A single dose study of the effects of fenoldopam and enalapril in mild hypertension.
To clarify the contribution made by the renin-angiotensin system activation to the short lived hypotensive response to fenoldopam, the haemodynamic effects of a combination of fenoldopam (100 mg) and enalapril (5 mg) were compared with fenoldopam alone, enalapril alone and placebo in a balanced, randomised, double blind, single dose study in eight hypertensive patients. Fenoldopam caused an acute fall in blood pressure which lasted approximately 3 h after dosing and was associated with a reflex tachycardia. Enalapril caused a more gradual fall in blood pressure (onset 2 h) without a reflex tachycardia. The combination of drugs produced greater reductions in blood pressure sustained for a longer period than fenoldopam alone and with a more rapid onset than enalapril alone. In combination the hypotensive effects of fenoldopam and enalapril were clearly additive and not synergistic. Activation of the renin-angiotensin system does not antagonise significantly the hypotensive effect of fenoldopam.
Department of Clinical Pharmacology, Royal Infirmary, Edinburgh, UK.
T M
TM
MacDonald
R F
RF
Jeffrey
S
S
Freestone
M R
MR
Lee
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D003404:Creatinine / Q000378:metabolism; D015259:Dopamine Agents / Q000627:therapeutic use*; D004311:Double-Blind Method; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D004656:Enalapril / Q000627:therapeutic use*; D018818:Fenoldopam; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008875:Middle Aged; D009318:Natriuresis / Q000187:drug effects; D011187:Posture / Q000502:physiology; D011674:Pulse / Q000187:drug effects
D015259:Dopamine Agents; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D004656:Enalapril; D003404:Creatinine; D018818:Fenoldopam