751. Study on Daptomycin Prescription Suitability as a First Step Towards an Antimicrobial Stewardship Program

Background Daptomycin use has increased since its approval and has often extended to indications not included in the summary of product characteristics with highly variable dosing. Our objective was to assess daptomycin real use in an institution with Pharmacy and ID consultation available and to explore the need for establish specific Daptomycin stewardship. Methods Observational, retrospective study including all patients treated with daptomycin during 2017 in a tertiary hospital. Clinical variables were collected in a pre-established protocol including demographics, comorbidities, infection type, microbiological results, adverse events (AE), outcomes, and treatment adequacy (selection, dosage, microbiological adjustment and duration). Daptomycin prescription is not restricted at our institution. The dosages were considered adequate according to clinical guidelines. Results Overall 176 patients (62% men, median age: 70years) started treatment with daptomycin, 58% of them on empirical bases. Main uses were: skin and soft-tissue infections (37.5%), fever without obvious source (17.6%) and osteoarticular infection (12.5%). Sixty-three patients (35.8%) had concomitant bacteremia. An etiologic diagnosis was reached in 89.2% patients and S.aureuswas the most frequently isolated microorganism (n = 58, and 10 MRSA), followed by CoNS (n = 35). Overall, 77.7% of patients evolved satisfactorily. Five patients discontinued treatment due to AE (urticaria, cholestasis, increased CPK and rhabdomyolysis). Infection-related mortality was 7.4%. Daptomycin was correctly selected in 94.3% patients, length of therapy was adequate in 87.4%. However, only 47.1% of patients received adequate dosage (underdosing in 27.8%) and in 9.8% of patients, the treatment was not adjusted according to microbiological results. The prevalence of daptomycin use was 3.7 patients/1,000 admissions. Conclusion Daptomycin is often prescribed empirically, using nonadequate dosages and duration of therapy needs also an improvement. The follow-up of patients treated with daptomycin should be considered a priority intervention within an Antimicrobial Stewardship Program. Disclosures All authors: No reported disclosures.