[Characterization of propofol binding to plasma proteins and possible interactions].
OBJECTIVE
a) To study the binding of propofol to proteins in plasma samples from healthy volunteers and in solutions of albumin and alpha 1-acid glycoprotein (AGA); b) to describe the nature of the bond and possible interactions with other substances that are potential displacers: salicylate, phenylbutazone, sulfisoxazole, tolbutamide, sodium valproate, sodium oleate and penbutolol; c) to assess the effect of propofol on the binding of specific markers and possible binding sites in the following proteins: 14C-warfarin, 3H-diazepam, 3H-midazolam, 3H-imidazole, 3H-penbutolol and 3H-morphine.


METHODS
The free fraction was obtained in all samples by ultrafiltration and measurement of the free concentration of propofol by liquid chromatography and of the markers by scintillation spectrometry.


RESULTS
The free fraction of propofol in plasma was 0.98 +/- 0.12% and binding was not saturable. Albumin seems to play an important role (95% bound), whereas the participation of AGA was low (54% bound). Propofol did not affect the binding of any of the markers studied. Nor did the presence of other drugs at therapeutic plasma concentrations affect the binding of propofol.


CONCLUSIONS
The binding of propofol to plasma proteins seems unlikely to cause drug interactions in clinical practice.
Departamento de Farmacología, Facultad de Medicina y Odontología, Universidad de País Vasco, Leioa, Vizcaya.
M J
MJ
Garrido
R M
RM
Jiménez
J M
JM
Rodríguez-Sasiaín
C
C
Aguirre
L
L
Aguilera
R
R
Calvo
D001798:Blood Proteins / Q000378:metabolism*; D004347:Drug Interactions; D006801:Humans; D009961:Orosomucoid / Q000378:metabolism; D004364:Pharmaceutical Preparations / Q000378:metabolism; D015742:Propofol / Q000097:blood / Q000493:pharmacokinetics*; D011485:Protein Binding; D012709:Serum Albumin / Q000378:metabolism
D001798:Blood Proteins; D009961:Orosomucoid; D004364:Pharmaceutical Preparations; D012709:Serum Albumin; D015742:Propofol
Caracterización de la fijación de propofol a las proteínas plasmáticas y posibles interacciones.