Effect of topiramate monotherapy on height in newly diagnosed children with epilepsy

We conducted a post hoc assessment of the effect of ≥6 months of topiramate monotherapy on height in pediatric patients with newly diagnosed partial-onset seizure. Data on height measured nonsystematically up to 4 years from two randomized, double-blind studies and their open-label extensions were combined and converted to z scores and percentiles by patient's sex and age. Height velocity values (centimeters per year) and the associated z scores were computed for each postbaseline year using normative data. Median height velocity (centimeters per year) values and the associated z scores for patients ages 6-9 years were, year 1: 4.7 (-0.91); year 2: 4.2 (-1.62); year 3: 4.5 (-1.87); and for patients ages 10-15 years were, year 1: 4.0 (-0.76); year 2: 2.8 (-1.34); year 3: 3.1 (-0.74). There was a significant correlation between height velocity z score and change from baseline in height z score (r = 0.94 [n = 117]; P < 0.0001). Patient's bicarbonate status (low was defined as two postbaseline serum bicarbonate values <20 mmol/L) and sex had no effect on height velocity. In both age groups, continued growth was observed; however, the growth rate was slower than expected compared with a matched normal population from years 1 to 2 and showed minimal recovery from years 2 to 3.