Abstract
The effect of indoramin, a selective alpha 1-adrenoceptor antagonist, on ECG time intervals in normal man was studied. Significant prolongation of QTc was observed after indoramin 100 mg, with no change in QRS duration. In addition, the slope of the RR/QT relationship was changed by indoramin 100 mg. These results suggest that indoramin may have Class III antiarrhythmic activity. If such activity were to affect the SA node, it may explain at least in part the observed lack of reflex tachycardia after indoramin administration.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Algate D. R., Waterfall J. F. Action of indoramin on pre- and postsynaptic alpha-adrenoceptors in pithed rats. J Pharm Pharmacol. 1978 Oct;30(10):651–652. doi: 10.1111/j.2042-7158.1978.tb13351.x. [DOI] [PubMed] [Google Scholar]
- Alps B. J., Borrows E. T., Johnson E. S., Staniforth M. W., Wilson A. B. A comparison of the cardiovascular actions of indoramin, propranolol, lignocaine, and quinidine. Cardiovasc Res. 1972 May;6(3):226–234. doi: 10.1093/cvr/6.3.226. [DOI] [PubMed] [Google Scholar]
- Alps B. J., Hill M., Fidler K., Johnson E. S., Wilson A. B. The reversal of experimental cardiac arrhythmias by indoramin (Wy 21901). J Pharm Pharmacol. 1971 Sep;23(9):678–686. doi: 10.1111/j.2042-7158.1971.tb08744.x. [DOI] [PubMed] [Google Scholar]
- Baum T., Shropshire A. T., Eckfeld D. K., Metz N., Dinish J. L., Peters J. R., Butz F., Gluckman M. I. Studies relating to the antihypertensive and antidysrhythmic action of indoramin. Arch Int Pharmacodyn Ther. 1973 Aug;204(2):390–406. [PubMed] [Google Scholar]
- Bexton R. S., Camm A. J. Drugs with a class III antiarrhythmic action. Pharmacol Ther. 1982;17(3):315–355. doi: 10.1016/0163-7258(82)90020-1. [DOI] [PubMed] [Google Scholar]
- Harron D. W., Kerr M. J., Shanks R. G. Investigation into mechanism of lack of reflex tachycardia in response to hypotensive action of indoramin in dogs. J Cardiovasc Pharmacol. 1984 Jul-Aug;6(4):596–600. doi: 10.1097/00005344-198407000-00007. [DOI] [PubMed] [Google Scholar]
- Heissenbuttel R. H., Bigger J. T., Jr The effect of oral quinidine on intraventricular conduction in man: correlation of plasma quinidine with changes in QRS duration. Am Heart J. 1970 Oct;80(4):453–462. doi: 10.1016/0002-8703(70)90191-2. [DOI] [PubMed] [Google Scholar]
- Kelman A. W., Whiting B., Summer D. J. Correction equation for ECG time intervals. Br J Clin Pharmacol. 1984 Jul;18(1):113–115. doi: 10.1111/j.1365-2125.1984.tb05036.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Millar J. S., Vaughan Williams E. M. Pharmacological mapping of regional effects in the rabbit heart of some new antiarrhythmic drugs. Br J Pharmacol. 1983 Jul;79(3):701–709. doi: 10.1111/j.1476-5381.1983.tb10007.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nicholls D. P., Harron D. W., Shanks R. G. Cardiovascular effects of indoramin in man--a dose ranging study. Br J Clin Pharmacol. 1983 Jan;15(1):31–36. doi: 10.1111/j.1365-2125.1983.tb01459.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nicholls D. P., O'Connor P. C., Harron D. W., Leahey W. J., Shanks R. G. Differential blockade of alpha-adrenoceptors by indoramin. Br J Clin Pharmacol. 1984 Jun;17(6):719–728. doi: 10.1111/j.1365-2125.1984.tb02409.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rhodes K. F., Waterfall J. F. Pre- and postsynaptic alpha-adrenoceptor antagonism by indoramin in isolated tissues of the rat. J Pharm Pharmacol. 1978 Aug;30(8):516–517. doi: 10.1111/j.2042-7158.1978.tb13308.x. [DOI] [PubMed] [Google Scholar]
- Staniforth D. H. The QT interval and cycle length: the influence of atropine, hyoscine and exercise. Br J Clin Pharmacol. 1983 Dec;16(6):615–621. doi: 10.1111/j.1365-2125.1983.tb02230.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Williams E. M. Electrophysiological basis for a rational approach to antidysrhythmic drug therapy. Adv Drug Res. 1974;9:69–101. [PubMed] [Google Scholar]