Clinical and hemodynamic experience with enalapril in congestive heart failure.
The renin-angiotension system is activated in many patients with congestive heart failure (CHF), resulting in angiotensin-mediated vasoconstriction and aldosterone-mediated sodium and water retention. To evaluate the effectiveness of enalapril, a new converting enzyme inhibitor, enalapril was administered to patients either orally or intravenously in a single dose, and hemodynamic and hormonal responses were measured. Patients were then placed on oral enalapril therapy for 1 month, and treadmill exercise duration and invasive hemodynamics were compared with baseline pretreatment data. With single-dose administration, both oral and intravenous enalapril reduced systemic vascular resistance and increased cardiac output. However, the effects of oral enalapril were not manifest for 3 to 4 hours, because oral enalapril is a pro-drug form that requires hepatic deesterification. In contrast, intravenous enalapril resulted in significant hemodynamic and hormonal changes 15 to 30 minutes after administration. During long-term therapy, enalapril was associated with improved symptomatology, increase of treadmill exercise duration and sustained hemodynamic improvement. Enalapril was effective therapy for chronic CHF. Optimal short-term response may require coadministration of both intravenous and oral preparations of enalapril; however, the magnitude of the short-term response was comparable for both preparations. Long-term therapy is most effective when the drug is administered as a twice-daily regimen.
Cody
R J
RJ
D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000450:Aldosterone / Q000097:blood; D001794:Blood Pressure / Q000187:drug effects; D004151:Dipeptides / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D004656:Enalapril; D004791:Enzyme Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011669:Pulmonary Wedge Pressure / Q000187:drug effects; D012083:Renin / Q000097:blood; D012084:Renin-Angiotensin System / Q000187:drug effects; D013318:Stroke Volume / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects
D004151:Dipeptides; D004791:Enzyme Inhibitors; D000450:Aldosterone; D004656:Enalapril; D012083:Renin