Effects of tiagabine monotherapy on abilities, adjustment, and mood

Purpose: We evaluated the dose-related impacts of tiagabine (TGB) on cognition and mood in a monotherapy study. Methods: Patients were 123 adults with uncontrolled partial seizures, each treated with a single currently available antiepileptic drug (AED) for management of clinical epilepsy. They completed a battery of neuropsychological tests during an 8-week prospective baseline period and once again at the end of the 12-week fixed-dose period (or earlier if they dropped out of the study). Sixty-six patients were randomized to 6 mg/day TGB and 57 were randomized to 36 mg/day TGB. Results: Few changes in either abilities or adjustment and mood were noted when all patients were considered as a single group. However, analysis of both dose and attainment of TGB monotherapy showed that patients receiving TGB monotherapy did best, improving particularly in the areas of adjustment and mood with low-dose TGB and in the area of abilities with high-dose TGB. Patients who did not attain monotherapy showed no change except that the high-dose group did not perform as well on measures of mood and adjustment. Baseline AED and changes in seizure control did not affect the results. Conclusions: Patients' attainment of TGB monotherapy was associated with their achievement of positive changes of varying degree on psychological tests. Failure to attain TGB monotherapy was associated with no changes on the tests except in patients receiving high-dose TGB where it appeared that some alterations in mood might have been avoided if a slower titration schedule had been used.