Michael Guo, Mahyar Etminan* and Bruce Carleton Pages 74 - 78 ( 5 )
Background: Lorcaserin and phentermine-topiramate are two drugs marketed for obesity that have shown moderate efficacy after one year of use. However, concerns over risks of serious cardiovascular harms including valvulopathy have been brought up for both drugs, prompting an epidemiologic investigation to quantify this adverse outcome using real-world clinical data.
Objective: To compare rates of valvulopathy between the weight-loss drugs lorcaserin and phentermine-topiramate.
Methods: A retrospective cohort study using the PharMetrics database from the United States was conducted. From approximately 9 million subjects captured in the database from 2006 to 2016, we identified all patients who had received at least one prescription for lorcaserin or phentermine-topiramate. Users of either drug were followed to the first mutually exclusive diagnosis of non-congenital valvulopathy defined as having received an international classification for diseases, ninth revision clinical modification [ICD-9- CM] code for valvulopathy, or to the end of the study period. A Cox Proportional Hazards model was then constructed to compute adjusted hazard ratios (HRs) to compare the rates of valvulopathy between users of the two drugs.
Results: We identified 1,981 lorcaserin users and 1,806 phentermine-topiramate users. Rates of valvulopathy for lorcaserin and phentermine-topiramate cohorts were 26 and 24 per 1000-person-years, respectively. The crude and adjusted hazard ratios (HRs) comparing the two cohorts with respect to valvulopathy were 1.28 (95% CI: 0.73,2.26) and 1.16 (95% CI: 0.65-2.05), respectively.
Conclusion: Our analysis suggests comparable rates of valvulopathy between lorcaserin and phentermine-topiramate users. Clinicians are advised to consider the risk of valvular disease when medically managing obesity.
Valvulopathy, lorcaserin, phentermine, topiramate, cohort study, non-congenital.
Faculty of Medicine, University of British Columbia, Vancouver, BC, Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC, Division of Translational Therapeutics, Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, BC