I woke up about 2:30 this morning and my head was just pounding. I've been trying not to take any other medications since I started on Zonegran, to try and keep things as clear-cut as possible, but at that time of morning, I just wanted it to stop. So I took something. I managed to get back to bed and sleep for another couple of hours.
When I could sleep no more, around 6:00am, I took another 200mg pill, and that carried me through lunch or thereabouts. Unfortunately I had no more easy access to the bottle or I likely would have taken even more - but I didn't, since the bag was overhead in a bin. I took one more 200mg pill before going to bed at about 11pm, for a total of 600mg during the day.