title: [Combined fixed doses therapy in systemic hypertension].
abstract: OBJECTIVE
  A single blind clinical trial was conducted to assess the concept that initial treatment in stage I and II of hypertension with fixed doses of two antihypertensives that have different modes of action and additive effects, in a 24-week period with bisoprolol (B), an cardioselective beta blocker, that does not have intrinsic sympathomimetic activity, associated to hydrochlorothiazide (HCTZ).
  
  
  METHODS
  Thirty-one patients (22 females and 9 male) were included, with an age range between 20 and to 70 years (mean 52.45 +/- 12.10). After a two-weeks wash out period and a similar placebo phase, patients were assigned to receive a once-daily dosing of B 5 mg and 6.25 mg of HCTZ, during eight-weeks. Those patients that did not reduce their blood pressure below 90 mm Hg received a double dose of the beta blocker until the end of the study.
  
  
  RESULTS
  After twenty-fourth weeks period of the study, the mean systolic/diastolic blood pressures reduction was 23.9/20.1 mm Hg, compared to basal levels (p < 0.001). The adverse effects were rare. No clinically significant changes from baseline in laboratory parameters were observed.
  
  
  CONCLUSIONS
  This study demonstrates that fixed doses combination therapy with B/HCTZ (5 mg plus 6.25 mg) is effective and well tolerated, with a sustained hypotensive effect. Combined therapy with fixed doses, is an alternative in the initial treatment of mild to moderate hypertension.
authors.affiliation: Hospital de Cardiología, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social. aunzuetamontoya@hotmail.com
authors.forename: Alberto
authors.initials: A
authors.lastname: Unzueta-Montoya
authors.forename: Guillermo
authors.initials: G
authors.lastname: Ordoñez-Toquero
authors.forename: Roberto
authors.initials: R
authors.lastname: Medina-Santillán
mesh_terms: D000959:Antihypertensive Agents / Q000008:administration & dosage*; D017298:Bisoprolol / Q000008:administration & dosage*; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D006852:Hydrochlorothiazide / Q000008:administration & dosage*; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016037:Single-Blind Method
chemical_list: D000959:Antihypertensive Agents; D006852:Hydrochlorothiazide; D017298:Bisoprolol