Mamagus,
I too, have a standard poodle who has seizures. Hers will last up to 6 or 7 minutes; and she is pretty out-of-it for a good 30 to 60 minutes after a seizure. Fortunately, she only has them every few months. I treat her with Phenobarbatol (sp?), only after a seizure: one as soon as I can get her mouth open since during a seizure her jaw is locked shut, and a second pill 12 hours later. BTW, she has had them almost all her life; and she is 14 now.
I recommend you go back to you vet and ask more questions (don't forget to cover the agressive behavior), after you go online to the Amer. Vet. Assn. website and read up on seizures. Food alerigies cause a lot of problems, and you may want to have him tested. Then, if you still feel like you need it, seek a second opinion.
Several people have stated that the medicine has a lot of negative side effects, and I agree. If you can hold off on the medicine for a while, it would be better for your beautiful pet.
One thing that you do need to know: once the neuro-pathways are opened up for seizures, they 'connect' faster each time another seizure happens. You will want to keep track of them so your vet will have good information when the time comes for your pet to be placed on meds. Make sure you know what to look for so you'll be able to recognize when he has had a seizure when you weren't present.
Good luck, and belly rubs to your pet.