RELATIONSHIP OF CARBAMAZEPINE REDUCTION RATE TO SEIZURE FREQUENCY DURING INPATIENT TELEMETRY

To establish guidelines for medication reduction during inpatient telemetry, the records of 18 children and young adults with refractory partial seizures undergoing carbamazepine (CBZ) reductions during continuous video/EEG telemetry were reviewed. Six patients were receiving CBZ monotherapy, and 12 patients were treated with an additional antiepileptic drug (AED) maintained at baseline dosage during CBZ taper. Despite relatively rapid mean reductions in dosage of 44% by day 2 of taper, no patients experienced frequent repetitive seizures or status epilepticus (SE). Seizure rate during the entire CBZ reduction period correlated significantly with rate of drug reduction. Linear regression analysis showed drug reduction rate to be a good predictor of seizure rate. Fourteen patients experienced at least three seizures during CBZ taper. On the average, the third seizure occurred on day 5 of taper at a percentage of dose reduction of 79%. In 8 patients, CBZ concentrations were measured both before taper and less than or equal to 24 h after the third seizure. For these patients, seizure rate also correlated significantly with reduction in CBZ level. We conclude that manipulation of CBZ dose reduction rate is important in maximizing seizure frequency during telemetry and, in our patients, a relatively rapid rate of dose reduction was safe and effective in promoting seizure recordings.