Evaluation of Impact of Statin Use on Development of CPK Elevation During Daptomycin Therapy

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.