Biomaterial Database

EEG quantitation of narcotic effect: the comparative pharmacodynamics of fentanyl and alfentanil. 1985

J C Scott, and K V Ponganis, and D R Stanski

Fentanyl and alfentanil produce very similar electroencephalographic (EEG) changes in humans. With increasing serum concentrations of either narcotic, progressive slowing in frequency occurs. This narcotic effect on the brain was quantitated using off-line EEG power spectrum analysis. During EEG recording, six unpremedicated patients received a fentanyl infusion (150 micrograms/min), and six received alfentanil (1,500 micrograms/min) until a specific level of EEG depression (delta waves) occurred. Timed arterial blood samples were obtained for measurement of the narcotic serum concentrations. The narcotic-induced EEG changes were found to lag behind (in time) the serum narcotic concentration changes. To accurately relate EEG changes to serum narcotic concentrations, a pharmacodynamic model (inhibitory sigmoid Emax) was combined with a pharmacokinetic model that incorporated an "effect" compartment. (The effect compartment is the separate pharmacokinetic compartment where drug effect is directly proportional to drug concentration. It is the effect site.) The magnitude of the time lag was quantitated by the half-time of equilibration between serum narcotic concentrations and concentrations in the effect compartment. With fentanyl a significantly greater time lag was present (half-time = 6.4 +/- 1.3 min; mean +/- SD) than with alfentanil (half-time = 1.1 +/- 0.3 min). This difference in time lag between blood concentration and effect may be due to the larger brain-blood partition coefficient for fentanyl. The steady-state serum concentration that caused one-half of the maximal EEG slowing was 6.9 +/- 1.5 ng/ml for fentanyl, compared with 520 +/- 163 ng/ml for alfentanil.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D012119	Respiration	The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (	Breathing
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D003201	Computers	Programmable electronic devices designed to accept data, perform prescribed mathematical and logical operations at high speed, and display the results of these operations.	Calculators, Programmable,Computer Hardware,Computers, Digital,Hardware, Computer,Calculator, Programmable,Computer,Computer, Digital,Digital Computer,Digital Computers,Programmable Calculator,Programmable Calculators
D004569	Electroencephalography	Recording of electric currents developed in the brain by means of electrodes applied to the scalp, to the surface of the brain, or placed within the substance of the brain.	EEG,Electroencephalogram,Electroencephalograms
D005283	Fentanyl	A potent narcotic analgesic, abuse of which leads to habituation or addiction. It is primarily a mu-opioid agonist. Fentanyl is also used as an adjunct to general anesthetics, and as an anesthetic for induction and maintenance. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1078)	Phentanyl,Duragesic,Durogesic,Fentanest,Fentanyl Citrate,Fentora,R-4263,Sublimaze,Transmucosal Oral Fentanyl Citrate,R 4263,R4263
D005583	Fourier Analysis	Analysis based on the mathematical function first formulated by Jean-Baptiste-Joseph Fourier in 1807. The function, known as the Fourier transform, describes the sinusoidal pattern of any fluctuating pattern in the physical world in terms of its amplitude and its phase. It has broad applications in biomedicine, e.g., analysis of the x-ray crystallography data pivotal in identifying the double helical nature of DNA and in analysis of other molecules, including viruses, and the modified back-projection algorithm universally used in computerized tomography imaging, etc. (From Segen, The Dictionary of Modern Medicine, 1992)	Fourier Series,Fourier Transform,Analysis, Cyclic,Analysis, Fourier,Cyclic Analysis,Analyses, Cyclic,Cyclic Analyses,Series, Fourier,Transform, Fourier
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man