Optimal dosage of ACE inhibitors in older patients.

Despite having lower levels of plasma renin activity than younger individuals, elderly patients with hypertension respond well to ACE inhibitors and the drugs have few adverse effects. Plasma concentrations of the active ACE inhibitor are generally higher in the elderly because of decreased renal clearance. These altered pharmacokinetics, combined with impairment of cardiovascular reflexes and the increasing prevalence of heart failure and renal impairment with age, render elderly patients more susceptible to first-dose hypotension. Although many studies have shown that standard dosages are well tolerated it is safer to use lower initial dosages of ACE inhibitors in elderly hypertensive patients because hypotensive reactions are not always predictable. The maintenance dosage may be determined more by the presence of renal disease or heart failure than by age per se. In elderly patients with heart failure, ACE inhibitors should be introduced even more cautiously, using low dosages and preferably under supervision. It may also be necessary to interrupt diuretic treatment for a few days to prevent severe hypotension. The ACE inhibitor dosage should then be titrated up to the maximum that is well tolerated, as this appears to offer the greatest benefit.