DOUBLE-BLIND CROSSOVER COMPARISON OF TEGRETOL-XR AND TEGRETOL IN PATIENTS WITH EPILEPSY

This multicenter, double-blind, crossover study compared Tegretol-XR a nd Tegretol tablets with respect to trough plasma carbamazepine (CBZ) concentrations, seizure control, tolerability, and safety. We randomiz ed 96 patients with epilepsy to 56-day monotherapy with their usual da ily CBZ dose administered as (1) Tegretol-XR 200-mg tablets every 12 h ours plus placebo or (2) Tegretol 200-mg tablets three or four times d aily plus placebo. Upon completion, patients immediately switched to t he alternate treatment for 56 days. During the study, 98% of patients had plasma CBZ concentrations within the recommended therapeutic range during Tegretol-XR treatment and 97% did during Tegretol treatment. T he seizure rate during treatment, compared with the baseline seizure r ate, decreased in 26% of patients both during treatment with Tegretol- XR and during treatment with Tegretol, and it remained the same in 48% of patients during Tegretol-XR therapy and in 52% of patients during Tegretol therapy. We did not observe any pattern of change in seizure frequency. We switched patients on a milligram-per-milligram basis fro m multiple-daily-dose Tegretol. to Tegretol-XR twice daily from one da y to the next without retitrating the daily dose.