Nifedipine and mortality risk in the elderly: relevance of drug formulation, dose and duration.

Purpose: This study examines the risk of all-cause and cardiac-related mortality associated with calcium channel blockers (CCBs) and other antihypertensives/diuretics compared with beta-blockers among an elderly cohort. We explored variations in mortality risk according to CCB formulation, dose and duration of use.

Methods: Data are from the clinical sample of the Canadian Study of Health and Aging, a population-based prospective study of community and institutional residing persons aged 65+ years. The sample comprised 837 subjects without dementia and reporting use of 1+ antihypertensive/diuretic agents at baseline (1991) and with survival data during follow-up (1996).

Results: Risk of all-cause and cardiac-related mortality was significantly higher among nifedipine users (HR=1.85, 95%CI 1.12, 3.05 and HR=2.22, 95%CI 1.02, 4.84, respectively) compared with beta-blocker users. After adjusting for covariates, the hazard ratios (95% confidence interval) for selected drug classes compared with beta-blockers were: nifedipine HR=1.82 (1.09-3.04), diltiazem/verapamil HR=0.96 (0.58-1.60), loop diuretics HR=1.84 (1.21-2.82), ACE inhibitors HR=0.98 (0.54-1.78) and other diuretics/antihypertensives HR=1.10 (0.70-1.72). Among nifedipine users, mortality risk increased with average daily dose and with recent (
Conclusions: Older subjects exposed to the dihydropyridine calcium antagonist nifedipine had a significantly higher risk for all-cause and cardiac-related mortality during the 5-year follow-up than subjects using beta-blockers. Copyright (c) 2000 John Wiley & Sons, Ltd.