Table of Contents
ISRN Cardiology
Volume 2014, Article ID 212045, 5 pages
Research Article

Doxapram Hydrochloride Aggravates Adrenaline-Induced Arrhythmias Accompanied by Bidirectional Ventricular Tachycardia

1Division of Clinical Pathophysiology, Graduate School of Health Sciences, Fujita Health University, 1-98 Dengakugakubo Kutsukake, Toyoake, Japan
2Division of Pharmacology, Graduate School of Health Sciences, Fujita Health University, Japan

Received 11 November 2013; Accepted 14 December 2013; Published 9 January 2014

Academic Editors: W. Bloch, G.-N. Tseng, and Z.-M. Zhang

Copyright © 2014 Shota Oikawa et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Objectives. Doxapram hydrochloride is a respiratory stimulant that has an inhibitory effect on myocardial IK1 potassium channels and is thought to increase membrane instability and excitability in myocardial cells. We examined the arrhythmogenic effects of doxapram hydrochloride in a rat model of halothane adrenaline-induced arrhythmia. Methods. Thirteen female Wistar rats (12–14 weeks old) were used in the study. Animals were anesthetized with inhalation of halothane to permit observation of the effects of doxapram hydrochloride on halothane adrenaline-induced arrhythmia. Time-dependent changes in ECG repolarization characteristics (QT, QTc, JTp, JT, and Tp-e intervals) were studied. Results. Doxapram hydrochloride itself did not induce arrhythmia but did induce bidirectional ventricular tachycardia after addition of adrenaline. Conclusion. Drug-induced impairment of intracellular Ca2+ regulation caused BVT in the absence of genetic abnormalities in proteins in the sarcoplasmic reticulum.