title: Once-daily fixed-combination irbesartan 300 mg/ hydrochlorothiazide 25 mg and circadian blood pressure profile in patients with essential hypertension.
abstract: BACKGROUND
  More than 60% of patients with hypertension included in morbidity and mortality trials needed >or=2 drugs to achieve a substantial, sustained reduction in blood pressure. Tolerable combinations using higher doses of antihypertensive drugs are frequently required to control blood pressure.
  
  
  OBJECTIVE
  The goal of this study was to assess the effect of a once-daily fixed combination of irbesartan 300 mg/hydrochlorothiazide (HCTZ) 25 mg on the circadian blood pressure profile in patients with essential hypertension that was not controlled with full-dose single therapy or low-dose combined therapy.
  
  
  METHODS
  Study patients were recruited consecutively from the outpatient hypertension clinics of 3 university hospitals in Spain. After a 1-week washout period, patients with a mean daytime blood pressure >135/85 mm Hg were treated with irbesartan 300 mg/HCTZ 25 mg once daily for 12 weeks. Twenty-four-hour ambulatory blood pressure monitoring was performed at the end of the washout period and during the last week of treatment.
  
  
  RESULTS
  Fifty-seven patients with essential hypertension (28 men, 29 women) were enrolled; their mean (SD) age was 60.4 (7.2) years (range, 45-78 years). After treatment, a significant reduction in both clinic and ambulatory mean (SD) blood pressure values was observed in the whole group of 57 patients (from 146.0 [11.0] mm Hg to 123.3 [13.3] mm Hg, P < 0.001 for 24-hour systolic blood pressure [SBP]; from 89.9 [8.2] mm Hg to 76.5 [9.4] mm Hg, P < 0.001 for 24-hour diastolic blood pressure [DBP]. The mean lowering of ambulatory SBP and DBP at peak was 25.2 (14.5) mm Hg and 14.7 (9.5) mm Hg, respectively, and at trough, 22.3 (18.3) mm Hg and 12.3 (10.9) mm Hg. The trough-to-peak ratio of the group was 0.92 for SBP (0.97 in responders) and 0.84 for DBP (0.89 in responders). The smoothness index, calculated as the mean of all individual values, was 1.7 (1.0) for SBP (1.8 [0.9] in responders) and 1.3 (0.8) for DBP (1.5 [0.6] in responders). Seven side effects in 6 patients were reported. No metabolic changes were observed, and no patient discontinued the study because of treatment-related adverse effects.
  
  
  CONCLUSIONS
  The fixed combination of irbesartan 300 mg/HCTZ 25 administered once daily produced a crude meaningful effect in reducing 24-hour blood pressure and was well tolerated. The circadian profile was preserved, as shown by trough-to-peak ratios and smoothness index values for both SBP and DBP.
authors.affiliation: Hospital Clinico IDIBAPS, University of Barcelona, Barcelona, Spain. acoca@clinic.ub.es
authors.forename: Antonio
authors.initials: A
authors.lastname: Coca
authors.forename: Carlos
authors.initials: C
authors.lastname: Calvo
authors.forename: Javier
authors.initials: J
authors.lastname: Sobrino
authors.forename: Elisenda
authors.initials: E
authors.lastname: Gómez
authors.forename: José E
authors.initials: JE
authors.lastname: López-Paz
authors.forename: Cristina
authors.initials: C
authors.lastname: Sierra
authors.forename: Ernesto
authors.initials: E
authors.lastname: Bragulat
authors.forename: Alejandro
authors.initials: A
authors.lastname: de la Sierra
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D001713:Biphenyl Compounds / Q000008:administration & dosage* / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects*; D002940:Circadian Rhythm; D004338:Drug Combinations; D005260:Female; D006801:Humans; D006852:Hydrochlorothiazide / Q000008:administration & dosage* / Q000627:therapeutic use; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D000077405:Irbesartan; D008297:Male; D008875:Middle Aged; D013777:Tetrazoles / Q000008:administration & dosage* / Q000627:therapeutic use
chemical_list: D000959:Antihypertensive Agents; D001713:Biphenyl Compounds; D004338:Drug Combinations; D013777:Tetrazoles; D006852:Hydrochlorothiazide; D000077405:Irbesartan