antibiotics Flashcards
What should you always consider before starting an antibiotic
1) what is the most likely infecting organism
2) Have a gram stain and Culture/ Staining done
3)Allergies
4)Kidney function (BUN and Cr)
5) Interactions
Augmentin
amoxacillin/ clavulonic acid
Zosyn
piperacillin/tazobactam
Unasyn
ampicillin/sulbactam
Timentin
Ticarcillin/clavulonic acid
Zyvox
linezolid
Invanz
ertapenem
Cubicin
daptomycin
Tygacil
Tigecycline
Bactrim
TMP/SMX
Rocephin
cetriaxone
Avelox
moxifloxacin
zithromax
azithromycin
primaxim
imipenem/cilastatin
synercid
dafopristin/quinupristin
Cleocin
clindamycin
flagyl
metronidazole
Dose of augmentin
500 or 875 mg PO BID
Amount of clavulonic acid in Augmentin 500mg and 875 mg
both have 125 mg
Spectrum of activity for augmentin
staph, strep, enterococci, gram negatives, anaerobes
What is the dose for Zosyn (3 alternatives)
3.375 g IV every 6 hours
Renal dose- 2.25g IV 6 hours
Alternate dose- 4.5g IV q6hours
Spectrum of action for zosyn
staph, strep, enterococci, gram negatives and anaerobes
COVERS PSEUDOMONAS
Unasyn dosing (2)
3.0 IV Q6
Renally- 1.5g IV q6
Unasyn indications
for polymicrobial diabetic foot infections
Spectrum of activity
Staph, strep, enteroccoci, gram negatives
Timentin dosing
3.1 g IV q4-6 hours
Timentin indications
broad spectrum antibiotic for polymicrobial infections
Spectrum for Timentin
Staph, strep, gram neg, anaerobes, COVERS PSEUDOMONAS
What lab value do you watch for with Timentin
increased NA loads
Penicillins that cover pseudomonas (9)
4th and 5th generation cephalosporins
Piperacillin
Zosyn
Ticaricillin
Timentin
Carbenicillin
Mezlocillin
Azlocillin
What are IV alternatives for PCN allergic patients (4)
clindamycin, vancomycin, levaquin, bactrim
How are PCN’s excreted
all are renally excreted except mezlocillin, azlocillin, piperacillin
What concern is there of a patient on PCN and probenecid
probenecid will increase duration of serum levels of PCN and most cephalosporins
Vancomycin dosing
1g IV q12hours with slow infusion
Vancomycin- when are levels drawn
peak taken 30 minutes after the 3rd dose
trough taken 30 minutes before the 4th dose
Vancomycin- what should the peaks and troughs be
peak: 15-30 mg/mL
Trough < 10mg/mL
How to adjust the dose based on peaks and troughs
If peak is too high decrease the dose
If the peak is too low increase the dose
If the trough is too high increase the interval between doses
If the trough is too low decrease the interval between doses
What happens when you infuse Vanco too quickly
Red Man syndrome- pruritis and erythema
How to decrease the risk of Red Man syndrome
slow infusion over one hour
How to treat Red Man syndrome
anti histamines until symptoms resolve
Other side effects of vancomycin
ototoxicity and nephrotoxicity
When should PO vancomycin be used and what is the dose
for treatment of pseudomembranous colitis
125mg PO q6 hours
What is the dose for bactrim
one tab PO BID
How much is in the single strength tablet of bactrim, and in the double strength
single strength- TMP 80mg/SMX 400mg
double strength- TMP 160mg/ SMX-800mg
Does Bactrim cover pseudomonas
NO
Contraindications with bactrim
patient on oral hypoglycemic or with G6PD deficiencies
Zithromax dosing
250mg PO
Half life of zithromax
68hours
Can zithromax be given with a PCN allergy
yes
Dosing for Primaxin
500mg IV q6-8
OR
1 gram q6-8
Does Primaxin cover MRSA or Pseudomonas
no and no
What is a side effect of primaxin
seizures in patients with a history of seizures
risk of seizure increases with the dosing
How does primaxin work. (the individual parts)
imipenem is the antibiotic portion
cilastatin is the renal dehydropeptidase inhibitor which prevents imipenem from being metabolized by the kidneys
Which antibiotic is nicknamed gorrilamycin
imipenem
Invanz dosing
1g IV q24 hours
indications for Invanz
approved for use in adults for treatment of moderate to severe diabetic foot infections
What class is Invanz
it is a structural unique 1 beta methyl carbapenem related to Beta-lactam
What is the dose for Zyvox
400-600mg PO/IV q12 hours
indication for Zyvox
oral Zyvox used for outpatient treatment of MRSA infections
Major side effect for Zyvox
thrombocytopenia
Dose for cipro (2)
250-750mg PO q 12 hours
200-400mg IV q 12 hours
Levaquin dosing
250-500mg PO/IV q24 hours
Dose for avelox (moxifloxacin)
400mg PO/IV q24 hours
Spectrum of activity
good for pseudomonas
Cipro- limited gram positive
Levaquin and Avelox- better for gram positives
Who should not be given a quinolone
children with open growth plates. May have risk of cartilage degeneration
Aztreonam dosing
1-2grams IV q8 hours
aztreonam spectrum of activity
gram negatives and pseudomonas
Aztreonam side effects
none
What are the aminoglycosides (3)
Gentamycin, Tobramycin and Amikacin
Spectrum of activity for aminoglycosides
Gram negative anaerobes
Side effects for aminoglycosides
Ototoxicity- irreversible
Nephrotoxicity- reversible
Neuromuscular blockade- prevented with slow infusion
Clindamycin dosing
600-900mg IV q8hours OR
150-300mg PO BID
Spectrum of activity for clindamycin
most gram positives and most anaerobes
What is a side effect of clindamycin
pseudomembranous colitis
How is clindamycin metabolized
by the liver
Flagyl dosing
500 mg PO TID
spectrum of activity for flagyl
some gram positive anaerobes and most gram negative anarobes
What antibiotics cover MRSA
PO-4
IV-8
Topical- 1
PO-Linezolid, minocycline, cipro/rifampin, bactrim/rifampin
IV- Vancomycin, linezolid, minocyclin, cipro/rifampin, bactrim/rifampin, synercid, tigecyclin and telavancin
Topical- Bactroban
What are the only FDA approved drugs for treating MRSA
Vancomycin
Linezolid
Daptomycin
Tigecyclin
Telavancin
How do you treat VRE
(2)
Linezolid
Dalfopristin-quinupristin
What is the only PO therapy for VRE
Linezolid
What drugs cover Pseudomonas
Cipro
Ceftazidime, Cefepime
Aztreonam
Aminoglycosides
Timentin
Zosyn
What are some empiric therapies for polymicrobial foot infections
Vanco/Zosyn
Clinda/Cipro
Vanco/Invanz
What are the only FDA approved drugs for treating diabetic foot infections
3 Z’s
Zosyn
Zyvox
Invanz
2 main causes of antibiotic associated diarrhea
Pseudomembranous colitis-Cdif
Non-specific colitis: staph aureus
How to test for C-dif
check stool for C diff
What is the most common cause of C-dif colitis
clindamycin
How do you treat c-dif colitis
Vanco- 125mg PO q6
Flagyl 500mg PO TID
What antibiotics are metabolized by the liver
3C’s and 1 E
Clindamycin
Cefoperazone
Chloramphenicol
Erythromycin
Can antibiiotics affect PT/INR
yes antibiotics can affect normal flora, which can alter Vitamin K levels.
PT INR can increase
What can Beta lactams cause
leukopenia
What is the MOA of aminoglycosides and Macrolides
Aminoglycosides inhibit 30S ribosomes
Macrolides inhibit 50S ribosomes
A boy at 30 will not become a Man until 50
What antibiotics can be safely used with PMMA beads
Vancomycin
Gentamycin
Tobramycin
Cefazolin
The curing of PMMA is exothermic, therefore the antibiotic must not be heat labile
What open fractures should be treated with antibiotics
Grade 2 and 3
Postoperative Day 1-2 source of fever (4)
“Wind”
everything with the lungs
-pneumonia
-aspirations
-pulmonary embolisms
-atelectasis
Postoperative Day 3-5 source of fever
“Water”
-urinary tract infection
Postoperative Day 5-7 source of fever
“wound”
-infection of the actual surgical incision
Postoperative day 5+ source of fever
“walk”
-deep vein thrombosis/ PE
Anytime postoperative source of fever
“wonder drugs”
drug fever reaction to blood products
DOC for clostridium perfringens
-12 million units of Penicillin G
Penicillins that are hepatically cleared(4)
Nafcillin, Mezlocillin, Azlocillin and Piperacillin
Anti-anaerobic antibiotics (2)
Clindamycin and Metronidazole
Anti-pseudomonal drugs (5)
-Maxipime
-Ciprofloxacin
-Avelox
-Tobramycin
-Timentin
What to give PO for mild MSSA infection
Keflex
What to give IV for mild MSSA infection
Ancef
What to give for moderate MSSA infection
Unasyn
What to give PO for Mild infection of MSSA+anerobes
Augmentin
What to give for moderate infection of MSSA+ anaerobes
ertapenem
What to give for moderate infection of MSSA+ ESBL
Imipenem/Cilastatin
What to give PO for mild MRSA infection (4)
-doxycycline
-daptomycin
-Bactrim
-Clindamycin (300mg)
What to give IV for mild MRSA infection
-Clindamycin( 900mg)
What to give for moderate MRSA infection
Linezolid and vancomycin
What to give for mild and moderate pseudomonas infection
piperacillin
What to give for a MRSA+ pseudomonas infection
-Vanco and Zosyn
-Cipro and clindamycin
What to give for a patient who has recurring infections but has used antibiotics recently
-try to cover for gram negative bacilli
—–fluoroquniolones or aminoglycosides