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. 1983 Jun;15(6):719–725. doi: 10.1111/j.1365-2125.1983.tb01556.x

Doxazosin, an alpha 1-adrenoceptor antagonist: pharmacokinetics and concentration-effect relationships in man.

J Vincent, H L Elliott, P A Meredith, J L Reid
PMCID: PMC1427926  PMID: 6135439

Abstract

The effects of single doses of doxazosin, a quinazoline derivative similar to prazosin, were studied in six normotensive volunteers. Both 1 mg (i.v.) or 2 mg (oral) doxazosin caused a fall in blood pressure which was most apparent in the erect posture at 5-6 h following drug administration. The maximum fall in blood pressure following i.v. doxazosin was from 123/81 to 106/69 mm Hg associated with a rise in heart rate from 81 to 107 beats/min. The terminal elimination half-life following oral and intravenous doxazosin was about 9 h. Pressor responsiveness to the alpha 1-adrenoceptor agonist, phenylephrine, showed no significant difference between oral and i.v. doxazosin suggesting that the route of administration did not influence alpha 1-adrenoceptor antagonism at the doses used. Using a pharmacodynamic modelling technique in individual subjects, there was a significant correlation between the change in doxazosin concentration in the effect compartment and its hypotensive effect. With the modelling technique it was possible to show a significant correlation between the pressor responsiveness to the alpha 1-adrenoceptor agonist phenylephrine and the concentration of doxazosin in the effect compartment. This is consistent with the concept that the hypotensive effect of doxazosin is mediated by alpha 1-adrenoceptor blockade.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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