Summary
The haemodynamic effects of enalapril (EN), a new, long-acting, nonsulphhydryl converting enzyme inhibitor, were evaluated by non-invasive methods in 10 adult patients with mild to moderate essential hypertension (EH). Patients were randomly assigned, double blind to 2 treatment groups (EN 20 mg o.d. or 10 mg b.d.) for 4 weeks, and were crossed over to the other dosage regimen after a 2-week washout period. Measurements included mean arterial pressure (MAP), heart rate (HR), cardiac output (CO), limb blood flow (LBF), plasma aldosterone (ALD), plasma renin activity (PRA) and systolic time intervals (STI). Both regimens (b.d. and o.d.) significantly reduced MAP (15.3% and 16.3%, respectively), total peripheral resistance (20.3% and 21.8%, respectively), limb vascular resistance (24.1% and 24.9%) and ALD (33.5% and 36.9%) and increased CO (7.8% and 8.7%), LBF (10.9% and 11.6%) and PRA (10.4% and 9.5%). No significant change was observed in HR or STI. EN 20 mg o.d. or 10 mg b.d. reduced arterial pressure to a similar extent through a fall in total peripheral resistance. An increase in CO was also observed.
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Antonaccio MJ, Rubin B, Horovitz ZP (1980) Cardiovascular pharmacology of captopril, an orally active inhibitor of angiotensin converting enzyme. Drug Exp Clin Res 6: 19–32
Bravo EL, Tarazi R (1979) Converting enzyme inhibition with an orally active compound in hypertensive man. Hypertension 1: 39–46
Gavras H, Brunner HR, Turini GA, Kershaw GR, Tifft CP, Cuttelod S, Gavras I, Vukovich RA, Mckinstry DN (1978) Antihypertensive effects of the oral angiotensin converting enzyme inhibitor SQ 14225 in man. N Engl J Med 298: 991–995
Gomez HJ, Cirillo VJ (1983) Angiotensin converting enzyme inhibitors: The clinical pharmacology of captopril and enalapril maleate. In: Velasco M (ed) Clinical pharmacology and therapeutics. (Intl. Congress Series No. 604). Excerpta Medica, Amsterdam, pp 52–57
Gomez HJ, Cirillo VJ, Jones KH (1985) The clinical pharmacology of enalapril. J Hypertens (in press)
Rubin B, Antonaccio MJ (1980) Captopril. In: Scriabine A (ed). Pharmacology of antihypertensive drugs. Raven Press, New York, pp 21–42
Atkinson AB, Robertson JIS (1979) Captopril in the treatment of clinical hypertension and cardiac failure. Lancet 2: 838–839
Clogh IP, Conway J, Hatton R, Scott KL (1979) The effect of angiotensin converting enzyme inhibitor on baroreceptor reflexes in conscious dogs during sodium depletion. J Physiol (Lond) 195: 75–76
Gross DM, Sweet CS, Ulm E, Blacklund EP, Morris AA, Weitz D, Bohn DL, Wenger HC, Vassil TC, Stone CA (1981) Effect of N-(S)-1-carboxy-3-phenylpropyl-L-ala-L-L-Pro and its ethyl ester (MK-421) on angiotensin converting enzyme in vitro and angiotensin I pressor responses in vivo. J Pharmacol Exp Ther 216: 552–557
Patchett AA, Harris E, Tristam EW, Wyuratt MJ, Wu MT, Gaub D, Peterson ER, Ikeler TJ, Ten Broecke J, Payne LJ, Ondeyk DL, Thurbelt ED, Greenlee WJ, Lohr NS, Hoffsommer RD, Hoshua J, Ruyle WV, Rothrock JW, Aster SD, Maycock SL, Robinson FM, Hirschmann R, Sweet CS, Ulm EH, Gross DM, Vassic TC, Stone CA (1980) A new class of angiotensin converting enzyme inhibitors. Nature 288: 280–283
Sweet CS, Gross DM, Arbegast PT, Gaul SL, Britt PM, Ludden CT, Weitz D, Stone CA (1981) Antihypertensive activity of N-(5)-1-(ethoxycardonyl)-3-phenylpropyl-1-ala-L-pro (MK-421), an orally active converting enzyme inhibitor. J Pharmacol Exp Ther 216: 558–566
Biollaz J, Burnier M, Turini GA, Brunner DB, Porchet M, Gomez HJ, Jones KH, Ferber E, Abrams WB, Gavras H, Brunner HR (1981) Three new long-acting converting-enzyme inhibitors: relationship between plasma converting enzyme activity and response to angiotensin I. Clin Pharmacol Ther 29: 665–670
Weissler AM, Garrad CL (1971) Systolic time intervals in cardiac disease. Mod Concepts Cardiovasc Dis 40: 1–8
Kubicek WG, Karnegis JN, Patterson RP, Witsoe DA, Mattson RM (1966) Development and evaluation of an impedance cardiac output system. Aerospace Med 37: 1208–1212
Labadidi S, Ehmke DA, Durmin RE, Leaverton PE, Lauer RM (1971) Evaluation of impedance cardiac output in children. Pediatrics 47: 870–879
Robie NW, Blumenstein BA, McNay JL (1985) Impedance cardiography as an index of change in cardiac output. J Appl Physiol (in press)
Greenfield ADM, Whitney RH, Mowgray GF (1963) Method for the investigation of peripheral blood flow. Br Med Bull 19: 101–109
Haber E, Koener T, Page LB, Klinan BB, Purnode A (1969) Application of radioimmunoassay for angiotensin I to the physiological measurements of plasma renin activity in normal subjects. J Clin Endocrinol Metab 29: 1349–1355
Fraser R, Guest S, Young J (1973) Comparison of doble isotope derivative and radioimmunological estimation of plasma aldosterone concentration. Clin Sci Mol Med 45: 411–415
Snedecor GW, Cochran WE (1971) Statistical method, 6th edn. Ames Iowa State University Press
Bergstrand R, Johansson S, Vedin A, Wihelmsson C (1982) Comparison of once-a-day and twice-a-day dosage regimens of enalapril (MK-421) in patients with mild hypertension. Br J Clin Pharmacol 14: 136P
Takata IY, Dinocolantonio R, Hutchinson J, Mendelsohn F, Doyle A (1982) In vivo comparison of three orally active inhibitors of angiotensin converting enzyme. Am J Cardiol 49: 1502–1504
Ibsen H, Egar B, Osterziel K, Vander A, Julius S (1983) Reflex hemodynamic adjustments and baroreflex sensitivity during converting enzyme inhibition with MK-421 in normal humans. Hypertension 5 [Suppl 1]: 184–191
Morganti A, Pickering TG, Lopez-Ovejero JA, Laragh JH (1980) Endocrine and cardiovascular influence of converting enzyme inhibition with SQ 14225 in hypertensive patients in the supine position and during head-up tilt before and after sodium depletion. J Clin Endocrinol Metab 50: 748–754
Antonaccio M, McGill M (1982) Comparative effects of captopril and MK-421 on sympathetic function in spontaneously hypertensive rats. Am J Cardiol 49: 1533–1534
Bravo EL, Tarazi RC (1978) Hemodynamics of an angiotensin II antagonist in normal unanesthetized dogs. Circ Res 43 [Suppl 1]: 27–31
Campbell BC, Sturani A, Lawrie CB, Reid RL (1983) Evidence of parasymphathetic activity of captopril in normotensive man (abstract). 1st European Meeting on Hypertensive (Milan). Rec Sc Educ Perm [Suppl] 33: 54
Hodsman GP, Brown JJ, Davies DL (1982) Converting enzyme inhibitor enalapril (MK-421) in the treatment of hypertension with renal artery stenosis. Br Med J 285: 1697–1699
Hodsman GP, Brown JJ, Cumming AMM (1983) Enalapril (MK-421) in the treatment of hypertension with renal artery stenosis. J Hypertens (in press)
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Velasco, M., Silva, H., Morillo, J. et al. Haemodynamic effects of enalapril, a new converting enzyme inhibitor, in hypertensive patients. Eur J Clin Pharmacol 29, 17–20 (1985). https://doi.org/10.1007/BF00547362
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DOI: https://doi.org/10.1007/BF00547362