Linked Life Data

2581072

Source:http://linkedlifedata.com/resource/pubmed/id/2581072

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1985-6-18
pubmed:abstractText
The relationships between steady-state plasma concentrations of verapamil or nifedipine and the resultant hemodynamic and electrophysiologic effects were evaluated in anesthetized, instrumented dogs. In different groups of animals, the drugs were given intravenously by loading-maintenance infusions designed to rapidly achieve and sustain stable plasma drug concentrations, over four different target ranges which span those found in clinical use of these agents. Plasma levels of nifedipine varied from 5 to 125 ng/ml, and those of verapamil, from 40 to 500 ng/ml. Nifedipine produced no apparent effects on the surface electrocardiogram. Verapamil dosing resulted in progressive prolongation of the PR interval as plasma drug levels increased from 40 to 250 ng/ml; at higher drug levels, complete atrioventricular block occurred. At the highest plasma concentrations used, the maximal vasodilation produced by both drugs was approximately equal, with mean aortic pressure levels falling to 50-60% of control values. The effects of the two agents on cardiac pump performance, however, differed: nifedipine administration produced dose-related increases in cardiac output at all plasma drug concentrations studied; the effects of verapamil were critically dependent upon drug levels in plasma, with cardiac output increased above control values at drug concentrations between 40 and 250 ng/ml, and progressively depressed at higher plasma levels of the drug. As a result, the calculated systemic vascular resistance declined progressively during nifedipine administration, while after verapamil doses, this parameter varied inversely with observed effects on cardiac output.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0160-2446
pubmed:author
pubmed:issnType
Print
pubmed:volume
7
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
224-31
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:articleTitle
Pharmacodynamic comparison of verapamil and nifedipine in anesthetized dogs.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't