Dontral Plus Dewormer

I have an 11 year old female Cavlier/Bichon mix who is 11 years old. She had 1 tapeworm in her stool yesterday. Vet prescribed Donatel Plus. I worry she will have a reaction. Anyone have experience with this? I Google and find everything from upset stomach to dog dying. She has a raised ALP level and an X-ray two weeks ago showed an enlarged liver, but I have to follow up on the liver.

If any of you have tried non toxic recipes for tapeworms that work, let me know. I have read about crushed pumpkin seeds as one.

Thanks!