2nd gen cephalosporin (Cefuroxime)
persistent minor infections (like augmentin)
Use of 3rd generation cephalosporin (ceftriaxone, cefotaxime, cefdinir)
more gram negative coverage, good for meningitis
Unique coverage of ceftazidime and cefepime
pseudomonas
Use of IM ceftriaxone
gonorrhea
When do cephalosporins promote resistance?
ESBL producing gram negative organisms: Klebsiells, Actinobacter, Enterobacter, Proteus, Pseudomonas, Serratia, E coli
MOA of aminoglycosides
block protein synthesis at 30s ribosomal unit
Use of aminoglycosides
gram negative infections
Drug combo used in endocarditis
beta-lactams and aminoglycosides
Two conditions when you can’t use aminoglycosides
penumonia and meningitis (poor penetration of meninges)
Best drug in CA pneumonia
Erythromycin
Pro of using azothromycin over erythromycin
fewer side effects, higher patient compliance
MOA of macrolides
bind to 23s RNA of 50s ribosomal subunit
AEs of macrolides
prolonged QT
Use for Trimethoprim-Sulfamethoxazole
minor infections, both gram + and neg
PCP pneumonia
Non-serious soft tissue MRSA infections
Best drug for uncomplicated UTIs
TMP-SFX
Bugs that TMP-SFX doesn’t cover
strep, psudomonas, anaerobes
MOA of TMP-SFX
block nucelotide synthesis by inhibiting bacterial folate synthesis
Use of Nitrofurantoin
UTI of E. coli with sulfa resistance
Pregnancy in UTI
Bad side effect of Nitrofurantoin
can cause interstitial pulmonary fibrosis
MOA of tetracyclines
Inhibit 30s ribosomal subunit
Use for doxycycline
Chlamydia
atypical pneumonia
Rickettsial disease (RMSF)
MOA of quinolones
Inhibit DNA gyrase and topoisomerases
Use of Ciprofloxacin
prostatitis, complicated UTI, diabetic foot ulcer
not penumococcal
Use of Levofloxacin
CA pneumonia, hospitalized pts with gram negative infection
AE of quinolones
Achilles tendon rupture
blocks neuromuscular activity in Myasthenia Gravis
MOA of clindamycin
lincosamide that blocks 50s ribosomal unit
MOA of Metronidazole
promotes free radicals that damage bacterial DNA
Use of clindomycin and metronidazole
anaerobic infections (intrabdominal or pelvic)
Unique uses of metronidazole
C diff
Trichomonas
Giardia
Diet consideration with metronidazole
don’t use alcohol
Use of clindomycin
MRSA
toxin related complications
MOA of vancomycin
inhibits cell wall syntehsis and inhibits peptidoglycan synthesis
Use of vancomycin
MRSA
Staph epidermidis (indwelling catheter)
Ampicillin resistant enterococcal infections
Use of Aztreonam
serious gram negative infections
Can be used in penicillin allergic patients
Use of carbapenams
only drugs effective against ESBL gram negatives
Use of linezolid
gram positives (MRSA, VRE, Peniciilin resistant strep pneumo)
Use of daptomycin
MRSA skin lesions
NOT MRSA pneumonia
Drugs used for psuedomonas
Ticarcillin/Piperacillin Ceftazidime and Cefepime Cipro/Levofloxacin Vancomycin Carbapenams (if ESBL)
Drugs for MRSA
TMP-SFX
Clindomycin
Linezolid
Vancomycin