[Plasma levobupivacaine concentrations following epidural administration of levobupivacaine conjugated with or without maltosyl-beta-cyclodextrin].
BACKGROUND
To investigate the pharmacokinetics of complexation of levobupivacaine with maltosyl-beta-cyclodextrin, the plasma concentrations of levobupivacaine were measured following epidural administration of levobupivacaine conjugated with maltosyl-beta-cyclodextrin or levobupivacaine alone in a rabbit model.


METHODS
Rabbits were randomly divided into two groups, levobupivacaine (1%) group (n = 6) and levobupivacaine (1%) conjugated with maltosyl-beta-cyclodextrin (100 mM) group (n = 6). One ml of each solution was randomly injected through an epidural catheter placed at L5-6. The plasma levobupivacaine concentrations were measured before and 5, 10, 15, 30, 60, 120, 240, 360, and 480 min after injection.


RESULTS
The plasma levobupivacaine concentrations were significantly higher in the levobupivacaine conjugated with maltosyl-beta-cyclodextrin group than in levobupivacaine group at 5 min (1,465 +/- 311, 1,033 +/- 347 ng x ml(-1)), 10 min (1,068 +/- 237, 731 +/- 191), and 15 min (958 +/- 311, 605 +/- 118). There were no differences in area under the curve (1,551 +/- 387, 1,176 +/- 154 ng x hr x ml(-1)) and elimination half life (100 +/- 54, 78 +/- 37 min) between the two groups.


CONCLUSIONS
The results of this study indicated that the absorption of levobupivacaine conjugated with maltosyl-beta-cyclodextrin from the epidural space and the elimination from the blood were similar to plain levobupivacaine.
Karashima
Ken
K
Department of Pathophysiological Diagnosis and Therapy, Anesthesiology and Intensive Care, Faculty of Medicine, University of Miyazaki, Miyazaki 889-1692.
Kasaba
Toshiharu
T
Taniguchi
Masahiko
M
Irikura
Mitsuru
M
Irie
Tetsumi
T
Takasaki
Mayumi
M
D000767:Anesthesia, Epidural; D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D000818:Animals; D002045:Bupivacaine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood / Q000493:pharmacokinetics; D003505:Cyclodextrins / Q000008:administration & dosage*; D000077554:Levobupivacaine; D008297:Male; D008320:Maltose / Q000008:administration & dosage / Q000031:analogs & derivatives*; D011817:Rabbits; D011897:Random Allocation
D000779:Anesthetics, Local; D003505:Cyclodextrins; C433303:maltosyl-cyclodextrin; D008320:Maltose; D000077554:Levobupivacaine; D002045:Bupivacaine