Pharmacokinetics of thiocolchicoside in humans using a specific radioimmunoassay.
The myorelaxant thiocolchicoside (TC), an analogue of colchicine (COL), was assayed in plasma and urine by a radioimmunoassay (RIA) using a cross-reacting COL-specific polyclonal antibody. Cross-reactivity was 56% for TC, giving a limit of quantification of 0.5 ng/ml and a linear response from 0.5 to 100 ng/ml. Specificity was checked by cross-reactivity studies with COL analogues and by using liquid chromatography and RIA in tandem on urine samples. Two immunoreactive peaks were detected, but the nonspecific peak represented < 2% of the total urine concentration of TC. Pharmacokinetics of TC following infusion of 4 mg in two subjects revealed a moderate distribution (Vss from 31 to 35 L) and mainly extrarenal elimination (75% of the total body clearance). Terminal half-lives ranged from 2.4 to 2.7 h in plasma and from 3.2 to 3.7 h in urine.
Sandouk
P
P
INSERM U.26, Hôpital F. Widal, Paris, France.
Chappey
O
O
d'Yvoire
M B
MB
Scherrmann
J M
JM
D000328:Adult; D000368:Aged; D000906:Antibodies; D002851:Chromatography, High Pressure Liquid; D003078:Colchicine / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics / Q000652:urine; D003198:Computer Simulation; D003429:Cross Reactions; D006207:Half-Life; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D011863:Radioimmunoassay; D015203:Reproducibility of Results
D000906:Antibodies; D003078:Colchicine; C004280:thiocolchicoside