Efficacy and safety of triamterene/hydrochlorothiazide combinations in mild systemic hypertension

After a 3-week placebo lead-in (Period 1), 78 patients with sitting diastolic blood pressures (BPs) of greater than or equal to 90 and less than or equal to 105 mm Hg entered a 4-week period (Period 2) during which they received triamterene (TMT) 37.5 mg/hydrochlorothiazide (HCTZ) 25 mg/day. Four weeks of therapy with TMT 37.5 mg/HCTZ 25 mg resulted in a statistically significant decrease in mean BP of -15.0/-9.6 mm Hg. Mean BP changed from 145/95 to 130/85 mm Hg. Fifty-nine percent of patients were classified as responders as defined by study criteria. An additional 4 weeks of therapy (Period 3) for responders produced no further change in BP. Nonresponders as a group continued to have a further decrease in BP in Period 3. However, only patients in whom therapy was transferred to TMT 75 mg/HCTZ 50 mg had a statistically significant decrease. All patients who changed to the higher dose combination achieved goal BP by the end of the study. Of the nonresponders who continued to take TMT 37.5 mg/HCTZ 25 mg, 69% achieved goal diastolic BP by the end of Period 3. Three patients were withdrawn because of adverse experiences, 1 of which was considered treatment related. Of 58 reports of adverse experiences, 8 were considered possibly related and 2 probably related to therapy. There was a total of 8 clinically significant abnormal laboratory values, 1 of which was considered to have a possible relation to therapy.