Hemodynamic and Antihypertensive Effects of Captopril, an Orally Active Angiotensin Converting Enzyme Inhibitor

• Published in: Hypertension (Dallas, Tex. 1979) Tex. 1979), 1979-07, Vol.1 (4), p.397-401
• Main Authors: SULLIVAN, JAY M, GINSBURG, BURT A, RATTS, THOMAS E, JOHNSON, JAMES G, BARTON, BEN R, KRAUS, DAVID H, MCKINSTRY, DORIS N, MUIRHEAD, E ERIC
• Format: Article
• Language: English
• Subjects: Adult; Angiotensin-Converting Enzyme Inhibitors; Blood Pressure - drug effects; Captopril - administration & dosage; Captopril - adverse effects; Captopril - pharmacology; Drug Evaluation; Female; Hemodynamics - drug effects; Humans; Hydrocortisone - blood; Hypertension - blood; Hypertension - drug therapy; Hypertension, Renovascular - blood; Hypertension, Renovascular - drug therapy; Male; Middle Aged; Potassium - metabolism; Proline - analogs & derivatives; Renin - blood; Sodium - metabolism
• ISSN: 0194-911X; 1524-4563
• DOI: 10.1161/01.HYP.1.4.397

SUMMARY Captopril inhibits angiotensin II formation and bradyklnin degradation in vivo. Eleren patients with essential hypertension (EH) and four patients with renovascular hypertension (RVH) were treated with captopril for periods ranging from 3 days to 12 months. All patients had a diastolic blood pressure (DBP) over 95 ram Hg after receiving a placebo for 3 days. Captopril given in ascending doses (10-1000 mg/day) caused normalization of blood pressure in all but three patients, one with serere RVH whose pressure fell 11%, one patient with severe EH, whose pressure fell 27%, and one with EH whose Mood pressure fell 8.5%. The average control DBP in patients with EH was 113.7 ± 5.5 (SE) mm Hg and feU to 89.9 ± 3.6 mm Hg (< 0.001), while DBP in patients with RVH fell from 110.7 ± 7.6 mm Hg to 943 ± 8.2 (p < 0.005). All patients were studied in balance on a 100 mEq sodium (Na) diet Plasma renln activity (PRA) versus 24-bour urinary Na excretion increased sevenfold during therapy while converting enzyme activity fell by about one half. The magnitude of the blood pressure response was not related to control PRA. Cardiac output was estimated by ecnocardiography during placebo administration and during maintenance therapy with captopril. A significant change was not observed. Total peripheral resistance fell an average of 18.9% (p < 0.05) in 11 of the 13 patients in whom the measurement could be made. It is concluded that captopril effectively lowers Mood pressure in patients with EH or RVH by reducing total peripheral resistance.