Skip to main content
PMC home page
British Journal of Clinical Pharmacology logoLink to British Journal of Clinical Pharmacology
. 1978 Jun;5(6):507–513. doi: 10.1111/j.1365-2125.1978.tb01665.x

Circulatory and alpha-adrenoceptor blocking effects of phentolamine.

D A Richards, E P Woodings, B N Prichard
PMCID: PMC1429377  PMID: 26372

Abstract

1 Intravenously administered phentolamine provoked immediate decreases in diastolic blood pressure but increases in heart rate and cardiac output. 2 These immediate circulatory effects had largely disappeared twenty minutes after administration and at this time phentolamine did not inhibit increases in blood pressure which were provoked during hand immersion in ice-cold water. 3 Log dose-response curves of noradrenaline induced increases in systolic and diastolic pressure 20 min after intravenous phentolamine were shifted to the right in a parallel manner compared with the curves before phentolamine administration. 4 It was concluded that the immediate and short acting effects induced by phentolamine are due to a non-specific vasodilator effect but in addition phentolamine causes a longer acting alpha-adrenoceptor blockade at vascular adrenoceptor sites. However, by producing both pre- and post-synaptic alpha-adrenoceptor blockade this may explain why this drug exerts only a weak antihypertensive effect.

Full text

PDF
512

Selected References

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

  1. Blakeley A. G., Summers R. J. The effects of labetalol (AH 5158) on adrenergic transmission in the cat spleen. Br J Pharmacol. 1977 Apr;59(4):643–650. doi: 10.1111/j.1476-5381.1977.tb07733.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Cuddy R. P., Smulyan H., Keighley J. F., Markason C. R., Eich R. H. Hemodynamic and catecholamine changes during a standard cold pressor test. Am Heart J. 1966 Apr;71(4):446–454. doi: 10.1016/0002-8703(66)90209-2. [DOI] [PubMed] [Google Scholar]
  3. Doxey J. C., Smith C. F., Walker J. M. Selectivity of blocking agents for pre-and postsynaptic alpha-adrenoceptors. Br J Pharmacol. 1977 May;60(1):91–96. doi: 10.1111/j.1476-5381.1977.tb16752.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Johnson B. F., LaBrooy J., Munro-Faure A. D. Comparative anti-hypertensive effects of labetalol and the combination of oxprenolol and phentolamine. Br J Clin Pharmacol. 1976 Aug;3(4 Suppl 3):783–787. [PubMed] [Google Scholar]
  5. MOYER J. H., CAPLOVITZ C. The clinical results of oral and parenteral administration of 2-(N'p-tolyl-N'-m-hydroxyphenylaminomethyl) imidazoline hydrochloride (regitine) in the treatment of hypertension and an evaluation of the cerebral hemodynamic effects. Am Heart J. 1953 Apr;45(4):602–610. doi: 10.1016/0002-8703(53)90170-7. [DOI] [PubMed] [Google Scholar]
  6. Majid P. A., Meeran M. K., Benaim M. E., Sharma B., Taylor S. H. Alpha- and beta-adrenergic receptor blockade in the treatment of hypertension. Br Heart J. 1974 Jun;36(6):588–596. doi: 10.1136/hrt.36.6.588. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. ROSE G. A., HOLLAND W. W., CROWLEY E. A. A SPHYGMOMANOMETER FOR EPIDEMIOLOGISTS. Lancet. 1964 Feb 8;1(7328):296–300. doi: 10.1016/s0140-6736(64)92408-0. [DOI] [PubMed] [Google Scholar]
  8. Richards D. A., Tuckman J., Prichard B. N. Assessment of alpha- and beta-adrenoceptor blocking actions of labetalol. Br J Clin Pharmacol. 1976 Oct;3(5):849–855. doi: 10.1111/j.1365-2125.1976.tb00637.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. TAYLOR S. H., SUTHERLAND G. R., MACKENZIE G. J., STAUNTON H. P., DONALD K. W. THE CIRCULATORY EFFECTS OF INTRAVENOUS PHENTOLAMINE IN MAN. Circulation. 1965 May;31:741–754. doi: 10.1161/01.cir.31.5.741. [DOI] [PubMed] [Google Scholar]
  10. TAYLOR S. H., SUTHERLAND G. R., MACKENZIE G. J., STAUNTON H. P., DONALD K. W. THE CIRCULATORY EFFECTS OF PHENTOLAMINE IN MAN WITH PARTICULAR RESPECT TO CHANGES IN FOREARM BLOOD FLOW. Clin Sci. 1965 Apr;28:265–284. [PubMed] [Google Scholar]
  11. Taylor S. H., Mackenzie G. J., George M., McDonald A. Effects of adrenergic blockade on the pulmonary circulation in man. Br Heart J. 1965 Sep;27(5):627–639. doi: 10.1136/hrt.27.5.627. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Winchester J. F., Ward D. M., McKillop J. H., Kennedy A. C. Hydrallazine or phentolamine as adjuncts to beta-adrenoceptor blockade/thiazide therapy in hypertension. Br J Clin Pharmacol. 1976 Oct;3(5):863–867. doi: 10.1111/j.1365-2125.1976.tb00639.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Wolf S., Hardy J. D. STUDIES ON PAIN. OBSERVATIONS ON PAIN DUE TO LOCAL COOLING AND ON FACTORS INVOLVED IN THE "COLD PRESSOR" EFFECT. J Clin Invest. 1941 Sep;20(5):521–533. doi: 10.1172/JCI101245. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from British Journal of Clinical Pharmacology are provided here courtesy of British Pharmacological Society

RESOURCES