ACE inhibitors in the treatment of hypertension in the older patient.

Hypertension is a major potential problem among the increasing number of older persons in the population, threatening their health and shortening their life expectancy due particularly to stroke and congestive heart failure (CHF). Controlled studies have shown that antihypertensive drug therapy reduces the incidence of severe CHF, stroke and cardiovascular mortality in the elderly. Special consideration should be given to altered drug metabolism, altered responses to drugs, and concomitant medications when pharmacotherapy is instituted in the elderly. Angiotensin-converting enzyme (ACE) inhibitors are acceptable in the hypertensive older patient as first-line therapy for all grades of hypertension and as second-line therapy for the patient with CHF. Use of ACE inhibitors avoids many of the symptoms and metabolic disturbances associated with beta-blockers and diuretics. Quinapril is a new non-sulphydryl ACE inhibitor whose active metabolite, quinaprilat, has a relatively short accumulation half-life compared with enalapril and lisinopril but has an enhanced affinity for the converting enzyme, allowing rapid excretion of the drug while retaining a 24-hour antihypertensive effect with once-daily dosing. Quinapril is a valuable addition to the ACE inhibitor class, with demonstrated efficacy and safety in the older patient.