title: Felodipine extended release versus conventional diuretic therapy for the treatment of systolic hypertension in elderly patients. The National Trial Group.
abstract: OBJECTIVE
  To compare 8 weeks of monotherapy using either felodipine extended release (ER) or a conventional diuretic therapy, triamterene/hydrochlorothiazide (HCTZ), in elderly patients with systolic hypertension.
  
  
  METHODS
  Prospective, randomized, single-blind screening, double-blind treatment, parallel group comparison.
  
  
  METHODS
  Twenty-nine general and family practice sites across Canada.
  
  
  METHODS
  Men and post-menopausal women aged 60 to 85 years, with mild to moderate primary systolic hypertension (systolic blood pressure > 160 mm Hg or blood pressure > 140/ > 90 mm Hg).
  
  
  METHODS
  Daily doses of either felodipine ER (2.5 mg) or triamterene/HCTZ (25/12.5 mg) for 8 weeks. After the first 4 weeks, the patients who responded to the initial dosage (a reduction in systolic blood pressure of at least 15 mm Hg) or whose blood pressure was controlled on the dosage (systolic blood pressure < 140 mm Hg) continued to take the low dose. Among the others, the daily doses were doubled for the final 4 weeks.
  
  
  METHODS
  Systolic blood pressure before beginning treatment and at the end of the study, as well as adverse events and results of heart rate measurement, clinical chemistry tests, electrocardiograms and physical examinations before and after therapy.
  
  
  RESULTS
  Sufficient data for analysis were obtained from 216 patients (86 men and 130 women). Mean seated blood pressure was reduced significantly in both the felodipine group (from 168/91 to 151/84 mm Hg) and the diuretic group (from 168/92 to 147/84 mm Hg). The difference in mean reductions in systolic blood pressure between the groups was 2.2 mm Hg (with a 95% confidence interval of-1.7 to 6.0 mm Hg), which was not significant. Clinical chemistry measurements taken before treatment and at the end of the study showed that more patients in the diuretic group developed abnormal values for blood urea nitrogen, uric acid and creatinine. Other changes were unremarkable. The incidence of adverse events was similar in both groups, but more patients in the felodipine group (9) than in the diuretic group (3) discontinued treatment owing to an adverse event.
  
  
  CONCLUSIONS
  Felodipine ER (2.5 to 5 mg daily) is as effective in reducing systolic blood pressure as triamterene/HCTZ (25/12.5 mg to 50/25 mg daily). More patients discontinued felodipine treatment than triamterene/HCTZ treatment owing to adverse events. However, patients receiving triamterene/HCTZ tended to have abnormal levels in clinical chemistry tests; these should be monitored.
authors.affiliation: Astra Canada, Mississauga, Ont.
authors.forename: W
authors.initials: W
authors.lastname: McClennen
authors.forename: T
authors.initials: T
authors.lastname: Wilson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003692:Delayed-Action Preparations; D004232:Diuretics / Q000627:therapeutic use*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D015736:Felodipine / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D006852:Hydrochlorothiazide / Q000627:therapeutic use*; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D017698:Postmenopause; D011446:Prospective Studies; D016037:Single-Blind Method; D049993:Sodium Chloride Symporter Inhibitors / Q000627:therapeutic use*; D013599:Systole; D014223:Triamterene / Q000627:therapeutic use*; D014665:Vasodilator Agents / Q000627:therapeutic use*
chemical_list: D003692:Delayed-Action Preparations; D004232:Diuretics; D049993:Sodium Chloride Symporter Inhibitors; D014665:Vasodilator Agents; D006852:Hydrochlorothiazide; D015736:Felodipine; D014223:Triamterene