My nephew has been taking DDAVP since 1989, 4 sprays per day. The doc accidently sent in a new script for 8 sprays per day, which he was given for several weeks as directed by the doc. He had a seizure, taken to emergency, has been in IUC for 8 days now, Sodium is going crazy, he is now on a breathing machine, having siezures and strokes. I can't find anything about adverse condition on long term overdose on the meds. Doc said it has nothing to do with anything? Feeling lost.