10 May Antibiotics Flashcards
Primary use for Penicillin G or VK
Syphilis
What drugs are used for methicillin sensitive staph. aureus?
Nafcillin
Dicloxacillin
Oxacillin
On the gram (+) side, what is the to of the ladder if vancomycin is not available or not effective?
Linezolid
Expensive, oral and IV
What are the first drugs meant to expand penicillin coverage to gram (-)?
Amoxicillin
Ampicillin
These should be used for g(-) coverage though we know that amoxicillin covers strep throat
What are the beta-lactamase inhibitors and their most common combinations?
Tazobactam + Piperacillin = Zosyn
Sulbactam + Ampicillin = Unasyn
Clavulanate + Amoxicillin = Augmentin
These beta-lactamase inhibitors are used to expand the coverage of gram(-) drugs to gram(+) as well
Zosyn is broad spectrum and covers most everything except MRSA and fungus
Why was piperacillin developed?
To treat Pseudomonas which is gram (-) and resistant to amoxicillin and ampicillin
When using zosyn, what are you saying you are covering?
Pseudomonas
What is the top of the ladder on the gram(-) side?
Carbapenems
What are the carbapenems?
Imipenem/cilastatin (causes seizures, must have cilastatin)
Meropenem
Ertapenem
What are the most common first and second generation cephalosporins and what are they used for?
First: cefazolin (IM/IV), cephalexin (oral)
Second: Cefoxitin (IM/IV), Cefaclor (oral), Cefuroxime (IM/IV)
These have g(+) coverage and are used for skin infections
What are most common 3rd gen cephalosporins? When used?
Cefotaxime (IM/IV)
Ceftriaxone (IM/IV) (Rocephin)
Omnicef (Oral)
g(-) and g(+) coverage
What is 4th gen cephalosporin and when used?
Cefepime (IV) Pseudomonas Only g(-) coverage
Describe coverage of the fluoroquinolones through the generations
Each generation retains the properties of the one before. Think of baseball diamond.
First and second more g(-), 3rd more g(+)
What are the most common drugs in three generations of fluoroquinolones?
First: Norfloxacin
Second: Cipro, Levo
Third: Moxi
What is the coverage of ciprofloxacin? Primary use?
As a second generation fluoroquinolone, it has great gram(-) coverage and no g(+) coverage
Often used for UTI’s
What is the coverage of levofloxacin? Use?
As a second generation fluoroquinolone, it has great gram(-) coverage and no g(+) coverage
Often used for soft tissue infections
What is the coverage of moxifloxacin? Use?
As a third generation fluoroquinolone, it has great gram(-) coverage and also g(+) coverage
Often used for pneumonia
What are the two drugs for anaerobes?
Clindamycin for anywhere but the abdomen and genital
Metronidazole for abdomen and genital/groin
What is the treatment for CAP?
1) Moxifloxacin (IV or Oral) (avoid if possible to prevent resistance)
2) Ceftriaxone + azithromycin (beta-lactam + macrolide) (used if inpatient)
3) Azithromycin alone (used if sent home)
What is the treatment for HCAP?
Covering MRSA and pseudomonas
Vanc + Zosyn
What is the treatment for meningitis?
Ceftriaxone + Vancomycin +/- steroids +/- ampicillin
For Step 2, everyone gets steroids, only immune compromised get ampicillin
What is the treatment for UTI?
Amoxicillin: pregnant Nitrofurantoin: woman Bactrim: if no renal failure Ceftriaxone: IV only, inpatient management of pyelonephritis Ciprofloxacin: ambulatory pyelonephritis
What is the treatment for cellulitis?
Covering for MRSA or Strep
Vancomycin
Clindamycin
Bactrim
Cefazolin
1st gen cephalosporin
g(+) coverage
IV/IM
Often used for surgery prophylaxis and skin infections because covers g(+) well
Cephalexin
1st gen cephalosporin (Keflex) g(+) coverage Oral One of most common used in USA Used for g(+) infections of bone, middle ear, lungs and skin Also used for endocarditis prophylaxis
What bug can alkalinize the urine and cause struvite crystals in urine and large kidney stones? G(+) or (-)?
Proteus mirabilis
Gram (-)
What are the gram (-) bugs killed by first gen cephalosporins?
PEcK
Proteus
E. coli
Klebsiella
What are the 3 notable 2nd gen cephalosporins?
Cefoxitin
Cefaclor
Cefuroxime
What are the g(-) coverage of 2nd gen cephalosporins?
PEcK HENS Proteus E. coli Klebsiella H. flu Enterobacter Neisseria Serratia
Cefoxitin
2nd gen cephalosporin
Cefaclor
2nd gen cephalosporin
Cefuroxime
2nd gen cephalosporin
Unique in that can cross the BBB
What are the most common 3rd generation cephalosporins?
Cefotaxime
Ceftriaxone
Cefdinir
Ceftazidime
What are 3rd gen cephalosporins generally used for?
Serious g(-) infections that are resistant to other beta-lactams
Cefotaxime
3rd gen cephalosporin
Can cross BBB
Covers most g(-) except pseudomonas, and most g(+) except enterococcus
Ceftriaxone
3rd gen cephalosporin
Rocephin
Single IM injection for gonorrhea
Crosses BBB
Cefdinir
3rd gen cephalosporin
Treats pneumonias, bronchitis, ear infections, sinusitis, pharyngitis, tonsillitis, skin infections
Can make red stool in kids
Ceftazidime
3rd gen cephalosporin Great g(-) and g(+) coverage Treats pseudomonas
What is the 4th gen cephalosporin and its primary use?
Cefepime
Pseudomonas
What are common uses for bactrim?
UTI MRSA Skin infections Traveler's diarrhea Respiratory infections Cholera
How does bactrim work?
Inhibits folate synthesis at two locations by synergistic effect of both drugs
What is the empiric treatment for spontaneous bacterial peritonitis?
Usually a 3rd generation cephalosporin
What is used for SBP prophylaxis?
Fluoroquinolones
