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The uptake of thiopental by body tissues and its relation to the duration of narcosis
Author(s) -
Price H. L.,
Kovnat P. J.,
Safer J. N.,
Conner E. H.,
Price M. L.
Publication year - 1960
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1002/cpt19601116
Subject(s) - anesthesia , limiting , central nervous system , chemistry , anesthetic , nervous system , thiopental sodium , medicine , pharmacology , endocrinology , propofol , mechanical engineering , psychiatry , engineering
A mathematical analysis of the factors affecting thiopental redistribution in the human body after a single intravenous injection of the drug has been devised and presented. Concentration ratios of thiopental predicted mathematically were compared with those obtained by the direct measurement of concentrations in human blood and fat. Real and theoretical results agreed closely. According to the mathematical analysis, and also according to measurements made in man, the central nervous system attained a peak concentration of thiopental slightly less than 1 minute after intravenous injection of the drug. Five minutes later only half this concentration was present, and 10 to 20 minutes after this, only one tenth remained. The rate at which fat concentrated thiopental was too slow to explain the rate at which the central nervous system was depleted. Instead, the lean body tissues rapidly took up most of the thiopental which the brain lost. The lean tissues thus appeared primarily responsible for depleting the central nervous system of the anesthetic. These findings suggest that fat plays a smaller role in limiting the duration of thiopental narcosis than has been supposed; conversely, the mass of the body and the rate at which its tissues are perfused with blood appear more important than has been recognized.