The Essential Role of Senior Care Pharmacists in Antimicrobial Stewardship: An Updated Position Statement on Behalf of the American Society of Consultant Pharmacists and the Society of Infectious Diseases Pharmacists

Senior care pharmacists are well-positioned to lead and drive antimicrobial stewardship (AMS) initiatives, not only through audit and data collection, but also through communication, collaboration, and cooperation with prescribers and nurses to influence prescribing behaviors. Senior care pharmacists are in a unique position to take a leadership role within the interprofessional team to achieve AMS goals. They should engage with the interprofessional team to promote the judicious and appropriate use of antimicrobials at their practice sites. This position statement is an update of the 2017 version by the American Society of Consultant Pharmacists (ASCP) Antimicrobial Stewardship and Infection and Prevention Control Committee and the Society of Infectious Diseases Pharmacists (SIDP).

Antimicrobials in Animal Agriculture in the United States: A Multidisciplinary Overview of Regulation and Utilization to Foster Collaboration: On Behalf Of the Society of Infectious Diseases Pharmacists

Given the complexity of antimicrobial resistance and the dire implications of misusing antimicrobials, it is imperative to identify accurate and meaningful ways to understand and communicate the realities, challenges, and opportunities associated with antimicrobial utilization and measurement in all sectors, including in animal agriculture. The objectives of this article are to (i) describe how antimicrobials are regulated and used in US animal agriculture and (ii) highlight realities, challenges, and opportunities to foster multidisciplinary understanding of the common goal of responsible antimicrobial use. Recognition of the realities of medicine, practice, and policy in the agricultural setting is critical to identify realistic opportunities for improvement and collaboration.

Examining the combination of cefixime and amoxicillin/clavulanate against extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli isolates

INTRODUCTION

Community-acquired urinary tract infections (UTIs) caused by extended spectrum beta-lactamase (ESBL)-producing Escherichia coli have limited oral therapeutic options and pose significant clinical challenges. The goal of this study was to evaluate the in vitro synergy between CFM and AMC against ESBL E. coli with aims to identify an oral treatment option for UTIs.

METHODS

Minimum inhibitory concentrations (MICs) of CFM in the presence of AMC were determined for 46 clinical isolates by placing a CFM Etest on a plate with AMC impregnated in the agar. Isolates with CFM MIC ≤1 µg/ml in the presence of AMC were considered susceptible to the CFM and AMC combination. Five isolates were then selected for further testing using time-kill analysis in the presence of CFM, AMC, and CFM with AMC. Time-kill curves were plotted to determine synergy over 24 hours.

RESULTS

AMC improved the activity of CFM against ESBL E. coli isolates by 128-fold in the Etest analysis with 85% of tested isolates being susceptible to the combination. Four-fold or greater reduction in CFM MIC was exhibited in 44 of 46 (96%) isolates when in the presence of AMC. Synergy and bactericidal activity between CFM and AMC were exhibited in each of the five isolates tested by time-kill analysis.

DISCUSSION/CONCLUSION

This study found that AMC improves the activity of CFM against ESBL E. coli and that this antibiotic combination has potential as an oral therapeutic option to treat ESBL E. coli UTIs.

Approaching 65 Years: Is it Time to Consider Retirement of Vancomycin for Treating Methicillin-Resistant Staphylococcus aureus Endovascular Infections?

Vancomycin was introduced nearly 65 years ago and remains the standard antibiotic for serious methicillin-resistant Staphylococcus aureus (MRSA) infections. Staphylococcus aureus remains highly susceptibility to vancomycin (>97%). Despite this, MRSA treatment failure with vancomycin is high in complicated bacteremia. Additionally, vancomycin can cause nephrotoxicity, leading to new therapeutic drug monitoring guidance. This demonstrates how difficult it is to dose vancomycin in a way that is both efficacious and safe, especially during long courses of therapy. Often underappreciated are the cost, resources, and complexity of vancomycin care at a time when alternative antibiotics are becoming cost comparable. This perspective highlights a bigger picture of how the treatment repertoires of many other diseases have changed and advanced since vancomycin’s introduction in the 1950s, yet the vancomycin MRSA treatment standard remains. While vancomycin can still have a role, 65 years may be a practical retirement age for vancomycin in highly complex endovascular infections.

Long-Acting Lipoglycopeptides Can Interfere With Vancomycin Therapeutic Drug Monitoring

Oritavancin and dalbavancin are long-acting lipoglycopeptides with activity against susceptible gram-positive bacteria, including methicillin-resistant Staphylococcus aureus. Though similar in structure to traditional glycopeptide antibiotics like vancomycin, these antibiotics have terminal half-lives >10 days, and, as a result, there is potential for administration of vancomycin to a patient while oritavancin or dalbavancin are still appreciably present in serum. Given the structural similarities, this creates an opportunity for lab assay interference when performing therapeutic drug monitoring for vancomycin. Following higher-than-expected serum vancomycin concentrations in a patient who received both oritavancin and vancomycin within a short time frame, we evaluated the potential for lipoglycopeptide interference with clinical vancomycin assays. Five platforms covering 3 immunoassay technologies were used to quantify vancomycin concentrations in serum spiked with oritavancin or dalbavancin. Oritavancin generated spurious vancomycin concentrations (20%-84% increase) in both enzyme-multiplied immunoassay technique and a particle-enhanced turbidimetric inhibition immunoassay. However, the improper detection of oritavancin was not consistent across all particle-enhanced turbidimetric inhibition immunoassay platforms. Dalbavancin interference was not detected on any of the platforms tested. The interference from oritavancin may result in falsely elevated vancomycin concentrations and, subsequently, inappropriately adjusted vancomycin doses.

Vancomycin Advanced Therapeutic Drug Monitoring: Exercise in Futility or Virtuous Endeavor to Improve Drug Efficacy and Safety?

Vancomycin is commonly prescribed to hospitalized patients. Decades of pharmacokinetic/pharmacodynamic research culminated in recommendations to monitor the ratio of the area under the concentration-time curve (AUC) to the minimum inhibitory concentration in order to optimize vancomycin exposure and minimize toxicity in the revised 2020 guidelines. These guideline recommendations are based on limited data without high-quality evidence and limitations in strength. Despite considerable effort placed on vancomycin therapeutic drug monitoring (TDM), clinicians should recognize that the majority of vancomycin use is empiric. Most patients prescribed empiric vancomycin do not require it beyond a few days. For these patients, AUC determinations during the initial days of vancomycin exposure are futile. This added workload may detract from high-level patient care activities. Loading doses likely achieve AUC targets, so AUC monitoring after a loading dose is largely unnecessary for broad application. The excessive vancomycin TDM for decades has been propagated with limitations in evidence, and it should raise caution on contemporary vancomycin TDM recommendations.

621. Reporting Behaviors and Perceptions Towards the National Healthcare Safety Network Antimicrobial Use (AU) and Antimicrobial Resistance (AR) Options

Background

Antibiotic use (AU) and antibiotic resistance (AR; AUR) reporting to National Healthcare Safety Network (NHSN) is suboptimal by US hospitals. The Society of Infectious Diseases Pharmacists (SIDP) and the Society for Healthcare Epidemiology of America (SHEA) conducted a survey of their membership to 1) Identify characteristics of US health systems that report AUR data 2) Determine how NHSN AUR data are used by health systems and 3) Identify barriers to AUR reporting.

Methods

An anonymous survey was posted on SurveyMonkey from 1/21- 2/21/2020 and links were emailed to SIDP and SHEA Research Network members. Data were analyzed in Excel and RStudio. Respondent and hospital data were reported as frequencies and percentages. Fisher’s Exact test was used to compare survey responses from NHSN AUR reporters to non-reporters.

Results

A total of 238 individuals from 43 states responded to our survey. Respondents were primarily pharmacists (84%), from urban (45%), non-profit medical centers (80%) with >250 beds (65%). 62% of respondents reported to the AU option while 19% reported to the AR option. Respondents not using software for local AU or AR tracking were less likely than those using any software for local tracking to report to AU (19% vs 64%) and AR (2% vs 30%) options (P< 0.0001). Among AU and AR reporters 41% and 54% used clinical decision support software to aggregate compile data for upload while 54% and 38% used their electronic health record, and 5% and 8% used another method. Over half of AU (56%) and AR (51%) reporters upload data manually. Regular use of the NHSN data analysis tools was reported by 36% and 9% of those reporting AU and AR data respectively. The most common barriers to reporting were related to technical issues (software, IT support, data formatting) and time/salary support. Among non-reporters, increased expectations to report and better software solutions were most commonly identified as the best ways to increase reporting.

Conclusion

Efforts to improve AUR reporting should focus on software solutions and increasing the utility of AUR analytical tools. Increasing expectations to report may also help to improve reporting rates. The lower rate of AR vs AU reporting suggests that interventions should also target the AR option.

Disclosures

Brian J. Werth, PharmD, Shionogi Inc. (Grant/Research Support) Kerry LaPlante, PharmD, Merck (Advisor or Review Panel member, Research Grant or Support)Ocean Spray Cranberries, Inc. (Research Grant or Support)Pfizer Pharmaceuticals (Research Grant or Support)Shionogi, Inc. (Research Grant or Support)

Impact of a Systematic Pharmacist-Initiated Antibiotic Time-Out Intervention for Hospitalized Adults

INTRODUCTION

Antibiotic time-outs (ATO) are a recommended antimicrobial stewardship action, but data assessing their impact are lacking. This study investigated the impact of a systematic, pharmacist initiated ATO intervention.

METHODS

This pre-post study included inpatients on hospitalist and intensivist services receiving empiric antibiotics for ≥48 hours. The ATO was initiated by pharmacists after 48 hours of empiric therapy and the outcome was documented including antibiotic indication, plan, and duration. An electronic medical record (EMR) alert facilitated ATO completion and pharmacists and prescribers received education prior to implementation. The primary outcome was EMR documentation of an antibiotic plan by 72 hours. Secondary outcomes included antibiotic utilization and antibiotic therapy modifications by 2 hours.

RESULTS

399 patients were included, 199 pre- and 200 post-intervention. The most common indications were pneumonia (32%), intra-abdominal infection (20%) and urinary tract infection (19%), with no between-group differences. EMR documentation of an antibiotic plan significantly improved in the post-intervention group (19% vs. 79%, p<0.0001) as did modifications to antibiotic therapy. The median duration of in-hospital antibiotic therapy was similar between groups (4.0 vs. 4.0 days, p = 0.2499). Approximately 45% of patients in each group received discharge antibiotics and median duration of discharge antibiotic therapy prescribed was reduced (7 vs. 5 days in the pre- and post-intervention groups, respectively; p = 0.0140).

DISCUSSION

Implementation of pharmacist initiated ATO was associated with improvements in supporting EMR documentation and antibiotic therapy modifications. These findings highlight an important role in which pharmacists can serve as part of a collaborative antibiotic stewardship team.

Exploring the Role of Piperacillin and Tazobactam in Combination with Vancomycin against Methicillin-Resistant Staphylococcus aureus

Previous studies have demonstrated synergy between piperacillin (PIP)-tazobactam (TAZ) (TZP) and vancomycin (VAN) against methicillin-resistant Staphylococcus aureus (MRSA). However, it is unknown whether PIP and/or TAZ synergizes with VAN against MRSA. We sought to determine whether PIP and/or TAZ synergizes with VAN against MRSA in vitro. The activity of PIP and/or TAZ with and without VAN (1/2 the minimum inhibitory concentration) was tested against 5 clinical MRSA isolates using a 24-h time-kill methodology. Antibiotic susceptibilities, accessory gene regulator (agr) operon functionality, and US strain type were also determined for the isolates. The combination of VAN and TZP was bactericidal against 3/5 isolates and synergistic against 4/5 isolates tested. Neither PIP nor TAZ alone combined with VAN demonstrated a significant reduction in bacterial growth. The combination of TZP and VAN was less active against the lone isolate with agr dysfunction. In summation, the combination of VAN with both PIP and TAZ was required for synergy against MRSA. This antibiotic combination may not be effective against unique MRSA strain types.

2082. Evaluation of Outpatient Parenteral Antimicrobial Therapy (OPAT) Processes and Outcomes Among Patients Within an Integrated Health System

Background

Successful management of outpatient parenteral antimicrobial therapy (OPAT) optimizes outcomes and reduces cost. We examined (i) local OPAT processes and outcomes, (ii) whether OPAT constraints favoring once daily antibiotics promoted suboptimal therapeutic choices, and (iii) whether these data could drive OPAT improvements.

Methods

Patients ≥ 18 years of age who received > 48 hours of OPAT at five infusion centers within a single health-system from January 1, 2018 to March 1, 2018 were eligible for review. The following patient- and treatment-level data were collected: age, gender, drug allergies, laboratory studies and frequency, OPAT indication, infection source, pathogen(s), antibiotic sensitivities, antibiotic therapy and duration, electronic order set used, prescriber specialty, evidence of failed prior oral or intravenous (IV) therapy and IV access type. The primary outcome was OPAT success: the clinical resolution of the infection without relapse within 30 days of antibiotic therapy completion. Secondary outcomes included change in antibiotic therapy due to lack of clinical improvement, adverse drug reactions and IV access complications. A sub-analysis of patients who received daptomycin and/or ertapenem was also performed. OPAT practice was compared with 2018 Infectious Diseases Society of America OPAT guidelines (Norris et al. Clin Infect Dis. 2019;68(1):e1-e35).

Results

A total of 108 patients were evaluated. Patient demographics, treatment and outcomes are shown in Table 1. The most common OPAT indications were bone/joint, bacteremia and skin infection. Third-generation cephalosporins, carbapenems and daptomycin were most commonly prescribed. In 34.3% and 24.2% of daptomycin and ertapenem cases, respectively, β-lactam therapy could have been utilized. Assessment of prior failed antibiotic therapy, patient allergies and pathogen-site pairing found 28.7% of patients were eligible for oral therapy upon OPAT initiation.

Conclusion

Several components of our local OPAT aligned with current guidelines. Initial OPAT patient selection may benefit from added scrutiny. Given the high volume of once daily antibiotics administered for convenience there is an internal opportunity to facilitate multi-daily infusions.

Disclosures

All authors: No reported disclosures.

1592. Safety of Oral Trimethoprim/Sulfamethoxazole Prophylaxis in Renal Transplant Recipients

Background

Trimethoprim/sulfamethoxazole (TMP/SMX) is the agent of choice for Pneumocystis jirovecii Pneumonia (PJP) prophylaxis in renal transplant (RT) recipients. All other prophylactic agents are considered second-line due to efficacy, drug intolerances, cost, administration requirements, and lack of coverage of Toxoplasma. Anecdotally, alternative agents are commonly used at our institution due to clinician hesitancy and perceived risk of adverse drug reactions (ADRs). Our objective was to assess the safety of TMP/SMX prophylaxis in RT recipients.

Methods

RT recipients transplanted at a tertiary US medical center between May 9, 2015 and November 30, 2017 were retrospectively identified. Patient charts were reviewed for antimicrobial agents used for PJP prophylaxis and ADRs due to TMP/SMX. ADRs were classified using the National Institutes of Health, Division of Microbiology and Infectious Diseases (DMID) criteria and were scored for probability of association with TMP/SMX using the Naranjo ADR probability scale.

Results

During the study period, 64 of 95 adult RT recipients (67.4%) received TMP/SMX for PJP prophylaxis. Of the patients who received TMP/SMX, 26 (40.6%) had a clinician-documented ADR attributed to TMP/SMX and 24 (37.5%) had the drug discontinued. The most frequent provider-reported ADRs due to TMP/SMX were hyperkalemia (10 patients, 15.6%), neutropenia (nine patients, 14.1%), and elevated liver function tests (LFTs) (three patients, 4.7%). However, when classified using DMID criteria, nine of the 26 ADRs were less severe than Grade 1. Two ADRs were Grade 3 (severe), including 1 case each of neutropenia and elevated LFTs. No ADRs were Grade 4 (life-threatening). All ADRs received a score ≤4 on the Naranjo ADR probability scale, indicating a possible ADR related to TMP/SMX. Often, ADRs did not resolve or other additional medication adjustments were needed following TMP/SMX discontinuation (19 of 26 patients, 73.1%). No cases of PJP occurred.

Conclusion

TMP/SMX is underutilized in RT recipients at our institution, despite being well-tolerated and efficacious. Clinician hesitancy with TMP/SMX in this population may be unfounded. Internal efforts are underway to increase the use of TMP/SMX in RT recipients.

Disclosures

All authors: No reported disclosures.

179. A Passive, Prescriber-Directed, Electronic Alert Plus Prescriber Education Decreased Antibiotic Prescribing for Ambulatory Adults With Acute, Uncomplicated Bronchitis in a Large Integrated Health System

Background

Antibiotics (ABX) are often prescribed for acute bronchitis (AB). Reducing inappropriate ambulatory ABX use is critical to combat ABX resistance and reduce ABX-related adverse events. We sought to determine the impact of a passive, prescriber-directed, electronic best practice alert (BPA) coupled with prescriber education on ABX prescribing for ambulatory adults with AB.

Methods

A retrospective, quasi-experimental study of adults with a primary diagnosis of AB discharged from any emergency department (ED), urgent care (UC), or ambulatory clinic (AC) within an integrated health system was performed. AB diagnosis codes triggered the BPA. An online continuing education course was created for prescribers. The preintervention period (PRE) was January 1, 2016–November 30, 2016 for UC and ED sites and January 1, 2016–September 28, 1017 for AC sites. The postintervention period (POST) was December 1, 2016–March 31, 2018 for UC and ED sites and September 29, 2017–March 31, 2018 for AC sites. The primary outcome was an ABX prescription targeting the upper respiratory tract. Patient- and prescriber-level data were collected. Forward stepwise multivariable (MV) logistic regression was used to determine predictors of ABX prescribing, with a P-value of < 0.05 for model entry.

Results

A total of 136,818 unique ambulatory adults had a primary diagnosis of AB. An 8.3% reduction in ABX prescribing for AB was observed (49,246 out of 79,299 patients [62.1%] pre- vs. 30,918 out of 57,519 patients [53.8%] post; P < 0.0001), corresponding to 3,652 less ABX prescriptions. ABX prescribing rates by setting are shown in Table 1 and Figure 1. In MV analysis, POST patients were less likely to receive ABX (aOR = 0.60, 95% CI = 0.58–0.62); however, patients who smoked or presented for a walk-in visit were more likely to receive ABX (aOR = 1.148, 95% CI = 1.11–1.19 and aOR = 1.45, 95% CI = 1.40–1.50, respectively).

Conclusion

A passive, prescriber-directed, electronic BPA combined with education was associated with a statistically significant reduction in ABX prescribing for ambulatory adults with AB, particularly in the ED.

Disclosures

All authors: No reported disclosures.

1424. Examining the Relationship Between Vancomycin Area Under the Concentration–Time Curve and Serum Trough Levels in Adults with Presumed or Documented Staphylococcal Infections

Background

Recent studies evaluating area under the concentration–time curve (AUC)-guided vancomycin dosing have reported reduced drug exposure and nephrotoxicity as compared with traditional trough-guided (target 15–20 mg/L) dosing for invasive infections, but studies exploring the relationship between vancomycin trough concentration and AUC remain limited.

Methods

This was a retrospective observational study performed at two hospitals within a large health system. Patients receiving AUC-guided vancomycin dosing for a presumed or confirmed invasive staphylococcal infection between December 1, 2016 and July 31, 2017 were evaluated. Two steady-state serum vancomycin levels were obtained in each patient and used to determine the 24-hour AUC/MIC ratio; the AUC/MIC target was >600 mg/L hour for endocarditis and >400 mg/L hour for all other sources. The relationship between trough and AUC was explored using the Pearson product-moment correlation coefficient. Patient demographics and dosing details were also collected.

Results

Thirty-four patients were included in the study, with two patients having vancomycin levels drawn twice (36 sets of levels). Most patients were located in an ICU (91.2%) and 85.3% of patients had bacteremia, pneumonia or endocarditis. An organism was recovered from 28 patients (82.3%) of which 21 (75%) had a vancomycin MIC of 1 mg/L and 25 were S. aureus (89.3%). The mean vancomycin trough was 16.6 ± 6.1 mg/L and the mean AUC/MIC was 588 ± 156 mg/L hour. There was a strong correlation between vancomycin trough and 24-hour AUC (R² = 0.731; P < 0.001; Figure 1). The rate of 24-hour vancomycin AUC/MIC target attainment was 91.2% (n = 31/34). Among patients with a trough >9 mg/L, 100% (n = 33) achieved AUC/MIC values >400 mg/L hour and 94% were >500 mg/L hour.

Conclusion

Targeting a vancomycin trough between 15 and 20 mg/L frequently results in an AUC/MIC in excess of the target identified for efficacy. Considering the strong correlation observed between trough and AUC alongside practical challenges associated with wide-scale implementation of AUC monitoring, a reduced target trough in conjunction with targeted application of AUC-guided dosing warrants further evaluation.

Disclosures

All authors: No reported disclosures.

1066. Adjuvant β-Lactam Therapy Combined with Vancomycin for Methicillin-Resistant Staphylococcus aureus (MRSA) Bacteremia: Does β-Lactam class Matter?

Background

Vancomycin (VAN) combined with a β-lactam (COMBO) expedites MRSA bacteremia clearance compared with VAN alone. However, the impact of COMBO on persistent MRSA bacteremia (PB) using a contemporary definition of ≥5 days is unknown. There is also no consensus on which β-lactam (BL) should be combined with VAN. We sought to assess PB rates among adults who received COMBO or VAN and the impact of BL class on PB.

Methods

This was an analysis of pooled data from two published studies of adults with MRSA bacteremia (Dilworth et al., Antimicrob Agents Chemother. 2014;58(1):102–109; Casapao et al., Pharmacotherapy. 2017;37(11):1347–1356). All patients received intravenous VAN for ≥72 hours. COMBO patients received an intravenous BL for ≥48 hours with VAN, started within 24 hours of VAN. The remaining patients comprised the VAN group. The primary outcome was PB (≥5 days). The impact of BL class on PB was assessed. Acute kidney injury (AKI, serum creatinine increase from baseline by 0.5 mg/dL or 50%) was examined as a secondary outcome. Demographics were compared between groups. Multivariable logistic regression models compared PB between COMBO and VAN.

Results

In total, 156 patients were included (VAN = 66; COMBO = 90). The groups were similar except COMBO patients were more likely to have a pulmonary bacteremia source (12.2% vs. 1.5%, P = 0.014) and a higher median (IQR) vancomycin serum level (mg/L, 17.8 (13.9, 23.6) vs. 15.7 (11.3, 20.6); P = 0.039). PB was less common in COMBO (26.7% vs. 43.9%, P = 0.027). In a multivariable model COMBO was inversely associated with PB (adjusted odds ratio [aOR], 95% confidence intervals [CI], 0.48, 0.24–0.95). AKI was more common in COMBO (18.9% vs. 7.6%, P = 0.062). PB and AKI rates by BL class are shown in the table below, with VAN listed for reference.

Conclusion

COMBO reduced the likelihood of PB but had a higher AKI rate. There were no significant differences in PB by BL class. Clinically, COMBO may reduce PB rates and prevent overuse of salvage antibiotic therapy. BL choice for COMBO warrants further investigation.

Disclosures

All authors: No reported disclosures.

1225. High Rate of Linezolid (LZD) Nonsusceptibility (LNS) Among Enteric Vancomycin-Resistant Enterococci (VRE) Recovered From Hospitalized Patients Actively Screened for VRE Rectal Colonization (VREC)

Background

Select hospitalized patients are actively screened for VREC but VRE isolates may not undergo antibiotic susceptibility testing. We sought to identify predictors of daptomycin (DAP) nonsusceptibility (DNS, MIC > 4) and LNS (MIC > 2) among enteric VRE isolates recovered from patients actively screened for VREC for which antibiotic susceptibility testing was not preformed.

Methods

This was a retrospective study of consecutive adults admitted to a surgical intensive care unit (ICU) or associated medical unit between June 1, 2017 and March 1, 2018 who had a VRE isolate from active screening. Only index isolates were included. DAP and LZD MICs were determined by Etest. Patient- and antimicrobial-level data, including ambulatory prescriptions, dating back to January 1, 2016 were collected. Multivariable logistic regression models were used to determine predictors of DNS and LNS VRE.

Results

In total, 64 patients’ VRE rectal isolates were included. Fifty-nine (92.2%) were E. faecium and 50 (78.1%) were from ICU patients. Thirty-seven patients (57.8%) were female and the mean age ± SD was 60 ± 13 years. Five (7.8%) and 20 (31.3%) patients had previous abdominal transplant and VRE infection, respectively. DAP and LZD MIC distributions are shown in the table below. Forty-one (64.1%) VRE isolates were LNS, including five LZD-resistant isolates. Only one (1.6%) isolate was DNS precluding an analysis of DNS predictors; 12 (18.8%) isolates had a DAP MIC > 2 mg/L. Common antimicrobial exposures prior to index VRE isolate included: vancomycin (62.5%), ceftriaxone (64.1%), cefepime (53.1%), metronidazole (50%), and ciprofloxacin (50%). Previous LZD (17.2%) and DAP (15.6%) exposure were less common. In a multivariable model, number of previous cefazolin doses (adjusted odds ratio (aOR) 0.74 95% confidence interval (CI) 0.55–0.95), and previous tobramycin exposure (aOR 0.15, 95% CI 0.02–0.81) were inversely associated with LNS. Previous LZD exposure was not associated with LNS.

Conclusion

LNS was common amongst VRE isolates in this cohort. Previous LZD exposure was infrequent and not associated with LNS. LZD susceptibility testing among VRE isolates recovered from patients actively screened for VREC warrants clinical consideration.

Disclosures

All authors: No reported disclosures.

318. Treatment Outcomes of Prosthetic Joint Infections: An Internal Assessment of Adherence to Best Practice Guidelines

Background

The impact of prosthetic joint infections (PJI) on patient outcomes and health systems is extensive. Patients with PJI may receive nonpreferred antibiotic therapy due to ease of administration, cost, and drug interaction profile. Our objective was to compare treatment of PJI to internal guideline-recommended therapy and assess treatment outcomes.

Methods

To reduce heterogeneity of PJI treatment within a large, integrated health system, our antimicrobial stewardship program and orthopedic surgeons created an internal best-practice guideline for treatment of PJI based on published literature. The guideline is organism and surgery specific (Figure 1). Patients who had total knee arthroplasty (TKA) or total hip arthroplasty (THA) and subsequently developed PJI from July 2016 to June 2017 were identified retrospectively. Recurrent infections were defined as recurrence of primary infections or new infections with other organisms. Rates between patients treated with guideline-concordant and guideline-discordant regimens were compared.

Results

Among 36 TKAs complicated by PJI, fewer patients who received guideline-concordant therapy experienced recurrent infection than patients who received guideline-discordant therapy (1 of 16 patients [6.25%] vs. nine of 20 patients [45%], P = 0.0219). Among 25 THAs complicated by PJI, there was a trend toward fewer recurrent infections when patients received guideline-concordant therapy (2 of 12 patients [16.7%] vs. 5 of 11 patients [45.5%], P = 0.1775). Common deviations from the guidelines included daptomycin use for methicillin-susceptible Staphylococcus spp. with implant retention due to ease of administration in outpatient settings and avoidance of rifampin due to tolerability or drug interactions.

Conclusion

Deviation from treatment guidelines for PJI following TKA and THA may increase the risk of recurrent infection. Barriers to utilizing guideline-recommended antibiotics in the outpatient setting should be addressed. Institutions should develop internal consensus on PJI treatment with prospective surveillance.

Disclosures

All authors: No reported disclosures.

Clinical and Economic Effects of a Pharmacist-Administered Antiretroviral Therapy Adherence Clinic for Patients Living with HIV

BACKGROUND

Pharmacists have demonstrated the ability to improve patient adherence to antiretroviral therapy (ART).

OBJECTIVE

To determine the clinical and economic effects of a pharmacist-administered ART adherence clinic for patients living with human immunodeficiency virus (HIV).

METHODS

This pilot study with a pretest-posttest design examined the effect of a pharmacy adherence clinic on patient HIV viral load and CD4 count over a 6-month period. Patients with documented adherence problems were referred to the clinic. The pharmacist counseled patients at baseline and met with patients 1-2 weeks, 6 weeks, 3 months, and 6 months after starting ART. A societal perspective net cost analysis of the pharmacy adherence clinic was conducted to assess the economic efficiency of the intervention.

RESULTS

Twenty-eight patients were enrolled in the study, and 16 patients reached completion. Median HIV RNA significantly decreased from 48,000 copies/mL (interquartile range [IQR] = 16,750-139,000) to undetectable (< 20 copies/mL) at 6 months for all study participants who completed the full intervention (P = 0.001). In the 3 months following the intervention, we estimated that it prevented approximately 0.13 secondary HIV infections among the sexual partners of the 16 participants who completed the intervention. The total cost of the intervention was $16,811 ($1,051 per patient), which was less than the future savings in averted HIV-related medical care expenditures ($49,702).

CONCLUSIONS

A pharmacy adherence clinic that focused on early and sustained ART adherence interventions helped patients with documented medication adherence problems achieve an undetectable HIV RNA. The intervention was highly cost saving, with a return of nearly $3 in future medical care savings per dollar spent on the intervention.

DISCLOSURES

This work was supported in part by a research grant to Dilworth, Mercier, and Borrego from the American Society of Health-System Pharmacists Foundation. Klein and Pinkerton were supported in part by grants T32-MH19985 and P30-MH52776, respectively, from the National Institute of Mental Health. No funding bodies had any role in the study design, data collection, analysis, decision to publish, or preparation of the manuscript. The findings and conclusions in this article are those of the authors and do not necessarily represent the official position of the Health Resources and Services Administration. The authors have no conflicts of interest to disclose. Study concept and design were contributed primarily by Dilworth, Mercier, and Borrego, along with the other authors. Dilworth took the lead in data collection, along with Pinkerton, Klein, Mercier, and Jakeman. Data interpretation was performed by Dilworth and Pinkerton, along with the other authors. The manuscript was written by Dilworth, Klein, and Jakeman, with assistance from the other authors, and revised by Dilworth, Jakeman, and Klein, with assistance from the other authors. The results from this study were presented in part at the 2015 United States Conference on AIDS in Washington, DC, on September 10-13, 2015.

Results of a local combination therapy antibiogram for Pseudomonas aeruginosa isolates: is double worth the trouble?

Purpose

To determine the frequency at which fluoroquinolones and aminoglycosides demonstrate in vitro activity against non-urinary, non-skin/skin structure Pseudomonas aeruginosa isolates exhibiting decreased susceptibilities to one or more β-lactam agents.

Methods

β-lactam-non-susceptible P. aeruginosa isolates recovered from blood, bone, lower respiratory tract, pleural fluid, cerebrospinal fluid, or peritoneal fluid cultures between October 2010 and October 2014 were reviewed from four community hospitals within a single health-system. Only the first isolate per patient was included for analysis. The likelihood that each isolate was susceptible to a non-β-lactam antimicrobial was then determined and summarized within a combination antibiogram.

Results

In total, 179 P. aeruginosa isolates with decreased susceptibilities to one or more β-lactam agents were assessed. Because no appreciable differences in antimicrobial susceptibility profile were observed between hospitals, the isolates were evaluated in aggregate. Susceptibility rates for β-lactam monotherapy ranged from 34% to 75%. Aminoglycosides possessed increased antibacterial activity compared to fluoroquinolones. Tobramycin was the non-β-lactam most likely to expand antimicrobial coverage against β-lactam-non-susceptible P. aeruginosa with activity against 64%, 66%, and 65% of cefepime-, piperacillin-tazobactam-, and meropenem-non-susceptible isolates, respectively (p < 0.001 for all).

Conclusions

The results of this study support the use of aminoglycosides over fluoroquinolones for achieving optimal, empiric antimicrobial combination therapy for P. aeruginosa when dual antimicrobial therapy is clinically necessary. Future efforts aimed at optimizing combination therapy for P. aeruginosa should focus on systemic interventions that limit the selection of fluoroquinolones in combination with β-lactams to expand coverage based on local susceptibility rates.

Agricultural Applications for Antimicrobials. A Danger to Human Health: An Official Position Statement of the Society of Infectious Diseases Pharmacists

The use of antibiotics in agriculture, particularly in food-producing animals, is pervasive and represents the overwhelming majority of antibiotic use worldwide. The link between antibiotic use in animals and antibiotic resistance in humans is unequivocal. Transmission can occur by ingesting undercooked meats harboring resistant bacteria, by direct contact of animals by animal handlers, and by various other means. Antibiotics used in aquaculture and antifungals used in horticulture are also an evolving threat to human health. Regulations aimed at decreasing the amount of antibiotics used in food production to limit the development of antibiotic resistance have recently been implemented. However, further action is needed to minimize antibiotic use in agriculture. This article describes the extent of this current problem and serves as the official position of the Society of Infectious Diseases Pharmacists on this urgent threat to human health.

Therapeutic Advances in HCV Genotype 1 Infection: Insights from the Society of Infectious Diseases Pharmacists

Hepatitis C virus (HCV) is the most common blood-borne infection in the United States. The high morbidity and mortality due to untreated infection have prompted updated screening recommendations that now include one-time HCV screening for all patients born between 1945 and 1965, in addition to risk factor-based screening. Current guidelines recommend treatment for all patients with chronic HCV. Treatment for HCV genotype 1 has evolved dramatically since the approval of the direct-acting antivirals. The approval of ledipasvir-sofosbuvir, ombitasvir-paritaprevir-ritonavir and dasabuvir, and simeprevir with sofosbuvir has dramatically altered the treatment landscape. High sustained virologic response (SVR) rates favor treatment, yet access to care poses a challenge for patients and providers. Current and emerging data with new therapies indicate high SVR rates in treatment-naïve and treatment-experienced patients, including patients with cirrhosis and in other special populations. Additional data suggest the addition of ribavirin can decrease treatment duration without compromising SVR rates. Resistance is an increasing area of interest in HCV, with baseline mutations identified and the potential for the development of resistance-associate variants in patients undergoing treatment. Due to the rapid evolution of HCV treatment, pharmacists should address challenges and play an integral role in agent selection, dosing, drug interaction screening, adverse effect monitoring, and the coordination of treatment. Clinical application of the latest information will reduce patient risk and improve outcomes.

Impact of an intravenous trimethoprim/sulfamethoxazole shortage on treatment outcomes among HIV-infected patients with Pneumocystis jirovecii pneumonia

BACKGROUND

Trimethoprim/sulfamethoxazole (TMP/SMX) is the recommended first-line treatment for human immunodeficiency virus (HIV)-infected patients with Pneumocystis jirovecii pneumonia (PJP).However, in June 2010, the lone manufacturer of intravenous (IV) TMP/SMX in the United States stopped production of this medication. 

OBJECTIVES

To (a) evaluate the impact of the national IV TMP/SMX shortage on PJP treatment outcomes between 2 groups of HIV-infected patients-those treated before the shortage and those after the shortage-and (b) compare the length of hospital stay (LOS) and PJP treatment used before and after the shortage.

METHODS

A retrospective, quasi-experimental study examining 2 groups of HIV-infected adult patients with PJP was performed at an academic medical center from September 1, 2008, to June 30, 2012. Patients treated when IV TMP/SMX was available, or preshortage (PRE), were compared with patients treated when IV TMP/SMX was not available, or postshortage (POST).PRE included patients treated between September 1, 2008, and May 30, 2010, and POST included patients treated between June 1, 2010, and June 30, 2012.  

RESULTS

Thirty-six patients were included in the study, 18 in each group. Treatment failure, the primary outcome, included mortality or worsening clinical status (WCS) after at least 5 days of therapy. Three patients in PRE (16.7%) and 6 patients in POST (33.3%) experienced treatment failure (P = 0.248). No patients in PRE and 3 patients in POST (16.7%) experienced WCS (P = 0.035). Three patients in each group expired.In POST, 5 of the 6 treatment failures (83.3%) occurred during the first 6 months of the shortage. Median (interquartile range) LOS was 11 days (7-17) in PRE and 14 days (5-22) in POST (P = 0.800).In PRE, 7 patients (38.9%) were initiated on oral PJP treatment compared with 13 (72.2%) in POST (P = 0.042). 

CONCLUSIONS

The national shortage of IV TMP/SMX may have led to an immediate but temporary negative impact on treatment outcomes among HIV-infected patients with PJP at an academic medical center.Pharmacist collaboration with physicians may have helped mitigate the impact of this drug shortage on patient outcomes.  

Vancomycin and piperacillin-tazobactam against methicillin-resistant Staphylococcus aureus and vancomycin-intermediate Staphylococcus aureus in an in vitro pharmacokinetic/pharmacodynamic model

PURPOSE

Synergy between β-lactams and vancomycin against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-intermediate Staphylococcus aureus (VISA) has been observed in vitro and in vivo. However, studies investigating piperacillin-tazobactam with vancomycin against MRSA and VISA are limited despite broad clinical use of these antibiotics in combination. This study evaluated vancomycin and piperacillin-tazobactam against MRSA and VISA by using an in vitro pharmacokinetic/pharmacodynamic model.

METHODS

Two clinical MRSA strains (M3425 and M494) and one VISA strain (Mu50) were tested in duplicate by using a 72-hour, 1-compartment pharmacokinetic/pharmacodynamic model with the following exposures: growth control, vancomycin only, piperacillin-tazobactam only, and vancomycin with piperacillin-tazobactam. Vancomycin 1 g every 12 hours (free trough concentration, 8.75 mg/L; Cmin, 17.5 mg/L) and piperacillin-tazobactam 13.5 g per 24 hours' continuous infusion (free steady-state concentration, 27 mg/L) were simulated. Time-kill curves were constructed, and reductions in log10 CFU/mL at all time points were compared between regimens tested.

FINDINGS

Vancomycin and piperacillin-tazobactam MICs for M494, M3425, and Mu50 were 1, 1, and 4 and 1.5, 32, and >256 mg/L, respectively. All isolates had an oxacillin MIC ≥ 4 mg/L. Against all 3 isolates, vancomycin with piperacillin-tazobactam achieved a significant reduction in inoculum at 72 hours compared with vancomycin alone (all, P ≤ 0.015). The superiority of vancomycin with piperacillin-tazobactam compared with vancomycin alone became detectable at 8 hours for M3425 (P < 0.001) and at 24 hours for M494 and Mu50 (both, P ≤ 0.008). Although vancomycin with piperacillin-tazobactam achieved enhanced antibacterial activity at 72 hours against M3425 compared with vancomycin alone, bacterial regrowth occurred. Reduced susceptibility to vancomycin at 72 hours for M3425 was confirmed by using population analysis profile/AUC analysis. At 72 hours, M3425 had a PAP/AUC ratio of 0.77 compared to 0.51 at baseline.

IMPLICATIONS

Vancomycin with piperacillin-tazobactam demonstrated enhanced antimicrobial activity against MRSA and VISA compared with vancomycin alone. These results further enhance existing data that support using vancomycin in combination with a β-lactam for invasive MRSA infections. Combination therapy with vancomycin and a β-lactam against MRSA warrants clinical consideration.

Impact of pharmacist discharge medication therapy counseling and disease state education: Pharmacist Assisting at Routine Medical Discharge (project PhARMD)

Many patients experience adverse events after discharge; numerous are medication related and preventable. The objective of this study is to evaluate the impact of pharmacist medication counseling and disease education at discharge. Pharmacist Assisting at Routine Medical Discharge is a prospective study of English- or Spanish-speaking adults discharged from internal medicine. Control patients received usual hospital discharge care; intervention patients received usual care with discharge counseling and a follow-up phone call. Evaluated outcomes included the following: 30-day hospital reutilization (combined readmissions/emergency department visits), pharmacist interventions, predictors for hospital utilization, patient satisfaction, and primary medication adherence. In all, 279 patients were enrolled: 139 in the control and 140 in the intervention group. Pharmacists made 198 interventions. The rate of hospital reutilization was 20.7% and similar between the intervention and control groups. Patients receiving the pharmacist intervention demonstrated improved primary medication adherence and increased patient satisfaction. Pharmacist-provided discharge counseling resulted in medication interventions, improved patient satisfaction, and increased medication adherence.

Development and evaluation of an instrument to measure community pharmacists' self-efficacy beliefs about communicating with Spanish-speaking patients

BACKGROUND

Hispanics are the largest growing population in the United States, and their use of prescription medications can be influenced by the education and counseling they receive from pharmacists. However, little is known about pharmacists' communication with patients who speak Spanish or factors that can influence such communication.

OBJECTIVES

The objective of the study was to develop and validate an instrument to measure pharmacists' self-efficacy in communicating with Spanish-speaking patients.

METHODS

An initial pool of 15 items developed from previous research and suggestions from communication experts and practicing pharmacists was subjected to cognitive interviewing. Nine retained items were administered to 1022 licensed pharmacists by mail survey. Summary statistics and exploratory factor analysis (EFA) were conducted. Retained factors were determined by the examination of eigenvalues and scree test results. Cronbach's alpha coefficients were calculated to assess internal consistency.

RESULTS

A total of 540 community pharmacists completed the survey. Item means ranged from 2.93±1.47 to 1.58±0.88 based on a 5-point scale (1: not at all confident to 5: extremely confident). EFA resulted in a 2-factor solution, accounting for 71% of the variance. The 2 factors consisted of health and drug information (alpha=0.92) and opening the encounter (alpha=0.75). The alpha for the overall scale was 0.88.

CONCLUSIONS

The results provide evidence to support the reliability and validity of an instrument to measure pharmacists' self-efficacy beliefs about communicating with Spanish-speaking patients in community practice. Practitioners and researchers may use this instrument to inform pharmacy education, pharmacy practice improvement, and research efforts around communicating with Spanish-speaking clients.