Tiagabine versus phenytoin and carbamazepine as add-on therapies: effects on abilities, adjustment, and mood

The effects of tiagabine (TGB) on abilities and on adjustment and mood are as yet incompletely understood. These effects were compared with those of p henytoin (PHT) and carbamazepine (CBZ) in an add-on study. Patients include d in the analysis were adults with uncontrolled partial seizures who at stu dy entry were on CBZ alone (n = 153) or on PHT alone (n = 124). Of the pati ents receiving CBZ, 82 were randomized to add-on TGB and 71 were randomized to add-on PHT during the double-blind period. Of the patients receiving PH T, 58 were randomized to add-on TGB and 66 were randomized to add-on CBZ. E ight tests of mental abilities and three of mood and adjustment were given prior to assignment of add-on treatment and after up to 16 weeks of add-on treatment. For the baseline CBZ group, analyses were done to search for dif ferential changes from baseline in the test scores of the add-on TGB and ad d-on PHT groups, and for the baseline PHT group in the add-on TGB and add-o n CBZ groups. In the baseline CBZ group, no differences in test scores were found between PHT and TGB. In the baseline PHT group for the area of abili ties, patients treated with TGB had improved verbal fluency, as well as qui cker responses on a test of perceptual/motor speed compared with patients t reated with CBZ, For the baseline PHT group in the area of adjustment and m ood, patients treated with TGB reported less positive mood and more financi al concerns compared to patients treated with CBZ. Overall, add-on TGB show ed few or no differences in comparison with add-on CBZ and add-on PHT. (C) 2000 Elsevier Science B.V. All rights reserved.