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
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.