COMPARISON OF NIFEDIPINE GITS AND HYDROCHLOROTHIAZIDE IN THE MANAGEMENT OF ELDERLY PATIENTS WITH STAGE I-III DIASTOLIC HYPERTENSION

A randomized, double blind, parallel study was performed to compare th e effects of nifedipine gastrointestinal therapeutic system (GITS) to hydrochlorothiazide (HCTZ) in the management of the elderly hypertensi ve. Eighteen patients, mean age 65 +/- 5 years, with Stage I-III diast olic hypertension (sitting diastolic BP between 90 and 115 mm Hg) were included in each treatment group. Following a 2 to 8 week placebo was hout phase, patients received either nifedipine GITS or HCTZ and were titrated over 5 weeks to achieve a goal diastolic blood pressure less than 90 mm Hg. Patients were then continued on medication during an 8 week maintenance phase. Treatment effect on systolic and diastolic blo od pressure was assessed. Serum electrolytes, lipids, blood urea nitro gen, and creatinine were measured before and after treatment. Posttrea tment changes in renal and cardiovascular function, as well as left ve ntricular mass were evaluated. The results showed significant reductio ns in systolic and diastolic blood pressure with both drugs; no treatm ent difference was found, although goal blood pressure was achieved mo re rapidly with nifedipine GITS (28 v 34 days, P <.05). BUN was signif icantly increased only after diuretic therapy (P <.01) and serum potas sium fell to a greater degree with HCTZ (0.3 mEq/L v 0.1 mEq/L) than w ith nifedipine GITS. No statistically significant changes in left vent ricular mass, ejection fraction, glomerular filtration rate, or renal blood now were seen after therapy with either drug. However, the time to peak LV diastolic filling rate decreased with nifedipine GITS (197 to 164 msec) and increased with HCTZ (172 to 198 msec). This treatment difference approached statistical significance (P =.07). Adverse side effects of treatment were reported by 50% of nifedipine GITS patients and 28% of patients treated with HCTZ. This treatment difference was not statistically significant. We conclude that both nifedipine GITS a nd HCTZ monotherapy provide significant blood pressure reduction in ol der hypertensives with Stage I-III diastolic hypertension. Both drugs are well tolerated with no significant adverse effect on renal or card iovascular function after short term therapy.