Adding losartan to lisinopril therapy in patients,vith hypertension: Assessment by 24-hour ambulatory blood pressure monitoring

The aim of this study was to assess the effects of adding losartan to Lisinopril on 24-hour blood pressure (BP) values and on the renin-angiotensin system (RAS) in patients with hypertension whose condition was not controlled by lisinopril monotherapy. We studied 52 patients with essential hypertension (27 men, 25 women; mean age, 56 +/- 6 years) with sitting diastolic blood pressure (DBP) >90 mm Hg after 4 weeks of monotherapy with lisinopril 10 mg once daily. The patients were randomly allocated to receive either losartan 50 mg once daily in addition to lisinopril 10 mg once deny or a double dose of Lisinopril (20 mg once daily) for 4 weeks, according to a double-masked, crossover design. At the end of each treatment period, casual BP and heart rate mere measured, noninvasive 24-hour ambulatory blood pressure monitoring was performed, and a blood sample was obtained to measure plasma renin activity (PRA) and angiotensin (Ang)I and II levels. The combined administration of losartan 50 mg and lisinopril 10 mg produced a greater reduction in both ambulatory and casual systolic BP and DBP values compared with lisinopril 20 mg. The additive BP-lowering effect of the combination therapy occurred during both the 24-hour period and the single daytime and nighttime subperiods, without interfering with the normal circadian BP pattern. Furthermore, the losartanlisinopril combination increased PRA and Ang I more than Lisinopril 20 mg and decreased the losartan-induced peak value of Ang II. Results of this study suggest that the addition of losartan to lisinopril therapy was more effective in decreasing BP and increasing PEA and Ang I than doubling the lisinopril dose; therefore, a more complete RAS blockade might improve BP control in patients with hypertension.