Angiotensin converting enzyme inhibitors (ACEI) represent the first class of antihypertensive agents that was designed and developed on the basis of a well-defined physiopathological axis of arterial hypertension, a vascular dis order that is now becoming one of the major causes of morbidity/mortality, not only in developed societies but also in the highly populated developing coun tries 1]. CAPTOPRIL, the prototype of the "PRIL" family, which now comprises more than 40 molecule-species, was quite hazardous and the clinical develop ment almost failed when serious side-effects were reported...