Efficacy, tolerability and influence on "quality of life" of nifedipine GITS versus amlodipine in elderly patients with mild-moderate hypertension

Objective: The main purpose of this study was to compare efficacy, tolerabi lity and influence on quality of life (QOL) of nifedipine gastrointestinal therapeutic system (NI) 30-60 mg once a day vs amlodipine (AM) 5-10 mg once a day in elderly patients with mild-moderate hypertension. Design: This wa s a randomized, double-blind, parallel-group, multicenter study. After a 2- week single-blind placebo run-in, patients were randomized to either NI 30 mg or AM 5 mg. Responders continued on the same dosage for 16 additional we eks, while non-responders were titrated to 60 mg NI or 10 mg AM. Methods: B lood pressure was measured by mercury sphygmomanometer and efficacy equival ence of NI and AM tested by covariance analysis. Diastolic blood pressure ( DBP) was the primary efficacy parameter, its baseline value being taken as covariate while centers effect and treatment interaction were included as f ixed effects in the analysis model. The secondary efficacy variables systol ic blood pressure (SBP) and scores for QOL were analyzed according to the s ame model. Results: At the end of the study, overall mean DBPs, calculated as least-square means (LSMEANS), in the "by protocol" population were 87.5 mmHg for NI and 86.7 for AM (difference 0.8 mmHg with 90% Cl -1.2 to 2.8 mm Hg). In the "by intention to treat" (ITT) population LSMEANS were 87.6 mmHg for NI and 86.4 mmHg for AM (difference 1.2 mmHg with 90% CI -0.6 to 3.1 m mHg). SBP LSMEANS in the "by protocol" population were 147.7 mmHg for NI an d 147.3 mmHg for AM (difference 0.3 mmHg, with 90% Cl -3.7 to 4.3); corresp onding values in the "by ITT" population were 148.0 mmHg for NI and 147.2 f or AM (difference 0.8 mmHg, with 90% CI -2.8 to 4.6). Mean values for QOL p arameters were not significantly different. A total of 173 episodes of adve rse events were documented in 54 patients (26 NI and 28 AM), dropouts were 15 (20% of group) on NI and 21 (28%) on AM. Conclusions: NI 30-60 mg was sh own to be as efficacious and safe as AM 5-10 mg in elderly patients with mi ld-moderate hypertension. QOL improved compared to baseline with no signifi cant difference between the two drugs, thus confirming a positive class eff ect for calcium antagonists.