Calcium channel blockers: An evidence-based review

Calcium channel blockers are widely used in the treatment of cardiovascular disease, but their proper therapeutic role is controversial. Nevertheless, drugs from this class have been evaluated in many controlled clinical trials of adequate size and duration in different patient populations. Although many important questions remain unanswered, these trials have clarified when and how these drugs should be used. In general, the benefits of calcium channel blockers in controlling angina and hypertension are much more clearly documented than are their long term effects on harder end-points such as mortality. Such long term data are sorely needed, particularly for hypertension. An increased risk with dihydropyridine calcium channel blockers has been clearly seen across several studies of patients with coronary disease. In coronary patients with heart failure, the deleterious effects of nifedipine, diltiazem and verapamil outweigh any possible benefit. Long acting formulations and newer calcium channel blockers may not share all of the adverse effects of the older drugs of this class; however, their long term safety has not yet been documented. An understanding of the limitations of calcium channel blockers, based upon clinical trial evidence, often leads the practitioner to choose a drug from another class, where efficacy has been clearly proven.