Study of the sensitivity of neonates to digoxin: contribution of erythrocyte /sup 86/Rb uptake test

Journal Article · Thu Jan 01 04:00:00 EST 1981 · Pediatr. Pharmacol.; (United States)

OSTI ID:6765778

Zannad, F; Marchal, F; Royer, R J; Vert, P; Robert, J

In general, there is little agreement how digoxin should be used in newborn, and the results of studies in this field seem contradictory. This study attempts a quantitative assessment of the number and the sensitivity of cellular receptors for digoxin in the organism, by the in vitro measurement of erythrocyte /sup 86/Rb neonates compared with adults and old people. Red blood cells are first incubated with differing concentrations of digoxin, and then incubated with /sup 86/Rb. The initial level of /sup 86/Rb uptake (Rbi) is that observed in the absence of digoxin. The 50% index of captation (IC50) is the digoxin concentration in nanograms per ml at which /sup 86/Rb uptake is half Rbi. Three grups of patients were studied: Group I: 12 neonates, less that 5 days old; Group II: 11 adults (26 to 57 years old); Group III: 9 elderly people (71 to 82 years old). Rbi was significantly lower in neonates (Mean +/- SD: 25.8% +/- 3.5, P less than 0.001) and in the elderly (29.9% +/- 3.1) than in adults (36.8% +/- 4.6). IC50 was significantly lower in the elderly (12.1 mg/ml +/- 2.4) than in the adult patients (20.5 ng/ml +/- 5.5, P less than 0.001). In the newborns, values of IC50 were widely scattered (16.2 ng/ml +/- 7.2). The authors suggest that since Rbi reflects Na+, K+-ATPase activity, this activity is diminished in newborn and old people, and indicates that they have fewer cellular recaptors for digoxin than adults. In the elderly, the low IC50 would imply increased sensitivity to digoxin. In neonates, the wide range of values for IC50 suggests considerable individual variation in sensitivity to digoxin. The results aer consistent with the recently recomnended lower dosages of digoxin i neonates.

• Research Organization: Laboratoire de Pharmacologie B., Faculte de Medecine, Nancy, France
• OSTI ID: 6765778
• Journal Information: Pediatr. Pharmacol.; (United States), Journal Name: Pediatr. Pharmacol.; (United States) Vol. 1:3; ISSN PPHAD
• Country of Publication: United States
• Language: English

Related Subjects

550201 -- Biochemistry-- Tracer Techniques
550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
AGE DEPENDENCE
ALKALI METAL ISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CARBOHYDRATES
CARDIAC GLYCOSIDES
CARDIOTONICS
CARDIOVASCULAR AGENTS
COMPARATIVE EVALUATIONS
DAYS LIVING RADIOISOTOPES
DIGITALIS GLYCOSIDES
DIGOXIN
DOSE-RESPONSE RELATIONSHIPS
DRUGS
ERYTHROCYTES
GLYCOSIDES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MATERIALS
MINUTES LIVING RADIOISOTOPES
NEONATES
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PHARMACOLOGY
RADIOISOTOPES
RECEPTORS
RUBIDIUM 86
RUBIDIUM ISOTOPES
TRACER TECHNIQUES
UPTAKE