PINACIDIL AND HYDROCHLOROTHIAZIDE ALONE OR IN COMBINATION IN THE TREATMENT OF HYPERTENSION IN THE ELDERLY

Pinacidil (PIN) is a new antihypertensive cyanoguanidine derivative co mpound classified as a potassium channel opener, This double-masked, r andomized, controlled clinical study compared the antihypertensive eff icacy of PIN 25 mg alone, hydrochlorothiazide (HCTZ) 12.5 mg alone, an d PIN 12.5 mg + HCTZ 12.5 mg, all given once a day, Eighty-four elderl y outpatients (39 men, 45 women; mean age, 77.5 +/- 5.5 years) with mi ld or moderate hypertension (diastolic blood pressure between 95 and 1 15 mm Hg) mere randomly assigned to one of the three treatment groups, After a 3-week placebo run-in period, patients received the active dr ug at 8 AM daily for 8 weeks, Office blood pressure (BP) measurements were performed at baseline and at 1, 2, 4, and 8 weeks, Ambulatory BP monitoring (ABPM) was performed for 24 hours (from 7 AM to 7 AM of the next day) at baseline and at the end of the treatment period, At the end of 8 weeks, 62 patients (73.8%) had normal BP (20 patients [71.4%] treated with PIN, 19 patients [67.9%] treated with HCTZ, and 23 patie nts [82.1%] treated with PIN + HCTZ). The classification of the patien ts as responders or nonresponders showed that all three treatments wer e effective, with a Slight advantage for the combination therapy (26 r esponders [92.8%]) over HCTZ alone (24 responders [85.7%]) and PIN alo ne (22 responders [78.6%]). However, differences between the groups me re not significant, Ambulatory BPs were significantly reduced in all g roups, Patients receiving HCTZ alone and PIN + HCTZ achieved good BP c ontrol that was persistent. over the 24 hours, whereas patients receiv ing PIN alone failed to achieve a significant reduction in nighttime B P, Heart rate was reduced in patients in the HCTZ and PIN + HCTZ Group s (7.2% and 5.7%, respectively), whereas it was only slightly changed in patients in the PIN group (1.4%). All drug regimens were well toler ated; only 11 patients complained of mild or moderate side effects, an d no patient discontinued treatment. In conclusion, combination therap y with PIN 12.5 mg + HCTZ 12.5 mg, given once a day, appears to provid e effective and well-tolerated 24-hour BP control in elderly hypertens ive patients.