Dalbavancin Sequential Therapy for Gram-Positive Bloodstream Infection: A Multicenter Observational Study.

INTRODUCTION: Long-acting lipoglycopeptides such as dalbavancin may have utility in patients with Gram-positive bloodstream infections (BSI), particularly in those with barriers to discharge or who require prolonged parenteral antibiotic courses. A retrospective cohort study was performed to provide further multicenter real-world evidence on dalbavancin use as a sequential therapy for Gram-positive BSI. METHODS: One hundred fifteen patients received dalbavancin with Gram-positive BSI, defined as any positive blood culture or diagnosed with infective endocarditis, from 13 centers geographically spread across the United States between July 2015 and July 2021. RESULTS: Patients had a mean (SD) age of 48.5 (17.5) years, the majority were male (54%), with many who injected drugs (40%). The most common infection sources (non-exclusive) were primary BSI (89%), skin and soft tissue infection (SSTI) (25%), infective endocarditis (19%), and bone and joint infection (17%). Staphylococcus aureus accounted for 72% of index cultures, coagulase-negative Staphylococcus accounted for 18%, and Streptococcus species in 16%. Dalbavancin started a median (Q1-Q3) of 10 (6-19) days after index culture collection. The most common regimen administered was dalbavancin 1500 mg as one dose for 50% of cases. The primary outcome of composite clinical failure occurred at 12.2%, with 90-day mortality at 7.0% and 90-day BSI recurrence at 3.5%. CONCLUSIONS: Dalbavancin may serve as a useful tool in facilitating hospital discharge in patients with Gram-positive BSI. Randomized controlled trials are anticipated to validate dalbavancin as a surrogate to current treatment standards.

Losartan in hospitalized patients with COVID-19 in North America: An individual participant data meta-analysis.

BACKGROUND: Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers (ARBs) have been hypothesized to benefit patients with COVID-19 via the inhibition of viral entry and other mechanisms. We conducted an individual participant data (IPD) meta-analysis assessing the effect of starting the ARB losartan in recently hospitalized COVID-19 patients. METHODS: We searched ClinicalTrials.gov in January 2021 for U.S./Canada-based trials where an angiotensin-converting enzyme inhibitors/ARB was a treatment arm, targeted outcomes could be extrapolated, and data sharing was allowed. Our primary outcome was a 7-point COVID-19 ordinal score measured 13 to 16 days post-enrollment. We analyzed data by fitting multilevel Bayesian ordinal regression models and standardizing the resulting predictions. RESULTS: 325 participants (156 losartan vs 169 control) from 4 studies contributed IPD. Three were randomized trials; one used non-randomized concurrent and historical controls. Baseline covariates were reasonably balanced for the randomized trials. All studies evaluated losartan. We found equivocal evidence of a difference in ordinal scores 13-16 days post-enrollment (model-standardized odds ratio [OR] 1.10, 95% credible interval [CrI] 0.76-1.71; adjusted OR 1.15, 95% CrI 0.15-3.59) and no compelling evidence of treatment effect heterogeneity among prespecified subgroups. Losartan had worse effects for those taking corticosteroids at baseline after adjusting for covariates (ratio of adjusted ORs 0.29, 95% CrI 0.08-0.99). Hypotension serious adverse event rates were numerically higher with losartan. CONCLUSIONS: In this IPD meta-analysis of hospitalized COVID-19 patients, we found no convincing evidence for the benefit of losartan versus control treatment, but a higher rate of hypotension adverse events with losartan.

Omadacycline in treating community-based infections: a review and expert perspective.

INTRODUCTION: Omadacycline is approved for the treatment of community-acquired bacterial pneumonia (CABP) and acute bacterial skin and soft tissue infection (ABSSSI). The integration of newer agents into clinical use involves understanding the nuances of clinical decision-making. This review will provide an in-depth focus on omadacycline in clinical practice. AREAS COVERED: Literature review of omadacycline utilizing PubMed was performed to provide a comprehensive evaluation of omadacycline pharmacology, microbiology, registrational Phase 3 clinical trials, and post-marketing clinical studies. In addition, the immunomodulatory and other attributes of tetracycline class of antibiotics, of which omadacycline is a member, are reviewed, introducing the concept of antibiotic selection with attention to the bacterial pathogen and human host relationship. EXPERT OPINION: Omadacycline builds upon the favorable attributes of tetracycline antibiotics and provides very reliable empiric coverage for both Staphylococcus aureus and Streptococcus spp. Clinicians require a more robust understanding of antibiotics, including omadacycline, in order to optimize patient outcomes, streamline care, and reduce medical costs.

Abrogation of neutrophil inflammatory pathways and potential reduction of neutrophil-related factors in COVID-19 by intravenous immunoglobulin.

Pathogenesis of lung injury in COVID-19 is not completely understood, leaving gaps in understanding how current treatments modulate the course of COVID-19. Neutrophil numbers and activation state in circulation have been found to correlate with COVID-19 severity, and neutrophil extracellular traps (NETs) have been found in the lung parenchyma of patients with acute respiratory distress syndrome (ARDS) in COVID-19. Targeting the pro-inflammatory functions of neutrophils may diminish lung injury in COVID-19 and ARDS. Neutrophils were isolated from peripheral blood of healthy donors, treated ex vivo with dexamethasone, tocilizumab and intravenous immunoglobulin (IVIG) and NET formation, oxidative burst, and phagocytosis were assessed. Plasma from critically ill COVID-19 patients before and after clinical treatment with IVIG and from healthy donors was assessed for neutrophil activation-related proteins. While dexamethasone and tocilizumab did not affect PMA- and nigericin-induced NET production ex vivo, IVIG induced a dose-dependent abrogation of NET production in both activation models. IVIG also reduced PMA-elicited reactive oxygen species production, but did not alter phagocytosis. COVID-19 patients were found to have elevated levels of cell-free DNA, neutrophil elastase and IL-8 as compared to healthy controls. Levels of both cell-free DNA and neutrophil elastase were lower 5 days after 4 days of daily treatment with IVIG. The lack of impact of dexamethasone or tocilizumab on these neutrophil functions suggests that these therapeutic agents may not act through suppression of neutrophil functions, indicating that the door might still be open for the addition of a neutrophil modulator to the COVID-19 therapeutic repertoire.

Potent Activity of Ertapenem Plus Cefazolin Within Staphylococcal Biofilms: A Contributing Factor in the Treatment of Methicillin-Susceptible Staphylococcus aureus Endocarditis.

Background: Besides antistaphylococcal beta-lactams and source control, there are limited validated antimicrobial salvage options in patients with prolonged methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia, including infective endocarditis (IE). Methods: MSSA IE cases treated with ertapenem (ETP) plus cefazolin (CZ) were compared with matched IE cases treated with standard beta-lactam monotherapy. The bactericidal activity of ETP plus CZ was also compared with nafcillin (NAF), CZ, and ETP alone using an in vitro MSSA biofilm model. Results: The median duration of bacteremia experienced by patients (n = 12) while on CZ or NAF was 4 days (range 1-16 days) compared with 1 day (range 1-3 days) for patients (n = 5) treated with ETP + CZ (P = .01, Mann-Whitney U test). Cefazolin and NAF alone or in combination did not achieve biofilm eradication at clinically relevant concentrations. However, the addition of ETP to CZ led to bactericidal eradication within biofilms at standard dosing. Conclusions: Ertapenem reduces CZ concentrations required to eradicate MSSA biofilms to those achievable in vivo by standard dosing, translating into shorter bacteremia duration in patients with MSSA endocarditis. Larger studies are needed to investigate ETP plus CZ therapy in the treatment of biofilm-related MSSA infections such as endocarditis.

Case Series of Successful Intravenous Immunoglobulin (IVIG) Treatment in 4 Pregnant Patients with Severe COVID-19-Induced Hypoxia.

BACKGROUND Despite unprecedented speed in the execution of the COVID-19 vaccine and therapeutic clinical trials, pregnant patients have been largely excluded from initial studies. In addition, pregnant patients who are unvaccinated against SARS-CoV-2 have greater morbidity risk with severe COVID-19 disease as compared to patients of similar age and comorbidity status. Intravenous immunoglobulin (IVIG) has been deemed safe in pregnancy in other diseases. Prior data demonstrate the possible benefit of utilizing IVIG for the treatment in hospitalized patients with severe respiratory symptoms associated with COVID-19 active infections when administered within 14 days of COVID symptom onset. CASE REPORT We administered IVIG (Privigen®, CSL Behring) 0.5 g/kg daily for 3 consecutive days to 4 pregnant patients (ages 24-34 years of age) who were hospitalized with moderate-to-severe COVID-19 and not vaccinated against SARS-CoV-2. All patients received concomitant glucocorticoid therapy. Gestational ages were 26, 17, 35, and 35 weeks. All patients were discharged home breathing room air after a mean hospital stay of 15 days. Two patients had uncomplicated cesarean section at 35 weeks during the hospitalization. The pre-term pregnancies at 17 and 26 weeks were intact at hospital discharge and resulted in normal vaginal deliveries at term. All 4 patients consented to participate in this case series report. CONCLUSIONS IVIG may be a safe treatment consideration in pregnant women with severe COVID-19 to avoid pregnancy complications. Its use warrants further study in pregnancy acute respiratory distress syndrome (ARDS) due to SARS-CoV-2, influenza, and other respiratory viruses to which pregnant patients are vulnerable.

Vancomycin or Daptomycin for Outpatient Parenteral Antibiotic Therapy: Does It Make a Difference in Patient Satisfaction?

A 5-question telephone survey was administered to compare satisfaction between patients receiving vancomycin vs daptomycin outpatient parenteral antimicrobial therapy (OPAT). Twenty-seven patients completed the survey (40%). Vancomycin had higher daily interference score than daptomycin (P = .03). All patients receiving daptomycin reported a satisfaction score ≥8/10, as compared to 67% of patients who received vancomycin (P < .03). OPAT antibiotics with less cumbersome administration regimens may translate into higher patient satisfaction and quicker return to life normalcy.

Current Paradigms of Combination Therapy in Methicillin-Resistant Staphylococcus aureus (MRSA) Bacteremia: Does it Work, Which Combination, and For Which Patients?

The last several years have seen an emergence of literature documenting the utility of combination antimicrobial therapy, particularly in the salvage of refractory methicillin-resistant Staphylococcus aureus (MRSA) bacteremia. Recent clinical data are shaping conundrums of which regimens may be more beneficial, which can be potentially harmful, and which subset of patients stand to benefit from more aggressive treatment regimens than called for by current standards. In addition, the incorporation of combination therapy for MRSA bacteremia should be accompanied by the reminder that antimicrobial therapy does not need to be uniform for the entire duration, with an early intensive phase in high inoculum infections (eg, with combination therapy), followed by a consolidation phase (ie, monotherapy). This review and perspective consolidates the recent data on this subject and directs future goals in filling the knowledge gaps to methodically move forward towards improving patient outcomes.

Randomized Prospective Open Label Study Shows No Impact on Clinical Outcome of Adding Losartan to Hospitalized COVID-19 Patients with Mild Hypoxemia.

INTRODUCTION: Despite considerable scientific debate, there have been no prospective clinical studies on the effects of angiotensin II receptor blockers (ARBs) on the course of COVID-19 infection. Losartan is the ARB that was chosen to be tested in this study. METHODS: Patients with COVID-19 and mild hypoxia (receipt of ≤ 3 L/min O2 by nasal cannula) admitted to three hospitals were randomized in a 1:1 ratio within 72 h of SARS-CoV-2 nucleic acid testing confirmation to prospectively receive standard of care (SOC) alone or SOC plus losartan 12.5 mg orally every 12 h for 10 days or until hospital discharge, with the option to titrate upward dependent on blood pressure tolerability. Primary composite endpoint was receipt of mechanical ventilation or death before receiving ventilation. Subjects were followed until discharge to home or until an endpoint was met in the hospital. RESULTS: Sixteen subjects received an ARB plus SOC and 15 subjects received SOC alone. The median age was 53 years for both groups. Median time from hospital admission to study enrollment was 2 days (range 1-6) for the ARB group and 2 days (range 1-4) for the SOC group. Mean Charlson comorbidity index was 2 for both groups. One subject in each group achieved the composite endpoint. CONCLUSION: This small prospective randomized open-label study showed no clinically significant impacts of ARB therapy in mildly hypoxemic patients hospitalized with COVID-19 early in the pandemic. A larger prospective randomized placebo-controlled trial would be needed to confirm these findings or capture less pronounced effects and probably should focus on outpatients earlier in disease course. TRIAL REGISTRATION: clinicaltrials.gov; March 27, 2020; NCT04340557.

Intravenous Immunoglobulin Plus Methylprednisolone Mitigate Respiratory Morbidity in Coronavirus Disease 2019.

Dysregulated neutrophil and platelet interactions mediate immunothrombosis and cause lung injury in coronavirus disease 2019. IV immunoglobulin modulates neutrophil activation through FcγRIII binding. We hypothesized that early therapy with IV immunoglobulin would abrogate immunothrombosis and improve oxygenation and reduce progression to mechanical ventilation in coronavirus disease 2019 pneumonia. DESIGN: Prospective randomized open label. SETTING: Inpatient hospital. PATIENTS AND INTERVENTION: Hypoxic subjects with coronavirus disease 2019 pneumonia were randomized 1:1 to receive standard of care plus IV immunoglobulin 0.5 g/kg/d with methylprednisolone 40 mg 30 minutes before infusion for 3 days versus standard of care alone. MAIN RESULTS: Sixteen subjects received IV immunoglobulin and 17 standard of care. Median ages were 51 and 58 years for standard of care and IV immunoglobulin, respectively. Acute Physiology and Chronic Health Evaluation II and Charlson comorbidity scores were similar for IV immunoglobulin and standard of care. Seven standard of care versus two IV immunoglobulin subjects required mechanical ventilation (p = 0.12, Fisher exact test). Among subjects with A-a gradient of greater than 200 mm Hg at enrollment, the IV immunoglobulin group showed: 1) a lower rate of progression to requiring mechanical ventilation (2/14 vs 7/12, p = 0.038 Fisher exact test), 2) shorter median hospital length of stay (11 vs 19 d, p = 0.01 Mann Whitney U test), 3) shorter median ICU stay (2.5 vs 12.5 d, p = 0.006 Mann Whitey U test), and 4) greater improvement in Pao2/Fio2 at 7 days (median [range] change from time of enrollment +131 [+35 to +330] vs +44·5 [-115 to +157], p = 0.01, Mann Whitney U test) than standard of care. Pao2/Fio2 improvement at day 7 was significantly less for the standard of care patients who received glucocorticoid therapy than those in the IV immunoglobulin arm (p = 0.0057, Mann Whiney U test). CONCLUSIONS: This pilot study showed that IV immunoglobulin significantly improved hypoxia and reduced hospital length of stay and progression to mechanical ventilation in coronavirus disease 2019 patients with A-a gradient greater than 200 mm Hg. A phase 3 multicenter randomized double-blinded clinical trial is under way to validate these findings.

Host Cathelicidin Exacerbates Group B Streptococcus Urinary Tract Infection.

Group B Streptococcus (GBS) causes frequent urinary tract infection (UTI) in susceptible populations, including individuals with type 2 diabetes and pregnant women; however, specific host factors responsible for increased GBS susceptibility in these populations are not well characterized. Here, we investigate cathelicidin, a cationic antimicrobial peptide, known to be critical for defense during UTI with uropathogenic Escherichia coli (UPEC). We observed a loss of antimicrobial activity of human and mouse cathelicidins against GBS and UPEC in synthetic urine and no evidence for increased cathelicidin resistance in GBS urinary isolates. Furthermore, we found that GBS degrades cathelicidin in a protease-dependent manner. Surprisingly, in a UTI model, cathelicidin-deficient (Camp-/-) mice showed decreased GBS burdens and mast cell recruitment in the bladder compared to levels in wild-type (WT) mice. Pharmacologic inhibition of mast cells reduced GBS burdens and histamine release in WT but not Camp-/- mice. Streptozotocin-induced diabetic mice had increased bladder cathelicidin production and mast cell recruitment at 24 h postinfection with GBS compared to levels in nondiabetic controls. We propose that cathelicidin is an important immune regulator but ineffective antimicrobial peptide against GBS in urine. Combined, our findings may in part explain the increased frequency of GBS UTI in diabetic and pregnant individuals.IMPORTANCE Certain populations such as diabetic individuals are at increased risk for developing urinary tract infections (UTI), although the underlying reasons for this susceptibility are not fully known. Additionally, diabetics are more likely to become infected with certain types of bacteria, such as group B Streptococcus (GBS). In this study, we find that an antimicrobial peptide called cathelicidin, which is thought to protect the bladder from infection, is ineffective in controlling GBS and alters the type of immune cells that migrate to the bladder during infection. Using a mouse model of diabetes, we observe that diabetic mice are more susceptible to GBS infection even though they also have more infiltrating immune cells and increased production of cathelicidin. Taken together, our findings identify this antimicrobial peptide as a potential contributor to increased susceptibility of diabetic individuals to GBS UTI.

Multicenter Cohort of Patients With Methicillin-Resistant Staphylococcus aureus Bacteremia Receiving Daptomycin Plus Ceftaroline Compared With Other MRSA Treatments.

BACKGROUND: Daptomycin and ceftaroline (DAP-CPT) have been used for persistent methicillin-resistant Staphylococcus aureus bacteremia (MRSAB), but have rarely been compared with other therapies. This study provides an exploratory analysis of patients placed on DAP-CPT vs standard of care (SOC) for MRSAB. METHODS: This is a retrospective, matched cohort study MRSAB patients at 4 hospitals in the United States. Patients receiving DAP-CPT for ≥72 hours at any point in therapy were matched 2:1 when possible, 1:1 otherwise, to SOC, first by infection source, then age and renal function. SOC was empiric treatment with vancomycin or daptomycin and any subsequent combination antibiotic(s), except for DAP-CPT. RESULTS: Fifty-eight patients received DAP-CPT with 113 matched SOC. Ninety-six percent of SOC received vancomycin, and 56% (63/113) escalated therapy at least once in the treatment course. Twenty-four patients received DAP-CPT within 72 hours of index culture; 2 (8.3%) died within 30 days vs 14.2% (16/113) with SOC (P > .05). Subgroup analysis identified numerically lower mortality in DAP-CPT patients with a Charlson comorbidity index ≥3, endovascular source, and receipt of DAP-CPT within 72 hours of index culture. The median MRSAB duration was 9.3 vs 4.8 days for DAP-CPT and SOC, respectively. DAP-CPT was initiated on day 6 on average; after receipt of DAP-CPT, MRSAB duration was 3.3 days. CONCLUSIONS: DAP-CPT treatment is often delayed in MRSAB. Combination therapy may be more beneficial if initiated earlier, particularly in patients at higher risk for mortality. Blinded, randomized, prospective studies are needed to eliminate selection bias inherent in retrospective analyses when examining DAP-CPT vs SOC.

Cefazolin and Ertapenem Salvage Therapy Rapidly Clears Persistent Methicillin-Susceptible Staphylococcus aureus Bacteremia.

Cefazolin and ertapenem combination therapy was used successfully to salvage 11 cases (6 endocarditis) of persistent methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia, including immediate clearance (≤24 hours) in 8 cases. While in vitro synergy was modest, cefazolin plus ertapenem exhibited synergistic action in a rat model of MSSA endocarditis. The combination of cefazolin and ertapenem provides potent in vivo activity against MSSA beyond what is predicted in vitro and warrants further clinical study in the treatment of refractory MSSA bacteremia and endocarditis.

Clinical Data on Daptomycin plus Ceftaroline versus Standard of Care Monotherapy in the Treatment of Methicillin-Resistant Staphylococcus aureus Bacteremia.

Vancomycin (VAN) and daptomycin (DAP) are approved as a monotherapy for methicillin-resistant Staphylococcus aureus (MRSA) bacteremia. A regimen of daptomycin plus ceftaroline (DAP+CPT) has shown promise in published case series of MRSA salvage therapy, but no comparative data exist to compare up-front DAP+CPT head-to-head therapy versus standard monotherapy as an initial treatment. In a pilot study, we evaluated 40 adult patients who were randomized to receive 6 to 8 mg/kg of body weight per day of DAP and 600 mg intravenous (i.v.) CPT every 8 h (q8h) (n = 17) or standard monotherapy (n = 23) with vancomycin (VAN; dosed to achieve serum trough concentrations of 15 to 20 mg/liter; n = 21) or 6 to 8 mg/kg/day DAP (n = 2). Serum drawn on the first day of bacteremia was sent to a reference laboratory post hoc for measurement of interleukin-10 (IL-10) concentrations and correlation to in-hospital mortality. Sources of bacteremia, median Pitt bacteremia scores, Charlson comorbidity indices, and median IL-10 serum concentrations were similar in both groups. Although the study was initially designed to examine bacteremia duration, we observed an unanticipated in-hospital mortality difference of 0% (0/17) for combination therapy and 26% (6/23) for monotherapy (P = 0.029), causing us to halt the study. Among patients with an IL-10 concentration of >5 pg/ml, 0% (0/14) died in the DAP+CPT group versus 26% (5/19) in the monotherapy group (P = 0.057). Here, we share the full results of this preliminary (but aborted) assessment of early DAP+CPT therapy versus standard monotherapy in MRSA bacteremia, hoping to encourage a more definitive clinical trial of its potential benefits against this leading cause of infection-associated mortality. (The clinical study discussed in this paper has been registered at ClinicalTrials.gov under identifier NCT02660346.).

Is a Reported Penicillin Allergy Sufficient Grounds to Forgo the Multidimensional Antimicrobial Benefits of ß-Lactam Antibiotics?

The majority of patients with reported penicillin allergy are not allergic when tested or challenged. Penicillin allergy testing has been shown to significantly reduce annual healthcare expenditures. Data have emerged showing ß-lactams have multidimensional antibacterial effects in vivo, far beyond what is appreciated in standard bacteriological susceptibility testing media. These include enhancing bacterial killing by the innate immune system. Supporting the clinical relevance of these secondary underappreciated effects are recent clinical and pharmacoeconomic analyses that show worse outcomes in patients with reported penicillin allergies who receive non-ß-lactam antibiotics when compared to their non-penicillin-allergic counterparts. This is particularly relevant in the treatment of Staphylococcus aureus bacteremia. This article reviews the tremendous advantages offered by ß-lactam therapy and makes a strong case that the debunking of false penicillin allergies through a detailed allergy history and penicillin allergy testing should be a vital component of antimicrobial stewardship practices.

Efficacy and safety of daptomycin in patients with renal impairment: a multicenter retrospective analysis.

STUDY OBJECTIVE: Daptomycin is a therapeutic option for patients with underlying renal insufficiency who are vulnerable to nephrotoxicity from vancomycin. We evaluated the efficacy and safety of daptomycin in patients with renal impairment. DESIGN: Multicenter, retrospective, observational, case series analysis. SETTING: Two academic medical centers. PATIENTS: One hundred and sixty adults with creatinine clearance (Clcr ) of 50 ml/minute or less who received daptomycin for at least 72 hours for complicated Gram-positive infections from 2008-2011. MEASUREMENTS AND MAIN METHODS: Clinical and microbiologic outcomes were assessed at the end of daptomycin therapy. Safety evaluations were documented for all patients, and when available, creatine phosphokinase (CPK) levels were recorded. Thirty-eight (23.8%) patients were on hemodialysis, and 122 (76.3%) had a decreased baseline renal clearance not requiring hemodialysis with a median interquartile range (IQR) Clcr of 32.4 ml/minute (24.2-40.4 ml/min). The median (IQR) daptomycin dose was 6.0 mg/kg (5.8-7.8 mg/kg) administered every 24 hours in 68 patients (42.5%) and every 48 hours in 92 patients (57.5%). Daptomycin success, including cure or improvement, (Cure: signs and symptoms resolved and no additional antibiotic therapy required, or infection cleared with negative cultures reported at the end of daptomycin therapy; Improvement: partial resolution of signs and symptoms and additional antibiotic therapy necessary at the end of daptomycin therapy) was achieved in 128 of 160 (80.0%) patients at the end of therapy. Methicillin-resistant Staphylococcus aureus (MRSA) was the most common pathogen (45%) isolated. The most frequent reason for using daptomycin was due to vancomycin-associated nephrotoxicity (20%). Daptomycin therapy was discontinued in six patients (3.8%) because of elevated CPK (median time to onset, 11.5 days). Loss of daptomycin susceptibility occurred in two patients with complex endovascular infections who were on hemodialysis. CONCLUSIONS: Daptomycin demonstrated clinical and microbiologic success rates comparable with prior studies. Discontinuation of therapy because of elevated CPK levels may have been avoided in some patients with adjustment to every 48-hour dosing for Clcr less than 30 ml/minute. The relatively early time to onset suggests the need for CPK monitoring more frequently than once/week in renally impaired patients receiving daptomycin. The treatment of bacteremia in patients with renal insufficiency warrants further study.