BackgroundA dronedarone utilization study using US MarketScan and InVision Data Mart databases was conducted to estimate the prevalence of the following: (1) dronedarone use in contraindicated patients with worsening heart failure (HF) or hospitalization for HF within 1 month before dronedarone prescription; (2) concomitant prescribing of contraindicated drugs; and (3) recommended creatinine testing after dronedarone initiation among dronedarone users. MethodsIn this retrospective cohort study, data in the MarketScan database between July 20, 2009, and December 31, 2011, and in the InVision Data Mart database between July 20, 2009, and March 31, 2012, were analyzed. The study population included patients who received ≥1 dronedarone prescription during the study period. The following variables were reported: worsening of or hospitalization for HF, concomitant prescribing of potent cytochrome P450 CYP 3A4 inhibitors or QT-prolonging drugs, and creatinine testing. ResultsThere were 31,408 and 7025 dronedarone users identified in the MarketScan and InVision Data Mart databases, respectively. Approximately 86% to 90% of patients had a diagnosis of atrial fibrillation in each database. In the MarketScan database, 40% were women and 54% were aged ≥65 years. In the InVision Data Mart database, 31% were women and 32% were aged ≥65 years. The corresponding prevalence of worsening or hospitalization for HF was 6.4% (95% CI, 6.2–6.7) and 4.7% (95% CI, 4.2–5.2) in each database, respectively. The corresponding estimates of concomitant prescribing of potent cytochrome P450 CYP 3A4 inhibitors and QT-prolonging drugs within 30 days before initiation or refilling of dronedarone were 2.0% (95% CI, 1.8–2.1) and 10.0% (95% CI, 9.7–10.4), respectively, in the MarketScan database, and 2.3% (95% CI, 2.0–2.7) and 11.2% (95% CI, 10.5–12.0) in the InVision Data Mart database. More than 50% of patients in each database had serum creatinine tests conducted after dronedarone initiation. ConclusionsThe results of the present analysis based on a long-term follow-up (nearly 3 years) were consistent with the previous findings that dronedarone has mostly been used appropriately in compliance with US prescribing in the target populations.