Treatment approaches Flashcards
Asymptomatic bacteriuria
Positive urine cultures even if >100,000 CFU without presence of symptoms do not require antibiotic treatment unless the patient is pregnant or undergoing urinary surgery
Document as asymptomatic bacteriuria
Urinary tract infections
41% Proteus mirabilis and 28% E. coli strains are resistant to ciprofloxacin
consider alternative agent for empiric therapy
Skin and soft tissue infections
Clindamycin combination therapy only indicated in Group A Streptococcus infections
Purulent infections, moderate to severe: consider MRSA coverage with vancomycin
Non-purulent or diffuse-infections, mild to moderate: B-lactam (cefazolin) is preferred. Consider clindamycin as an allergic alternative
Avoid using TMP-SMX empirically due to lack of Streptococcus coverage
MSSA
Cefazolin (IV) or cqphalexin (PO) drugs of choice
Nafcillin is an alternative
51% MSSA are oxacillin sensitive
Enterococcal infections
Ampicillin (IV) or amoxicillin (PO) drugs of choice unless resistant
Adding a B-lactamase inhibitor (ampicillin/sulbactam or amoxicillin/clavulanate) does not add any benefit, as this is not the resistance mechanism of Enterococcus
Cephalosporins do not cover enterococcus
Extended-spectrum beta-lactamase producers (ESBLs)
Meropenem is preferred drug for ESBLs
6% of E. coli and 5% Klebsiella pneumoniae are ESBLs
Haemophillus influenzae and Moraxella catarrhalis
25% H. flu and 88% of M. catarrhalis are B-lactamase producing
Preferred therapy:
IV: ampicillin/sulbactam or ceftriaxone
PO: amoxicillin/clavulanate or cefuroxime
Candida infections
74% of Candida isolated from all sites is C. albicans
26% of Candida isolated in blood is C. albicans
Fluconazole drug of choice for C. albicans
For fungemia consider micafungin empirically and narrowing to fluconazole if C. albicans isolated
Micafungin is the echinocandin on formulary
Empiric antibiotic de-escalation if S. aureus not isolated
DC vancomycin
Empiric antibiotic de-escalation if resistant gram negative organisms are not isolated (Pseudomonas, Enterobacter)
De-escalate from zosyn or cefepime to ampicillin/sulbactam or ceftriaxone
Empiric antibiotic de-escalation if no isolate is identified or normal flora identified
De-escalate to an oral abx if patient is clinically stable to do so
Empiric antibiotic de-escalation if isolate is susceptible to a 1st gen cephalosporin
Do not use a 3rd generation cephalosporin (e.g. ceftriaxone), de-escalate to the narrowest spectrum (e.g. cefazolin (Ancef))
C. difficile
Mild to moderate: Metronidazole 500 mg PO q8 hr for 10-14 days
Severe: Vancomycin 125 mg PO q6 hrs for 10-14 days
Severe complicated: S/S of ileum, toxic megacolon, perforation, sepsis 2/2 CDI:
Metronidazole 500 mg IV q 8 hrs + Vancomycin 500 mg PO/NG q6 hrs +/- vancomycin 500 mg retention enema
Treat at least 14 days
Diabetic foot infections
Polymicrobial: b-hemolytic strep, S. aureus, Pseudomas, Gram-negative rods, Anaerobes
Ampicillin/sulbactam 3 gm IV q6 hrs
OR
If pseudomonas concern:
Piperacillin/tazobactam extended infusion 3.375 gm IV q 8 hrs (or 3.375 gm IV q6 hrs if facility uses traditional dosing)
+/- vancomycin 20-25 mg/kg load plus pharmacy to dose if MRSA concern
Duration: patient and pathogen dependent
Intra-abdominal infections
Abscess, cholecystitis, diverticulitis
Enterococcus, Enterobactericeae, anaerobes
Mild to moderate: Ceftriaxone 1 gm IV q24 hrs + Metronidazole 500 mg PO q12 hr
Severe: Piperacillin/Tazobactam extended infusion 3.375 gm IV q 8 hrs (or 3.375 gm IV q6 hrs if facility uses traditional dosing)
Duration:
After source control: 4-7 days
Abscess: varies based on patient response
Meningitis under 50 yo
S. pneumoniae, N. meningitides
Ceftriaxone 2 gm IV q 12 hrs + vancomycin (20-25 mg/kg load plus RX to dose)
+/- ampicillin 2 gm IV Q4 hrs if Listeria concern
Duration patient and pathogen dependent
Meningitis over 50 yo
S. pneumoniae, N. meningitides, Listeria
Ceftriaxone 2 gm IV q 12 hrs + vancomycin (20-25 mg/kg load plus RX to dose) + ampicillin 2 gm IV Q4 hrs
Duration patient and pathogen dependent
Neutropenic fever
S. epidermis, K. pneumoniae, P. aeruginosa, S. aureus, E. coli
Cefepime 2 gm IV Q8 hrs +/- Vancomycin (20-25 mg/kg load plus RX to dose)
Continue until neutropenia subsides (ANC >= 500) and afebrile or longer if clinically necessary depending on symptoms and pathogens
Community acquired pneumonia
S. pneumoniae
M. pneumoniae
C. pneumoniae
H. influenzae
Ceftriaxone 1 gm IV q 24 hrs + Azithromycin 500 mg IV/PO daily
Cephalosporin allergy:
Non-ICU: Levofloxacin 750 mg IV/PO q 24 hrs
ICU: Aztreonam 1 gm IV q8 hr + Levofloxacin 750 mg IV/PO q24 hrs
Duration: 5 days
Longer depending on symptoms and pathogens
Aspiration pneumonia
anaerobes
Ampicillin/sulbactam 3 gm IV q6 hrs
OR
Clindamycin 600 mg IV q8 hrs
or Metronidazole 500 mg IV q6 hr
+ Ceftriaxone 1 gm IV q24 hr or Levofloxacin 750 mg IV q24 hrs if cephalosporin allergy
Duration 5 days
Hospital acquired/ventilator acquired pneumonia
P. aeruginosa, K. pneumoniae, Acinetobacter, S. aureus (MRSA)
Cefepime 2 gm IV q8 hrs OR Zosyn 3.375 gm IV q 8 hr (or 4.5 gm IV q6 hr if traditional dosing used) OR Meropenem 1 g IV Q8 hrs
+ Vancomycin 20-25 mg/kg load plus RX to dose
+/- Tobramycin 7 mg/kg IV q24 hr OR Gentamicin 7 mg/kg IV q24 hr OR levofloxacin 750 mg IV daily OR cipro 400 mg IV q8 hrs*
*consider adding if patient has received IV abx therapy in preceding 90 days
Duration: 7 days
Septic joint
STD risk: N. gonorrhoeae, S. aureus, Streptococcus
Low STD risk: S. aureus
Ceftriaxone 1 g IV q24 hr + Vancomycin 20-25 mg/kg load plus RX to dose
+/- Azithromycin 1 gm PO once if STD risk to cover Chlamydia trachomatis
Duration: patient and pathogen dependent
Non-purulent cellulitis/erysipelas
B-hemolytic strep, S. aureus
Mild to mod: Cephazolin 1 gm IV q 8 hr OR Nafcillin 1 gm IV q 4 hr
Severe: Vancomycin 20-25 mg/kg load plus RX to dose + Piperacillin/Tazobactam extended infusion 3.375 gm IV q8 hrs (or 3.375 gm IV q6 hrs if traditional dosing used)
Uncomplicated: 5 days
Abscess/complicated: 7-10 days
Longer depending on symptoms and pathogens
Purulent/Abscess or Risk of MRSA (cellulitis)
S. aureus
Vancomycin 20-25 mg/kg load plus RX to dose
Uncomplicated: 5 days
Abscess/complicated: 7-10 days
Longer depending on symptoms and pathogens
Uncomplicated cystitis
E coli, Proteus, Klebsiella, Enterococcus
TMP-SMX 160/800 mg PO BID or Nitrofurantoin 100 mg PO BID or Cephalexin 500 mg PO q6 hrs if resistance or allergy
Duration: 3-5 days
Complicated cystitis
E coli, Proteus, Klebsiella, Enterococcus
Ampicillin 2 gm IV Q6 hrs + Gentamicin 5 mg/kg IV Q24 hr (or facility protocol) OR pipercillin/tazobactam extended infusion 3.375 gm IV Q8 hr (or 3.375 gm IV q6 hrs if traditional dosing used)
Duration 7-10 days
With structural abnormalities - 14 days
Pyelonephritis
E coli, Proteus, Klebsiella, Enterococcus
Ceftriaxone 1 gm IV q24 hrs
Duration: 14 days
