Limited evidence suggests that 
carbamazepine may decrease 
methylphenidate levels. 
 It would seem wise to monitor the response to 
methylphenidate treatment carefully in patients taking 
carbamazepine. Note that the manufacturer says 
methylphenidate should be used with caution in patients with 
epilepsy, as it can, rarely, cause an increase in seizure frequency. If seizure frequency increases, 
methylphenidate should be discontinued.