Cardiovascular effects of and interaction between calcium blocking drugs and anesthetics in chronically instrumented dogs: VII. Verapamil and thiopental

D. C. Hill, P. F. Wouters, J. E. Chelly, M. F. Doursout, D. R. Abernethy, C. J. Hartley, R. G. Merin

Research output: Contribution to journalArticlepeer-review

Abstract

To assess the role of basal anesthesia in the negative inotropic properties of verapamil, the effect of thiopental (30 mg/kg followed by 3.5 mg · kg-1 · min-1) on verapamil pharmacokinetics (200 μg/kg iv; n = 6) and its pharmacodynamics (3 and 6 μg · kg-1 · min-1; n = 11) in chronically instrumented dogs was studied. In the presence of thiopental, verapamil pharmacokinetics remained essentially unchanges. In contrast, anesthesia altered verapamil hemodynamic properties. In the conscious animal verapamil infusions increased heart rate (14 ± 3 and 27 ± 4 beats/min, respectively), cardiac output (0.22 ± 0.07 and 0.24 ± 0.08, l/min, respectively) and PR interval (14 ± 2 and 25 ± 6 ms, respectively) and slightly decreased dP/dt (-315 ± 114 and -419 ± 106 mmHg/s, respectively). Systemic vascular resistance (SVR) decreased at the low dose (-2.7 ± 0.7 mmHg · 1 · min-1), and stroke volume decreased at the high dose (-4.4 ± 0.6 ml). Yet the presence of thiopental resulted in an accentuation of verapamil-induced tachycardia (27 ± 7 and 31 ± 6 beats/min, respectively), and a decrease in stroke volume (-5.3 ± 2.0 and -6.3 ± 2.1 ml, respectively). At 3 μg · kg-1 · min-1 verapamil did not increase PR interval, cardiac output, or vasodilation. Finally, at 6 μg · kg-1 · min-1 verapamil did not decrease dP/dt and increased renal blood flow (21.8 ± 6.4 ml/min). These data provide evidence that the negative inotropic properties of verapamil are more pronounced in the presence of thiopental. However, the role of basal anesthesia appears to be limited.

Original languageEnglish (US)
Pages (from-to)586-590
Number of pages5
JournalAnesthesiology
Volume71
Issue number4
DOIs
StatePublished - Jan 1 1989

ASJC Scopus subject areas

  • Anesthesiology and Pain Medicine

Fingerprint

Dive into the research topics of 'Cardiovascular effects of and interaction between calcium blocking drugs and anesthetics in chronically instrumented dogs: VII. Verapamil and thiopental'. Together they form a unique fingerprint.

Cite this