This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wood, A. J. Articles by Wood, M. Search for Related Content PubMed PubMed Citation Articles by Wood, A. J. Articles by Wood, M.

Circulation, Vol 62, 1119-1122, Copyright © 1980 by American Heart Association

ARTICLES

Elevated plasma free drug concentrations of propranolol and diazepam during cardiac catheterization

AJ Wood, D Robertson, RM Robertson, GR Wilkinson and M Wood

Patients who undergo cardiac catheterization are frequently taking propranolol and are often premedicated with diazepam. Because the intensity of a drug's action is determined by free, or non-protein- bound, levels in plasma, changes in the degree of protein binding may profoundly alter the pharmacologic effect. We examined the effects of heparin on the free levels of propranolol and diazepam in six patients who underwent cardiac catheterization. After heparinization, the free fraction of diazepam increased more than fourfold, from 1.8 +/- 0.1% to 7.9 +/- 1.2% (p < 0.002) and the free levels increased from 2.0 +/- 0.5 to 8.4 +/- 2.2 ng/ml (p < 0.025); the free fraction of propranolol increased from 7.4 +/- 0.9% to 12.5 +/- 1.4% (p < 0.001). The increase in free drug concentration was associated with elevated free fatty acid levels, which rose from 181 +/- 7 micrograms/ml to 596 +/- 119 micrograms/ml (p < 0.02). Increases in the free levels of propranolol and diazepam produced by heparinization during cardiac catheterization may result in increased pharmacolaogic effect, such as excessive sedation or respiratory depression.

This article has been cited by other articles:

				S. Wolvek The Evolution of the Intra-Aortic Balloon: The Datascope Contribution J Biomater Appl, January 1, 1988; 3(4): 527 - 543. [Abstract] [PDF]