Relationship between red blood cell potassium and plasma digitoxin concentrations in intoxicated patients.

Abstract

After severe acute self-poisoning by cardiac glycosides, significant and persistent depletion of red blood cell K+ due to inhibition of Na+K+ ATPase is seen. Because of a delay between the time course of plasma digitalis concentrations and that of red blood cell K+ depletion, no direct relation exists between the two, and RBC K+ has hitherto not been considered useful as prognostic indicators of clinical outcome. In an effort to solve this problem, red blood cell K+ was measured by atomic absorption spectrophotometry and plasma digitoxin concentration assayed in six patients admitted to an intensive care unit after digitoxin self-poisoning. Using the effect compartment model of Sheiner, a relationship based on a sigmoid Emax model was able to relate the digitoxin concentration at the action site to red blood cell K+ depletion. Thus the duration of red blood cell K+ depletion could be predicted from two relative simple in vitro assays. Since RBC K+ is a marker of the inhibition of Na+K+ ATPase by digitoxin, this method could be of use for the management of patients self-poisoned with digitalis.

• Authors: M Urtizberea, M Rochdi, A Sabouraud, C Bismuth, J M Scherrmann
• Journal: Pharmacology & toxicology (Pharmacol Toxicol) Vol. 68 Issue 4 Pg. 237-42 (Apr 1991) ISSN: 0901-9928 [Print] Denmark
• PMID: 1866386 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Digitoxin
• Potassium

Topics

• Adult
• Digitoxin (blood, poisoning)
• Erythrocytes (metabolism)
• Female
• Humans
• Male
• Middle Aged
• Poisoning (blood)
• Potassium (blood)
• Suicide, Attempted