Can Effexor Completely Cure Cataplexy?

My 8 yr old son has Narcolepsy/Cataplexy. He is on 150 mg Effexor XR and 1.5 grams Xyrem 3x/night. Yesterday he missed his dose of Effexor in the morning and he suffered from a LOT of Cataplexy during the day. Should I be concerned that his cataplexy is getting worse and the Effexor is "masking" the problem? Can the Cataplexy get progressivly worse? With Narcolepsy, is there any way to "cure" Cataplexy or is it simply treating the symptom of Cataplexy?