P-420: Effect of the fixed combination of irbesartan 300 mg/hydrochlorothiazide 25 mg on the circadian blood pressure profile in essential hypertension

• Published in: American journal of hypertension 2003-05, Vol.16 (S1), p.189A-189A
• Main Authors: Coca, Antonio, Calvo, Carlos, Sobrino, Javier, Sierra, Cristina, López-Paz, José E., Gómez-Angelats, Elisenda, Bragulat, Ernest, de la Sierra, Alejandro
• Format: Article
• Language: English
• Subjects: Irbesartan / Hydrochlorothiazide; Smoothness Index; Trough-to-peak ratio
• ISSN: 0895-7061; 1941-7225; 1879-1905
• DOI: 10.1016/S0895-7061(03)00592-2

Most hypertensive patients included in morbidity and mortality trials needed two or more drugs to achieve a sustained blood pressure reduction. Therefore, safe combinations using higher doses of antihypertensive drugs are frequently required to control blood pressure. The aim of the present study is to evaluate the magnitude of the effect of a once-daily fixed combination of irbesartan 300/hydrochlorothiazide 25 mg on the circadian blood pressure profile in essential hypertensive patients not controlled with full-dose single therapy or low-dose combined therapy. After a 1-week wash-out period, 57 patients (28m, 29f) aged 45-78 years showing a mean daytime-BP (from 10:00 to 20:00 hours) higher than 135/85 mmHg were treated with irbesartan 300/HCTZ 25 for 12 weeks. Twenty-four hour ambulatory blood pressure monitoring (ABPM) was performed at the end of the wash-out period and during the last week of treatment. After treatment a significant reduction in the average values of both clinic and ambulatory BP values was observed in the whole group of 57 patients (from 146.0± 11.0 to 123.3± 13.3 mmHg, p 5 mmHg of either 24h-SBP or 24h-DBP values) and the control rate 68.4% (daytime BP< 135/85 mmHg) at the end of treatment. The average lowering of ambulatory SBP and DBP at peak was 25.2± 14.5 and 14.7± 9.5, respectively, whereas the lowering at trough was 22.3± 18.3 and 12.3± 10.9 mmHg, respectively. The trough-to-peak ratio (T/P) of the group was 0.92 for SBP (0.97 in responders) and 0.84 for DBP (0.89 in responders). The smoothness index (SI) calculated as the average of all individual values was 1.66± 1.0 for SBP (1.76± 0.9 in responders) and 1.29± 0.8 for DBP (1.48± 0.6 in responders). Only 7 side effects in 6 patients were reported. No metabolic changes were observed and no patient discontinued the study. The fixed combination of irbesartan 300/HCTZ 25 administered once-daily was very effective in reducing 24-hour blood pressure and very well tolerated, preserving the circadian profile as showed by T/P ratios very close to 1 and SI > 1 for both SBP and DBP.