Abstracts

RATIONALE: To determine the effect of zonisamide (ZNS) on weight in adults with epilepsy in a clinical practice. Obesity is a major health issue in the United States (U.S.). For persons with epilepsy, antiepileptic drugs (AEDs) may contribute significantly to to weight. ZNS is a relatively new AED in the U.S. market, and was associated with weight loss in phase III clinical trials.
METHODS: The MINCEP[reg] database, of more than 2,500 people with epilepsy, was searched for treatment with ZNS. Only adults ([gte] 16 years old) who were started on ZNS from 2000 onward were considered for the study (N=103). Seventy-four charts were randomly reviewed for baseline weight (W[sub]0[/sub]), weight while on ZNS (W[sub]ZNS[/sub]), ZNS dosages and blood levels, concomitant AEDs and their blood levels. A total of 29 women (mean age 33 years, range 16-52 years) and 24 men (mean age 36 years, range 16-61 years) had complete data. Length of treatment ranged from 3-24 months, mean 11 months. Student t-test and chi square statistics were used.
RESULTS: Overall mean W[sub]0[/sub] and W[sub]ZNS[/sub] was 76.78 [plusminus] 20.0 kg and 73.76 [plusminus] 20.0 kg (p[lt]0.001). Mean W[sub]0[/sub] and W[sub]ZNS[/sub] for women were 71.7 [plusminus] 21.0 kg (range 44.4 - 136 kg) and 67.8 [plusminus] 18.8 kg (range 40.6 - 134 kg) (p[lt]0.005). Mean W[sub]0[/sub] and W[sub]ZNS[/sub] for men were 82.9 [plusminus] 17.2 kg (range 54.1 - 128.8 kg) and 80.9 [plusminus] 19.4 kg (range 53 - 135.5 kg) (p=0.079). Twenty-three women (79%) and 15 men (62%) had weight loss of 1 kg or more by chi square (ns). Absolute weight difference and percentage of weight loss from baseline were calculated. Weight losses ranged from -1.3 kg to -28.9 kg (mean -5.5 kg) for women and -1.1 kg to -12 kg (mean -5.1 kg) for men in those who had weight loss. The mean percentage of weight loss for women and men were 7.1 [plusminus] 5.5% and 6.56 [plusminus] 4.7% respectively (p=0.76). All 3 patients on ZNS monotherapy had weight loss (mean -4.5 kg). Fifty patients were on ZNS with 2-4 other AEDs. The most commonly used concomitant AEDs were sodium valproate (22), carbamazepine (21), and leviteracetam (20). Four of 11 men (36%) and 8 of 11 women (73%) who were on sodium valproate had weight loss (ns).
CONCLUSIONS: Absolute weight loss is a significant effect of ZNS. In addition, women had a significant decrease in absolute weight after initiation of ZNS. The effect of ZNS on weight loss appears to be independent of concomitant AEDs. Additional analysis regarding dose, drug levels, and gender differences will be presented.
[Supported by: MINCEP[reg] Epilepsy Care]