Document Detail

Effects of chronic clonidine administration on sympathetic nerve traffic and baroreflex function in heart failure.
MedLine Citation:
PMID:  11509491     Owner:  NLM     Status:  MEDLINE    
Congestive heart failure is characterized by a sympathetic activation that is coupled with a baroreflex impairment. Whether these alterations are affected by clonidine is unknown. In 26 normotensive patients age 58.0+/-1.1 years (mean+/-SEM) affected by congestive heart failure (New York Heart Association functional class II or III) and treated with furosemide and enalapril, we measured mean arterial pressure, heart rate, venous plasma norepinephrine, and muscle sympathetic nerve traffic (microneurography) at rest and during baroreceptor stimulation and deactivation caused by stepwise intravenous infusions of phenylephrine and nitroprusside, respectively. Measurements were repeated after a 2-month administration of transdermal clonidine patch (14 patients) or placebo (12 patients) according to a double-blind, randomized sequence. Clonidine caused a slight, nonsignificant reduction in mean arterial pressure and heart rate without affecting exercise capacity and echocardiographically determined left ventricular ejection fraction. In contrast, both plasma norepinephrine and sympathetic nerve traffic were significantly reduced (-46.8% and -26.7%, respectively; P<0.01 for both). This reduction was coupled with no change in cardiac and sympathetic baroreflex responses. Transdermal placebo administration for a 2-month period did not affect any of the above-mentioned variables. Thus, in congestive heart failure patients who are undergoing conventional drug treatment, chronic clonidine administration exerts marked sympathoinhibitory effects without adversely affecting cardiac functions and clinical state. Whether this leads to further therapeutic benefits remains to be tested.
G Grassi; C Turri; G Seravalle; G Bertinieri; A Pierini; G Mancia
Publication Detail:
Type:  Clinical Trial; Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Hypertension     Volume:  38     ISSN:  1524-4563     ISO Abbreviation:  Hypertension     Publication Date:  2001 Aug 
Date Detail:
Created Date:  2001-08-17     Completed Date:  2001-08-30     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  7906255     Medline TA:  Hypertension     Country:  United States    
Other Details:
Languages:  eng     Pagination:  286-91     Citation Subset:  IM    
Clinica Medica, Università Milano-Bicocca, Ospedale San Gerardo, Monza (Milan), Italy.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Baroreflex / drug effects*
Blood Pressure / drug effects
Clonidine / administration & dosage,  pharmacology*
Double-Blind Method
Heart Failure / blood,  drug therapy,  physiopathology*
Heart Rate / drug effects
Middle Aged
Nitroprusside / pharmacology
Norepinephrine / blood
Phenylephrine / pharmacology
Sympathetic Nervous System / drug effects*
Sympatholytics / administration & dosage,  pharmacology*
Reg. No./Substance:
0/Sympatholytics; 15078-28-1/Nitroprusside; 4205-90-7/Clonidine; 51-41-2/Norepinephrine; 59-42-7/Phenylephrine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Role of nNOS in regulation of renal function in angiotensin II-induced hypertension.
Next Document:  Negative inotropic and chronotropic effects of oxytocin.