Estes, Lynn L.

Background: Because both daptomycin and statins may increase creatine phosphokinase (CPK) levels, the manufacturer of daptomycin suggests considering holding statins during daptomycin therapy. Published evidence suggests potential detrimental effects of withdrawing statin therapy. Objectives: The objectives of this study were to determine the impact of concurrent statin therapy on peak CPK values, incidence of CPK elevation in patients receiving daptomycin therapy, and clinical factors associated with increased risk of developing CPK elevation. Methods: This was a single-center, retrospective cohort study of patients ≥18 years of age who received daptomycin for ≥72 hours and had ≥1 follow-up CPK during a 5-year period. A Kaplan-Meier curve was used to evaluate time to CPK elevation. Cox regression analyses were used to compare the risk of developing elevated CPK between 3 study groups: those receiving daptomycin alone, daptomycin with concurrent statin therapy, and statin therapy held while on daptomycin. Results: 498 patients were included in the study—384 received daptomycin alone, 63 received daptomycin concurrent with statin, and 51 with statin held during daptomycin therapy. Cumulative incidence of CPK elevation was 5.1% and 12% at 7 and 14 days. Those on daptomycin and statin concurrent therapy demonstrated an approximately 2-fold risk of CPK elevation compared with those having their statin therapy held, but the overall group effect was not statistically significant ( P = .17). Conclusions: Our findings suggest that holding statin during daptomycin therapy may not be necessary, but may indicate need for increased frequency of CPK monitoring when these medications are used concurrently.

ABSTRACT QTc prolongation is a risk factor for development of torsades de pointes (TdP). Combination therapy with fluoroquinolones and azoles is used in patients with hematologic malignancies for prophylaxis and treatment of infection. Both drug classes are implicated as risk factors for QTc prolongation. The cumulative effect on and incidence of QTc prolongation for this combination have not been previously described. A retrospective chart review was performed with hospitalized inpatients from 1 September 2008 to 31 January 2010 comparing QTc interval data from electrocardiogram (ECG) assessment at baseline and after the initiation of combination therapy. Ninety-four patients were eligible for inclusion. The majority, 88 patients (93.6%), received quinolone therapy with levofloxacin. Fifty-three patients (56.4%) received voriconazole; 40 (42.6%) received fluconazole. The overall mean QTc change from baseline was 6.1 (95% confidence interval [CI], 0.2 to 11.9) ms. Twenty-one (22.3%) of the studied patients had clinically significant changes in the QTc while receiving combination fluoroquinolone-azole therapy. Statistically significant risk factors for clinically significant changes in QTc were hypokalemia ( P = 0.03) and a left-ventricular ejection fraction of <55% ( P = 0.02). Low magnesium ( P = 0.11), exposure to 2 or more drugs with the potential to prolong the QTc interval ( P = 0.17), and female sex ( P = 0.21) trended toward significance. Combination therapy with fluoroquinolone and azole antifungals is associated with increased QTc from baseline in hospitalized patients with hematologic malignancies. One in five patients had a clinically significant change in the QTc, warranting close monitoring and risk factor modification to prevent the possibility of further QTc prolongation and risk of TdP.

Purpose Multiple studies have found an association between the prompt initiation of empirically-appropriate antimicrobial therapy and improved patient outcomes. Such empiric-antimicrobial therapy is often broad; however, once the patient's infectious syndrome, microbiology, and susceptibilities are more defined, it is important to refine antimicrobial therapy. Despite the potential benefits of an “antimicrobial de-escalation” approach, it may be difficult to enforce in clinical practice. Mayo Clinic's Computer-Based Antimicrobial Monitoring System (CBAM) is a medical-informatics tool that was used to assist in this endeavor. This study evaluates the hypothesis that CBAM can enhance the de-escalation of vancomycin and broad-spectrum combination antimicrobial therapy. Methods Hospitalized patients at the Mayo Clinic were screened from January through June 2006 using rule-based algorithms incorporated by CBAM. Interventions were performed by physicians and pharmacists as pertinent. These patients were compared with a historical group of patients obtained by CBAM reporting capabilities. De-escalation rates and mean duration of antimicrobial therapy were compared between groups. Results Vancomycin de-escalation rates significantly improved from 33% to 68% with intervention ( P = 0.001). In addition, the average duration of therapy was decreased from 10.4 ± 7.3 days to 7.7 ± 2.4 days among patients who underwent vancomycin de-escalation per recommendation ( P = 0.014). Conclusions Utilizing the Mayo Clinic's CBAM system to identify potential patients for de-escalation is a unique approach and was successful at improving adherence to vancomycin de-escalation.