Use of stable labelled carbamazepine to study its kinetics during chronic carbamazepine treatment.
The kinetics of carbamazepine using stable labelled 15N-carbamazepine was studied in 4 epileptic patients who had been treated with it for at least 6 months. There was a decrease in half-life (12.3 +/- 0.8 h) and an increase in total plasma clearance (58.0 +/- 6.5 ml/min) as compared to single dose studies, which provide further evidence that carbamazepine induces its own metabolism during long-term treatment. Analysis of the urinary metabolites indicated induction of the epoxide-trans-diol pathway. Predicted and observed steady-state plasma levels were in good agreement, thus demonstrating that the use of stable labelled drugs is a useful technique to elucidate changes in kinetics and metabolism which may occur in patients during long-term treatment.
D000284:Administration, Oral; D000328:Adult; D002220:Carbamazepine / Q000008:administration & dosage / Q000378:metabolism*; D004833:Epilepsy, Temporal Lobe / Q000188:drug therapy / Q000378:metabolism*; D004830:Epilepsy, Tonic-Clonic / Q000188:drug therapy / Q000378:metabolism*; D005260:Female; D006207:Half-Life; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D009587:Nitrogen Isotopes
D009587:Nitrogen Isotopes; D002220:Carbamazepine