The Impact on Blood Pressure Control after Switching from Perindopril to Lisinopril: A Retrospective Crossover Study

Abstract

Aim: Based on the consideration on drug expenditure, General Out Patient Clinic (GOPC) in New Territories East Cluster (NTEC) has decided to switch all the patients previously on perindopril to lisinopril by a conversion table but there is no evidence behind this recommendation. This retrospective crossover study is then conducted in order to investigate whether there is a change in blood pressure control after the switch. Method: Data used in this study is retrieved by CDARS (Clinical Data Analysis and Reporting System), CDDH (Cooperate Drug Dispensing System) and EPR (Electronic Patient Record). 2 sided paired t-test is used to investigate whether there is a significant change in blood pressure after the switch. Moreover, subgroup analysis will also be done on the 4 different dosage subgroups. ANOVA is also performed to identify any intergroup difference. Results: There are a total of 617 patients being retrieved for data analysis and 269 patients are included for data analysis. The average blood pressure before the switch is 77.72/134.61 mmHg and the average blood pressure after the switch is 77.83/134.84 mmHg and they are not statistically different (for the diastolic blood pressure, p = 0.7619 > 0.05 and for systolic blood pressure, p = 0.9143 > 0.05). The subgroup analysis results in similar findings except for the Systolic blood pressure, 20 mg lisinopril (134.02 mmHg) performs better than 8 mg perindopril (138.48 mmHg), p = 0.0426 <0.05. ANOVA do not show any intergroup difference between the 4 subgroups. Conclusion: To conclude, the conversion table proposed in this study can be used as an initial guide for switching from perindopril to lisinopril since there is no change in blood pressure after the switch. However, close monitoring should be done in order to perform adjustment in medication if the blood pressure control is not adequate.