Choosing the Right ACE Inhibitor: A Guide to Selection

To find out if there are one or more criteria to guide selection among the ACE inhibitors for the treatment of arterial hypertension, we have reviewed the principal pharmacokinetic and pharmacodynamic aspects of the more frequently used agents of this class of antihypertensive drugs. Among the pharmacokinetic aspects that we have considered, terminal half-life, as related to the duration of the antihypertensive effect, and the route of elimination may have an impact in the clinical selection among the various ACE inhibitors. On the other hand, all the other characteristics have no pragmatic clinical relevance or may be corrected by dosage adjustment. Among the pharmacodynamic aspects, the antihypertensive efficacy of the different ACE inhibitors seems to be very similar, and some of the differences found in different studies are probably due to the population investigated and to the protocol of the study (time of blood pressure measurements, diet, drug dosage etc.). However, some differences can be found among the various ACE inhibitors when the antihypertensive efficacy is evaluated also as trough to peak ratio of blood pressure reduction. Indeed, in respect of the administration schedule of each ACE inhibitor not all the agents of this class have a trough to peak ratio above 50 to 60%, as suggested by the Food and Drug Administration of the US. According to this criterion, especially when blood pressure is measured with 24-hour noninvasive ambulatory blood pressure monitoring, some drugs such as lisinopril, enalapril and trandolapril should be preferred for their higher trough to peak ratios. Left ventricular hypertrophy is significantly reduced by antihypertensive agents, the ACE inhibitors being the most effective. Indeed, the reduction of left ventricle mass for each 1 mm Hg reduction in mean blood pressure is greater for ACE inhibitors than for other classes of antihypertensive agents. However, this effect seems more class related than characteristic of one or more among the various ACE inhibitors. Insulin resistance is elevated in hypertensive patients and it has been thought responsible for or associated with other metabolic abnormalities. ACE inhibitors seem to correct the insulin resistance of hypertensive patients, but this effect also appears to be class related more than limited to one ACE inhibitor or another. Our knowledge of this field is still limited and more studies are necessary, especially to understand the prognostic impact of insulin resistance and/or insulin resistance improvement