Use of calcium entry blockers in elderly patients. Special considerations

Despite decreasing cardiac mortality rates in the elderly since 1968, rates of health care service use by persons over age 65 years have progressively increased. The growing availability of potent and effective cardiovascular drugs, together with the high prevalence of untoward side effects in the elderly, make it important that we consider the influence of age on cardiovascular response to the calcium entry blockers. The age-related structural, functional, pharmacokinetic, and pharmacodynamic changes that occur in elderly patients suggest that careful monitoring, adjustment, and frequent reassessment of the medical regimen should be performed to minimize untoward effects. Nifedipine, diltiazem, and verapamil are all well absorbed orally, are extensively protein bound, and are metabolized by the liver. The age-associated attenuation in rates of hepatic metabolism and hepatic blood flow contribute to the decreased clearance and prolonged elimination half-lives of these drugs in the elderly. Advanced age can be associated with increased susceptibility to sinoatrial depression, fatigue, constipation, hypotension, and peripheral edema after calcium entry blockade, even at modest doses. It would be prudent, therefore, to administer these agents at lower doses and at less frequent intervals.