Use of Calcium Channel Antagonists for the Treatment of Hypertension in the Elderly

Metabolic effects of manidipine

The calcium channel antagonists (CCAs) were originally introduced as vasodilators for the treatment of coronary heart disease, but are now also noted for their clinical efficacy in the management of hypertension. Data from large clinical studies have shown that CCAs are not associated with the undesirable metabolic effects (e.g. worsening of dyslipidemia and reduction of insulin sensitivity) seen with older agents such as thiazide diuretics and beta-adrenoceptor antagonists (beta-blockers) that are used to treat hypertension. Indeed, reductions in cardiovascular risk and rates of onset of new cases of diabetes mellitus have been reported in trials in patients with hypertension treated with CCAs. These beneficial effects extend beyond those expected to accompany reductions in BP. Until recently, the biochemical effects underlying these metabolic changes were only poorly understood, but pharmacologic studies have now started to shed more light on these issues. Of particular interest are studies with manidipine, some of which suggest that this agent may be associated with greater improvements in insulin sensitivity and may have better renal protective properties than other CCAs. Confirmation of potential differences among CCAs in terms of the relative magnitude of any beneficial metabolic effects requires further study. Ongoing research is expected to clarify further the action of these agents at the cellular level and to assist with the optimization of antihypertensive therapy, particularly in patients with elevated cardiovascular risk profiles.

Calcium channel blockers: monotherapy and dual therapy considerations in the treatment of hypertension

The papers in this supplement speak to several of the issues pertinent to contemporary therapy with CCBs. The article by Dr Weir thoughtfully describes important pharmacokinetic and pharmacodynamic features of CCBs. In so doing he establishes the basis for combination CCB and ACE inhibitor therapy. Dr Frishman provides a scholarly description of the cardiovascular effects of CCBs and further elaborates on the distinctiveness of the various CCB subclasses. Finally, Dr Bakris et al. provides data from INVEST (INternational VErapamil-Trandolapril STudy), which shows the particular utility of a CCB and ACE inhibitor combination in bringing elderly hypertensive patients with CAD to goal BP when monotherapy

Comparison of blood pressure control with amlodipine and controlled-release isradipine: an open-label, drug substitution study

An open-label drug substitution study showed that controlled-release isradipine (Dynacirc-CR) can be safely substituted for amlodipine on a mg-for-mg basis in patients with mild-to-moderate hypertension. When controlled-release isradipine was substituted for amlodipine, blood pressure was more effectively controlled, and edema rates were reduced. When subjects resumed amlodipine therapy, the previous gain in blood pressure reduction and lessening of edema vanished. The basis for this more favorable pattern of efficacy and side-effects with controlled-release isradipine, although mechanistically unresolved, may relate to a lesser degree of sympathetic nervous system activation.