We sequentially determined carbamazepine clearance values in 17 patients at the end of weeks 1, 2, 4, 8, and 12 of monotherapy. There were no significant differences among these clearance values. In 11 of 17 patients, week 1 clearance accurately predicted week 12 Hume carbamazepine serum concentration (within ±33%). Our data indicate that carbamazepine autoinduction was completed within the first 1 or 2 weeks of monotherapy. Serum concentration values obtained after 1 week of monotherapy, using our dosing regimen, can be used to predict directly the dosing rate needed to obtain a specific serum concentration in most patients. © 1989 American Academy of Neurology.