title: Antihypertensive activity of angiotensin II AT1 receptor antagonists: a systematic review of studies with 24 h ambulatory blood pressure monitoring.
abstract: OBJECTIVE
  To perform a systematic review of the antihypertensive activity of the angiotensin II AT1 receptor antagonists (ARB).
  
  
  METHODS
  Studies in which blood pressure (BP) was measured using ambulatory BP monitoring for at least 24 h were collected from MEDLINE. Data for each treatment group, ARB, placebo or the drug used for its comparison were obtained from the selected studies. Only studies with a minimum of quality criteria were selected. The final study group contained 36 publications, with a total of 47 patient cohorts receiving ARB in monotherapy, 10 with placebo, 10 with amlodipine, and five with enalapril. The reduction in clinical and ambulatory BP during 24 h, day, night and the last 4-h period for each of the drugs analysed were calculated and adjusted by age, sex, number of participants and by the initial BP level.
  
  
  RESULTS
  The global antihypertensive activity of ARB differs from that observed with amlodipine in the sense that the magnitude of the reduction in the BP values does not essentially depend on the initial BP values nor on the dose used. When only ARB were considered, the drug used was a determinant for systolic BP reduction, whereas for diastolic BP the influence was on the BP reduction and the duration of the antihypertensive activity. The dose used had a particular influence on the duration of the antihypertensive activity for both systolic and diastolic BP.
  
  
  CONCLUSIONS
  Among the ARB, the influence is on duration more than on the magnitude of BP reduction. Dose, therefore, is an important factor in the duration of antihypertensive activity.
authors.affiliation: Hypertension Clinic, Internal Medicine, Hospital Clínico Universitario, Universidad de Valencia, Valencia, Spain.
authors.forename: Maria Jose
authors.initials: MJ
authors.lastname: Fabia
authors.forename: Noelia
authors.initials: N
authors.lastname: Abdilla
authors.forename: Rosa
authors.initials: R
authors.lastname: Oltra
authors.forename: Conrado
authors.initials: C
authors.lastname: Fernandez
authors.forename: Josep
authors.initials: J
authors.lastname: Redon
mesh_terms: D017311:Amlodipine / Q000627:therapeutic use; D047228:Angiotensin II Type 1 Receptor Blockers / Q000627:therapeutic use*; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D018660:Blood Pressure Monitoring, Ambulatory; D004305:Dose-Response Relationship, Drug; D004656:Enalapril / Q000627:therapeutic use; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D016239:MEDLINE; D008297:Male
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D000959:Antihypertensive Agents; D017311:Amlodipine; D004656:Enalapril