Clobazam kinetics: intrasubject variability and effect of food on adsorption

The kinetics of single 20-mg oral doses of clobazam was determined on two occasions in 12 healthy male volunteers. Clobazam was given in the fasting state on one occasion and following a standard breakfast on another. Compared with the fasting state, administration of clobazam with food reduced mean peak plasma concentrations (465 vs. 333 ng/ml, P less than 0.01), and prolonged the time to reach peak concentration (1.7 vs. 2.5 hours after dosage, P less than 0.1). Total area under the curve nor the extent of formation of desmethylclobazam, the major metabolite. Clobazam AUC and elimination half-life each were highly correlated within subjects between the two trials (r = 0.97 and 0.95, respectively). Thus, administration of clobazam with food slows the rate of clobazam absorption but does not alter the completeness of absorption. The rate of drug elimination is highly replicable upon repeated administration clobazam to the same individual.