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August 1987

Carbamazepine Plasma Concentration: Relationship to Cognitive Impairment

Arch Neurol. 1987;44(8):863-867. doi:10.1001/archneur.1987.00520200065021

• Neuropsychological function was assessed before and after carbamazepine monotherapy in children with newly diagnosed complex partial epilepsy. Simultaneous video-electroencephalographic monitoring examined the influence of subclinical abnormal electrical discharges on performance. Total and unbound plasma carbamazepine concentrations were examined in relation to changes in performance at low (carbamazepine level, ≤32 μmol/L [≤7.5 mg/L]) and moderate (carbamazepine level, >34 μmol/L [>8.0 mg/L]) drug levels. The data suggest a mild beneficial effect of carbamazepine on speeded eye-hand coordination and, at low drug levels, more rapid processing of items in memory. Efficiency of learning new information and memory-scanning rate displayed a concentration-dependent relationship with carbamazepine level, with poor performance significantly associated with higher carbamazepine plasma concentrations. Carbamazepine free levels were equivalent to total levels in predicting cognitive side effects.