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 Larochelle, P. Articles by Armstrong, J. Search for Related Content PubMed PubMed Citation Articles by Larochelle, P. Articles by Armstrong, J.

Hypertension, Vol 4, 93-101, Copyright © 1982 by American Heart Association

ARTICLES

Prazosin plasma concentration and blood pressure reduction

P Larochelle, P du Souich, P Hamet, P Larocque and J Armstrong

Prazosin was administered to 16 patients with essential hypertension in an initial dose of 0.5 mg, after which the blood pressure (BP), pulse, and plasma concentrations of prazosin were measured at 0, 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, and 24 hours. The dose of prazosin was then increased over 16 to 20 weeks, and similar sequences of measurements were obtained twice. Eleven patients completed the 20-week course. All patients did not respond in a similar way; two distinct patterns of BP and pulse response emerged, although there was no significant difference in the pharmacokinetic parameters, namely, absorption rate constant (Ka), maximum plasma concentration (Cpmax), time to reach the maximum concentration (Tmax), prazosin plasma half-life (T 1/2), elimination rate constant (kel), prazosin plasma concentration-time curve (AUC), and clearance. Patients in Group 1 had a marked reduction (52/30 mm Hg) of BP after the first dose of prazosin, no pulse increase, and needed a small dose of prazosin to maintain an adequate BP response. Patients in Group 3 had a minimal reduction in BP (14/13 mm Hg) after a first dose, a significant pulse increase, and needed a high dose of prazosin to control their BP. We conclude that this effect might be due to a different drug-receptor interaction, and the BP response and dose could be predicted from the response of the first dose of prazosin.

This article has been cited by other articles:

				A. F. Khoury and N. M. Kaplan {alpha}-Blocker Therapy of Hypertension: An Unfulfilled Promise JAMA, July 17, 1991; 266(3): 394 - 398. [Abstract] [PDF]