This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map 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 Hui, T. P. Articles by Yeager, K. Search for Related Content PubMed PubMed Citation Articles by Hui, T. P. Articles by Yeager, K. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Hazardous Substances DB CLONIDINE EPINEPHRINE HYDROCHLOROTHIAZIDE POTASSIUM SODIUM Medline Plus Health Information High Blood Pressure

Hypertension, Vol 8, 272-276, Copyright © 1986 by American Heart Association

ARTICLES

Diuretic treatment alters clonidine suppression of plasma norepinephrine

TP Hui, LR Krakoff, K Felton and K Yeager

The effect of short-term diuretic treatment on the action of clonidine was evaluated in eight subjects with mild, uncomplicated hypertension. A single oral dose of clonidine (0.3 mg) was given before and after 1 week of therapy with hydrochlorothiazide, 50 mg, and amiloride, 5 mg, taken daily. Changes in mean arterial pressure, heart rate, plasma norepinephrine and epinephrine levels, and plasma renin activity were assessed. Diuretic treatment caused a significant weight loss, increased plasma renin activity, and reduced serum potassium concentration but did not significantly alter the absolute reduction in mean arterial pressure caused by clonidine. Absolute clonidine-induced reduction in plasma renin activity after diuretic treatment was three times greater than before treatment, although percent changes were similar. Before diuretic therapy, clonidine significantly reduced the level of norepinephrine (absolute and percent change). After diuretic treatment, clonidine failed to suppress norepinephrine, and the difference from prediuretic changes was significant. The level of epinephrine was not altered significantly either by diuretic treatment or clonidine. These results indicate that diuretic therapy alters the clonidine-activated mechanism for reduction of arterial pressure through a shift from overall suppression of sympathetic tone to pathways that are more restricted to renal tone. This shift may be due to changes in fluid or electrolyte balance that alter the action of alpha 2-adrenergic receptor-mediated pathways. Use of the clonidine suppression test for the diagnosis of pheochromocytoma may give false- positive results in diuretic-treated patients.

This article has been cited by other articles:

				G. Eisenhofer, D. S. Goldstein, M. M. Walther, P. Friberg, J. W. M. Lenders, H. R. Keiser, and K. Pacak Biochemical Diagnosis of Pheochromocytoma: How to Distinguish True- from False-Positive Test Results J. Clin. Endocrinol. Metab., June 1, 2003; 88(6): 2656 - 2666. [Abstract] [Full Text] [PDF]

				K. Pacak, W. M. Linehan, G. Eisenhofer, M. M. Walther, and D. S. Goldstein Recent Advances in Genetics, Diagnosis, Localization, and Treatment of Pheochromocytoma Ann Intern Med, February 20, 2001; 134(4): 315 - 329. [Abstract] [Full Text] [PDF]

				M. Epstein and G. Bakris Newer Approaches to Antihypertensive Therapy: Use of Fixed-Dose Combination Therapy Arch Intern Med, September 23, 1996; 156(17): 1969 - 1978. [Abstract] [PDF]

				R. J. Sjoberg, K. J. Simcic, and G. S. Kidd The Clonidine Suppression Test for Pheochromocytoma: A Review of Its Utility and Pitfalls Arch Intern Med, June 1, 1992; 152(6): 1193 - 1197. [Abstract] [PDF]

				W. J. Elliott, M. B. Murphy, F. H. Straus II, and J. Jarabak Improved Safety of Glucagon Testing for Pheochromocytoma by Prior {alpha}-Receptor Blockade: A Controlled Trial in a Patient With a Mixed Ganglioneuroma/Pheochromocytoma Arch Intern Med, January 1, 1989; 149(1): 214 - 216. [Abstract] [PDF]