Carbamazepine: a clinical biopharmaceutical study.
In a biopharmaceutical study of carbamazepine, the F-CBZ, DAK preparation, which contained small particles with minor variation in size, had a more rapid dissolution rate than Tegretol, which contained larger particles of more variable size. Accordingly, carbamazepine had a more rapid absorption rate from F-CBZ, DAK than from Tegretol in a comparative absorption test involving single-dose administration of 200 mg to 8 healthy volunteers. The clinical significance of the difference in absorption rates for the steady state levels of carbamazepine and carbamazepine-10,11-epoxide, and the frequency of side-effects in relation to tablet intake, were evaluated in a double-blind, randomized, double-dummy cross-over trial of 35 days' duration, in 21 well-adjusted epileptic patients. 9 patients were treated with Tegretol alone and 12 with Tegretol combined with other antiepileptic drugs. A lower steady state plasma level of carbamazepine was found at 08.00 h during treatment with F-CBZ, DAK in comparison with Tegretol. The difference was small. There was no difference in the type and frequency of side-effects or seizures between the 2 preparations. The frequency of epileptic fits was not correlated with the plasma level of carbamazepine or the epoxide. Side-effects, however, had a tendency to be correlated with the concentration of the epoxide. Thus, the particle size influenced the absorption rate of carbamazepine, without having a significant correlation wih the frequency of side-effects. The difference in the minimum plasma level of carbamazepine between treatments with the two preparations was modest, and appeared to be without clinical significance.
D000328:Adult; D002220:Carbamazepine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives / Q000378:metabolism*; D005260:Female; D006801:Humans; D007408:Intestinal Absorption; D008297:Male; D010316:Particle Size; D012995:Solubility
D002220:Carbamazepine; C012227:carbamazepine epoxide