The influence of concurrent anticonvulsants on the efficacy of the ketogenic diet.

It is unknown if any particular anticonvulsants modify the likelihood of seizure reduction when used in combination with the ketogenic diet (KD). A retrospective study was performed of 217 consecutive children who started the KD from 2000-2007. Patients included did not have any changes to their anticonvulsant dose. Efficacy data at 3 months on the KD were analyzed with respect to the six most frequently used anticonvulsants in this cohort. A total of 115 patients were included. Children receiving phenobarbital in combination with the KD were significantly less likely to have a >50% seizure reduction (p = 0.003). Conversely, those receiving zonisamide in combination with the KD at onset were more likely to have a >50% reduction (p = 0.04). These results provide practical information to clinicians who are treating children receiving both the KD and anticonvulsants.