3. A Balancing Act
Appropriate initial
antibiotic while improving
patient outcomes and
heathcare
Unnecessary
antibiotics and adverse
patient outcomes and
increased cost
4. Empiric
Initial administration of a broad-spectrum antibiotic regimen
that attempts to improve outcomes and minimize resistance.
Defined orTargeted
Modification of antimicrobial therapy once the cause of
infection is identified.Therapy may also be discontinued if the
diagnosis of infection becomes unlikely.1
Focus on de-escalation of antibiotic therapy with the goal of
minimizing resistance and toxicity, and improving cost-
effectiveness.2,3
1. Kollef MH. Drugs. 2003;63:2157–2168.
2. Kollef MH. Crit Care Med. 2001;29:1473–1475.
3. Evans RS et al. N Engl J Med. 1998;338:232–238.
5. Enterococcus
S. aureus
Klebsiella spp.
Acinetobacter
P. aeruginosa
Enterobacter spp.
Boucher H, et al, Clin Infect Dis 2009;48:1-12
6. Antimicrobial stewardship involves the optimal
selection, dose and duration of an antibiotic
resulting in the cure or prevention of infection
with minimal unintended consequences to the
patient including emergence of resistance,
adverse drug events, and cost.
Dellit TH, et al. CID 2007;44:159-77,
Hand K, et al. Hospital Pharmacist 2004;11:459-64
Paskovaty A, et al IJAA 2005;25:1-10
Simonsen GS, et al Bull WHO 2004;82:928-34
Ultimate goal is improved patient care and
healthcare outcomes
9. Antimicrobial Resistance: Patients and hospitals in
Peril
The Clinical Consequences of Antimicrobial
Resistance
Transmission Control to Prevent the Spread of
MDROs in Health Care Facilities
Antimicrobial Stewardship
10
Joint Commission Resources 2009
11. Prospective audit with intervention and feedback
Formulary restriction and preauthorization
Supplemental Strategies
Education, guidelines, clinical pathways
Dose optimization via PK-PD
De-escalation/Streamlining
Antimicrobial order forms/order sets if CPOE
IV-PO switch
Computerized decision support
Others
Dellit TH, et al. CID 2007;44:159-77
Hand K, et al Hospital Pharmacist 2004;11:459-64
Paskovaty A, et al IJAA 2005;25:1-10
12. Prospective audit
system
Stewardship program
Outcomes
▪ Reason for treatment,
cultures, empirical, and
de-escalation
▪ LOS, mortality, and
% interventions
accepted
13
Toth NR, et al Am J Health-Syst Pharm 2010;67:747-9
IV to Oral interchange
13. Sentri7
SafetySurveillor
TheraDoc
Computerized physician order entry
Benchmarking and local antimicrobials point
prevalence surveys (state may consider doing
this)
Claridge JA, et al. Surg Infect 2010;11:125-31
17. Antimicrobial therapy of established infection
should be limited to 4–7 days, unless it is difficult to
achieve adequate source control
Bowel injuries due to penetrating, blunt, or
iatrogenic trauma repaired within 12 h and any
other intraoperative contamination of the operative
field by enteric contents should be treated with
antibiotics for <24 hours
Lack of evidence of infections includes, being afebrile, have normal WBC,
and tolerating an oral diet.
18. Biomarkers
Procalcitonin
CRP
PNA FISH
PCR
E-test of patient samples
19
Lawrence KL, et al. Am J Respir Crit Care Med 2009;198:434-8
Cals JWL, et al. Ann Fam Med 2010;8:124-33
Schuetz R, et al. JAMA 2009;302:1059-66
Bouza E, et al CID 2007;44:382-7
19. Antimicrobial usage
Days of therapy
Appropriateness of treatment
Antimicrobial cost
Bacterial susceptibilities
Patient outcomes
Antimicrobial adverse events
Acceptance of recommendations
Prescribers surveys
20
23. Provide advice on some of the practical
aspects of starting a new stewardship program
or expanding an existing program, with special
commentary regarding the unique challenges
facing community and teaching institutions.
24
24. The members of the team have to fit the
personal available
Staff physician with ID interest
P&T chair or committee member
Hospitalist with interest in ID
Non–ID-trained clinical pharmacist
Staff pharmacists (with certification in stewardship)
25
25. Performing selected stewardship activities
should be considered successful
Helping patients is the goal, not struggling to follow
guidelines at the expensive to a successful program
for your institution
Lines of authority and reporting are key
Quality and Safety
P&T for assistance with P&P and protocol approval
26
26. Outcome Metrics
CMS outcomes (CABP and SCIP)
Percentage of appropriate IV to PO
Point prevalence of antimicrobial use
Percent of appropriate antimicrobial regimens
Percent of patients withVAP orABSSTI treat according to
protocol (antimicrobial and non-antimicrobial metrics)
Antibiogram changes over time
Process Metrics
Percent of recommendations accepted (numbers and type)
CMS outcomes
27
27. Challenges faced by Community Hospitals
Lack of sufficient resources
▪ Private ID or NO ID physicians (or those that do not
want to be involved)
▪ ID pharmacist
▪ No extra staff (especially pharmacy)
▪ On site laboratory forC&S data
▪ Antibiograms which include non-formulary agents
▪ No IT systems for data gathering or analysis
▪ Dealing with non-compliant prescribers
▪ Embrace use of non-traditional stewardship personnel
28
28. One the program is approved the following should be
determined
What activities will be performed?
By which person?
How frequently?
With what authority?
What is the time line for reporting the data?
Advertise, market and educate direct care providers about the
programs (think grass roots politics)
Notify clinicians about changes that impact the program
Report program successes and failures
Share data with individual prescribers /departments when
possible 29
31. Provide descriptors of antimicrobial activity profiles
Provide surrogate markers to predict drug activity
Integrate “bug” and “drug” data
Host
Pathogen
Antimicrobial PK/PD
32. β-lactams
“not much happens until an adequate proportion
of PBP are occupied”
Smaller doses, more frequently
Prolonged or continuous infusion
Time>MIC
Aminoglycosides/Fluoroquinolones
AUC:MIC
Cmax/MIC
Dose AND MIC matter
33
33. β-lactams (stasis and near maximal killing)
Cephalosporins: 35% and 65%
Carbapenems: 20% and 40%
Penicillins: 30% and 50%
Fluoroquinolones (stasis and near maximal killing)
AUC/MIC: 20-25 and 250-300
Ambrose et al in CABP: 30 needed for clinical cure
HAP/VAP: AUC/MIC for levofloxacin 87 need for micro cure
34
36. Best represented by
Time>MIC
OptimalTime>MIC
varies
Usually at least 40% of
dosing interval
>50% in neutropenia
Time
Concentration
MIC
Time>MIC
37. Best represented by
Cmax:MIC ratio
Cmax:MIC ratio >8-12
associated with clinical
success
Optimal ratio varies
with drug and
organism
Time
Concentration
MIC
Cmax:MIC
38. Dose-fractionation experiment with lomefloxacin in an animal model
Same total dose given as different regimens
80mg/kg q24h
40mg/kg q12h
20mg/kg q6h
Control
Lode, et al. Clin Inf Dis 1998;27:33-9
39. Varies by particular isolate of organism
“Same drug, different bug”
Ex. Ciprofloxacin vs. Pseudomonas
Time
Concentration
AUC/
MIC MIC
MIC<1 mcg/mL
MIC=4 mcg/mL
AUC/
MIC
Cipro-sensitive Cipro-resistant
40. Traditional pharmacokinetic parameter
Calculated based on total serum
concentrations of drug
Obtained by sampling at multiple time points and
integrating under curve
Time
Concentration
41. Surrogate for AUC of unbound drug at site of
infection…at receptor site
Does not account for susceptibility of organism
Difficult to measure in clinical practice
Protein Binding Entry into infected site Access to bacterial target
Assayed Effective
42. Dudley & Ambrose. Curr Opin Microbiol 2000;3:515−521
Random
pharmacokinetics
and MIC values
from dataset
Plot results in
a probability chart
Calculate
pharmacodynamic
parameter
AUC MIC
AUC:MIC
43. Monte Carlo simulation
determine distribution of antimicrobial potency
(eg MIC distribution)
determine distribution of antimicrobial exposures
(eg AUCs)
computer program randomly selects parameters from
each of the distributions (500, 5000… iterations =
patients) and the probability distribution of achieving
the preset level (pharmacodynamic target attainment =
specific AUC:MIC orT>MIC) is computed
Nicolau & Ambrose. Am J Med 2001;111(9A):13S–18S
44. May be a better surrogate marker of activity than drug
exposure (AUC) or MIC alone
Studies have shown AUC/MIC to be predictive of antimicrobial
activity
Probability of developing
resistance during
treatment for nosocomial
pneumonia
Thomas, et al. Antimicrob Agents Chemo 1998;42:521-7.
45. Gram-positive anaerobic bacteria
Exotoxin producing
Fecal-oral transmission
C. difficile infection (CDI) onset median 2-3 days
Most common cause of infectious diarrhea
20-30% of antibiotic-associated diarrhea
1. Infect Control Hosp Epidemiol. 2010; 31(5): 431-55.
2. Centers for Disease Control and Prevention
46. Sunenshine et al. Cleve Clin J Med. 2006;73:187-97.
4. Toxin A & B Production
leads to colon damage
+/- pseudomembrane
1. Ingestion
of spores transmitted
from other patients
via the hands of healthcare
personnel and environment
2. Germination into
growing (vegetative)
form
3. Altered lower intestine flora
(due to antimicrobial use) allows
proliferation of
C. difficile in colon
48. Diarrhea
3 or more unformed stools
Positive stool test
Enzyme immunoassay vs. polymerase chain
reaction
Pseudomembranous colitis
Colonoscopic or histopathologic findings
1. Infect Control Hosp Epidemiol. 2010; 31(5): 431-55.
49. Clinical definition Supportive clinical data
Mild or moderate WBC less than 15,000 AND SCr less
than 1.5 times premorbid level
Severe WBC greater than 15,000 OR SCr
greater than 1.5 times premorbid
level
Severe, complicated Hypotension, shock, ileus, megacolon
1. Infect Control Hosp Epidemiol. 2010; 31(5): 431-55.
50. Discontinue any potential causative agent
Immediately initiate empirical treatment
Severe or complicated
Data of probiotic usage is inconclusive
Not recommended for primary prophylaxis
1. Infect Control Hosp Epidemiol. 2010; 31(5): 431-55.
51. Initial Episodes RecommendedTreatment
Mild or moderate Metronidazole 500 mg PO
TID for 10-14 days
Severe Vancomycin 125 mg PO QID
for 10-14 days
Severe, complicated Vancomycin 500 mg PO QID
plus metronidazole 500 mg
IV Q8H
1. Infect Control Hosp Epidemiol. 2010; 31(5): 431-55.
52. Recurrent Infection Recommended
Treatment
First recurrence Same as initial episode
Second recurrence Vancomycin tapered
and/or pulsed
1. Infect Control Hosp Epidemiol. 2010; 31(5): 431-55.
53. Prospective, randomized, double-blind,
placebo- controlled trial
150 patients completed study
Stratified patients: mild or severe
Compared metronidazole 250 mg PO QID to
vancomycin 125 mg PO QID for 10 days
3. Clinic Infect Dis. 2007; 45:302-7.
55. Treatment failures with both metronidazole
and vancomycin
Increasing rates of recurrence with both
vancomycin and metronidazole
Risk ofVRE colonization with both agents
ADRs with current treatments especially,
metronidazole
56. Macrocycles, a new class of antibacterials for oral
administration
Bactericidal against C. difficile, with a PAE of 6-10 hrs
Inhibits RNA synthesis by RNA polymerases
Fecal concentration are 5000 times the MIC90 of C difficile
isolates
Preservation of the microbiota of the GI tract compared with
vancomycin
Minimal systemic absorption measured in the ng/ml range
Food does increase systemic absorption but increased serum
concentration is NOT clinically significant
Clinical resistance has been observed in the lab and in one
treated patient (MIC from 0.06 to 6 mcg/ml)
Louie T, et al. AAC 2009;53:223-28
Product Label Dificid 2011
58. Inclusion Criteria:
Adult patients (> 16 y.o.) with a diagnosis of C. difficile
infection
▪ Presence of diarrhea: a change in bowel habits, > 3 unformed bowel
movements in the 24-hour period before randomization
▪ C dif.Toxin A, B, or both in a stool specimen obtained 48 hours
before randomization
Exclusion Criteria:
Received: oral bacitracin, fusidic acid, or rifaximin
Life-threatening of fulminant C. dif infection, toxic
megacolon, previous exposure to fidaxomicin, a history of
ulcerative colitis or Crohn’s disease, or > 1 occurrence of C.
difficile infection within 3 months before the start of the
study were excluded
59. Clinical Cure: resolution of diarrhea with maintenance of
resolution for duration of therapy and no further Rx
Clinical failure: persistence of diarrhea, need for additional Rx,
or both
Global cure: resolution of diarrhea without recurrence
Clinical recurrence: If subjects remained in study and had a
follow up assessment at day 36-40, after randomization they
were evaluated for recurrence. Defined as reappearance of
diarrhea within 4 weeks after stopping study medication, +
toxin assay, and need for treatment
60.
61.
62. Subgroup MITT Fidax MITT
Vanco
PP
Fidax
PP
Vanco
Age ≥ 65 years 103/122 (84.4) 131/152 (86.2) 99/113 (87.6) 122/138 (88.4)
Inpatient 136/167 (81.4) 146/187 (78.1) 128/146 (87.7) 136/162 (84)
No Previous
episode of CDI
211/239 (88.3) 217/255 (85.1) 203/222 (91.4) 209/235 (88.9)
NAP1/BI/027 59/75 (78.7) 7/83 (80.7) 56/65 (86.2) 61/72 (84.7)
Non
NAP1/BI/027
117/125 (93.6) 121/132 (91.7) 115/119 (96.6) 119/126 (94.4)
Concurrent
Systemic ABX
67/83 (80.7) 72/94 (76.6) 63/71 (88.7) 67/80 (83.8)
Moderate CDI 102/111 (91.9) 88/106 (83) 99/105 (94.3) 84/97 (86.6)
Severe CDI 92/112 (82.1) 109/123 (88.6) 89/101 (88.1) 107/115 (93)
No differences between the groups were significant
Number/total number (percent)
64. Commercially available test in the world to detect and differentiate
the epidemic strain of C. difficile (027/NAP1/BI).
• With rapid and accurate identification of epidemic strain,
Infection Control professional can stay ahead of potential
outbreak situation.
Innovative multiplex design enables detection of C. difficile
Infection (CDI) and 027/NAP1/BI strain call-out in a single
cartridge
• Cepheid’s Xpert C. difficile/Epi is a real time PCR test that runs on
the GeneXpert system
• GeneXpert system is the first to fully automate and integrate all
the steps required for PCR-based DNA testing: sample
preparation, DNA amplification and detection
65. Vancomycin PO capsules 125 mg Q6h x 10 days
▪ Red bookAWP $31.82 per capsule
▪ $1275 per course
▪ Inpatient, a vancomycin slurry is made by pharmacy for
treatment of CDI
▪ Outpatient, capsules are dispensed and covered by payors
▪ Patient assistance program for POVancomycin
Metronidazole 500 mg PO Q8h x 10 days
▪ Red bookAWP $1.38
▪ $41.40 per course
Fidaxomicin 200 mg PO Q12h x 10 days
▪ Reported cost of $2800
68. Why the changes?
Better PKPD data and knowledge about resistance
mechanism especially ESBLs ± AmpC
What were they based upon?
Mostly PD, expert opinion and a few case series.
How does the change impact treatment?
May use any agent based on the observed MIC result
and pts factors, carbapenem are not always needed
How does it impact reporting of ESBL?
Susceptibility of cephalosporins should NOT be
changed if identified as an ESBLs 69
70. Some ESBL producing isolates are susceptible in-
vitro
Poor outcomes in patients with infections due to
ESBLs cephs
Bacteria often have ESBLs and AmpC-like enzymes
No need for ESBL testing or confirmatory test with
new breakpoints.
Hospitals using FDA-approvedAST devices can
utilize existing FDA interpretive breakpoints
Either FDA or CLSI susceptibility interpretive
breakpoints are acceptable to accrediting bodies.