carson and her seizures

It seemed like Carson wasn't having very many seizures, they were becoming far apart from one another. Four days ago she had a cluster seizure and I had to inject her up the rear to have them stop. Last night she had another cluster and I had to inject her again. We have an appointment Wednesday to get more injection...we had her on a pill when she first started the seizures but that didn't work...she was so doped up and not the same dog...and she continued to have seizures on them. I don't know why she has them or what we can do to help her. Anyone heard of this and has any suggestions?