Sublingual administration of captopril versus nitroglycerin in patients with severe congestive heart failure

Angiotensin-converting enzyme inhibition has proven to be a successful approach for the long-term treatment of patients with congestive heart failure. This investigation compared the acute hemodynamic changes after sublingual administration of the angiotensin-converting enzyme inhibitor captopril with those after nitroglycerin. A total of 24 patients with severe left heart failure (New York Heart Association classes III and IV) were given 25 mg captopril and 0.8 mg nitroglycerin sublingually in this randomized, cross-over study. Hemodynamic monitoring revealed a clear improvement in pre- and afterload parameters for both drugs (P less than 0.01 and P less than 0.001), while captopril induced a higher increase in cardiac index (+49.2% vs. +25%), stroke volume index (+53.5% vs. +25.7%), and stroke work index (+55% vs. +28%) than nitroglycerin (P less than 0.001). Although not statistically significant, the onset of change for most hemodynamic parameters was measured earlier after nitroglycerin (after 12-19 vs. 16-22 minutes). Captopril revealed later peak effects (after 47-84 vs. 25-55 minutes, P less than 0.001) and a longer sustained improvement in hemodynamic values (return to baseline values after 117-162 vs. 68-120 minutes, P less than 0.001). No side effects occurred after either captopril or nitroglycerin in this study. Thus, these results indicate there is an early improvement in hemodynamic parameters after the sublingual administration of both drugs in patients with severe congestive heart failure, and that captopril induces a more pronounced and prolonged improvement than nitroglycerin.