2. Antibiotics Flashcards
what should you always consider before starting an antibiotic?
- What is the most likely infecting organism?
- Have a gram stain and C&S been done? What are the results?
- Allergies?
- Kidney function (check BUN and Cr)? Many antibiotics are renally metabolized so it is imperative to make sure the kidneys are functioning properly.
- What medications is the patient currently taking? Be concerned of possible drug interactions.
- Any other reason you may or may not want to give the antibiotic?
name that drug: Augmentin
amoxacillin/clavulonic acid
name that drug: Zosyn
piperacillin/tazobactam
name that drug: Unasyn
ampicillin/sulbactam
name that drug: Timentin
ticarcillin/clavulonic acid
name that drug: Zyvox
linezolid
name that drug: Invanz
ertapenem
name that drug: Cubicin
daptomycin
name that drug: Tygacil
tigecycline
name that drug: Bactrim
trimethoprim/sulfamethoxazole
(TMP/SMX)
name that drug: Rocephin
ceftriaxone
name that drug: Avelox
moxifloxacin
name that drug: Zithromax
azithromycin
name that drug: Primaxim
imipenem/cilastatin
name that drug: Synercid
dalfopristin-quinupristin
name that drug: Cleocin
clindamycin
name that drug: Flagyl
metronidazole
augmentin: dosage(s)
500 or 875 mg PO BID
how much clavulonic acid is in Augmentin 500 mg?
Augmentin 875 mg?
both have 125 mg
augmentin: indication
PO antibiotic for outpatient therapy of polymicrobial infections
augmentin: spectrum of activity
- Staph (not MRSA)
- Strep
- Enterococci
- Gram negatives
- anaerobes
does augmentin cover pseudomonas?
no
zosyn: dosage(s)
- 3.375 g IV q6h
- Renal dose – 2.25 g IV q6h
- Alternate dose – 4.5 g IV q6h
zosyn: indication(s)
approved for use in adults for the treatment of moderate to severe diabetic foot infections
zosyn: spectrum of coverage
- Staph (not MRSA)
- Strep
- Enterococci
- Gram negatives
- anaerobes
does zosyn cover pseudomonas?
Yes!
unasyn: dosage(s)
- 3.0 IV q6h
- Renal dose – 1.5 g IV q6h
unasyn: indication(s)
empiric therapy for polymicrobial diabetic foot infections
unasyn: spectrum of activity
- Staph (not MRSA)
- Strep
- Enterococci
- Gram negatives
- anaerobes
does Unasyn cover pseudomonas?
No
what is an appropriate alternative to Unasyn for a patient with a Penicillin (PCN) allergy?
- Clinda/Cipro
- Levaquin
- (there are others)
timenten: dosage(s)
3.1 g IV q4-6h
timentin: indication(s)
broad spectrum antibiotic for polymicrobial infections
timentin: spectrum of activity
- Staph (not MRSA)
- Strep
- Gram negatives
- anaerobes
does timentin cover pseudomonas?
Yes!
what should you watch for when giving Timentin?
Increased Na+ (sodium) load
(5.2 meq/gram)
penicillins that cover pseudomonas?
- (4th and 5th generations)
- piperacillin, Zosyn
- ticarcillin, Timentin
- carbenicillin, mezlocillin, azlocillin
what are IV alternatives for PCN allergic patients?
- clindamycin
- vancomycin
- Levaquin
- Bactrim
how are penicillins (PCNs) excreted?
All are renally excreted, *except:
- mezlocillin
- azlocillin
- piperacillin
- (the ureidopenicillins are 20-30% renal)
what concern is there of a patient on both PCN and probenecid?
probenecid will increase duration of serum levels of PCN and most cephalosporins
what is the cross-reactivity of cephalosporins and PCN?
1-10%
(depending on whom you talk to)
are cephalosporins contraindicated for a patient with a PCN allergy?
- Many people will say yes, and according to Dr. Warren Joseph, “Cephalosporins should be avoided entirely in patients with a history of anaphylaxis to penicillin”
- However, he states that if there is a questionable allergy history (rash or upset stomach), “Cephalosporins can be used with little worry”
- Personally, I will give a cephalosporin to a patient with a PCN allergy if all he or she had was an upset stomach and I document this.
how to treat serious hospital-acquired Gram negative infections?
- 3rd generation cephalosporins
- aminoglycoside (i.e. Rocephin, gentamycin)
what is the coverage of cephalosporins for each class?
1st Generation
- Gram positive – Staph (not MRSA) and Strep
- Gram negative – Proteus, E. coli, Klebsiella, Salmonella, Shigella (PECKSS)
- Anaerobes – not Bacteroides
2nd Generation
- Gram positive – similar to 1st gen
- Gram negative – more coverage, H. influenza, Neisseria, Proteus, E. coli, Klebsiella, Salmonella, Shigella (HEN PECKSS)
3rd Generation
- Gram positive – less than 1st and 2nd gen
- Gram negative – expanded coverage, ceftazadime covers Pseudomonas
4th Generation
- Gram positive – similar to 1st gen
- Gram negative – similar to 3rd gen, including Pseudomonas
- No anaerobic coverage
what is the coverage of cephalosporins for 1st generation?
1st Generation
- Gram positive – Staph (not MRSA) and Strep
- Gram negative – Proteus, E. coli, Klebsiella, Salmonella, Shigella (PECKSS)
- Anaerobes – not Bacteroides
what is the coverage of cephalosporins for 2nd generation?
2nd Generation
- Gram positive – similar to 1st gen
- Gram negative – more coverage, H. influenza, Neisseria, Proteus, E. coli, Klebsiella, Salmonella, Shigella (HEN PECKSS)
what is the coverage of cephalosporins for 3rd generation?
3rd Generation
- Gram positive – less than 1st and 2nd gen
- Gram negative – expanded coverage, ceftazadime covers Pseudomonas
what is the coverage of cephalosporins for 4th generation?
4th Generation
- Gram positive – similar to 1st gen
- Gram negative – similar to 3rd gen, including Pseudomonas
- No anaerobic coverage
name a couple of cephalosporins for each generation
1st Generation – cefazolin (Ancef), cephalexin (Keflex)
2nd Generation – cefaclor (Ceclor), cefuroxime (Ceftin)
3rd Generation – ceftriaxone (Rocephin), ceftazidime (Fortaz), cefdinir (Omnicef)
4th Generation – cefepime (Maxipime)
cephalosporins: excretion
Renally, *EXCEPT for:
- ceftriaxone (renal/hepatic)
- cefoperazone (hepatic)
vancomycin: main indication
MRSA