Enalapril maleate is the second angiotensin converting enzyme inhibitor to reach the marketplace. Like captopril, the first entry in this area, enalapril is useful in the treatment of hypertension and congestive heart failure. It has a longer effective half-life than captopril, allowing once or twice-daily dosing, and appears to have a somewhat lower incidence of side effects.
The principle use of enalapril/enalaprilat in veterinary medicine at present is as a vasodilator in the treatment of heart failure. Recent studies have demonstrated that enalapril, particularly when used in conjunction with furosemide, does improve the quality of life in dogs with heart failure. It is not clear, however, whether it has any significant effect on survival times. It may also be of benefit in treating the effects associated with valvular heart disease (mitral regurgitation) and left to right shunts. It is being explored as adjunctive treatment in chronic renal failure and protein losing nephropathies.
While ACE inhibitors are a mainstay for treating hypertension in humans, they have not been particularly useful in treating hypertension in dogs or cats.