Can a cat be sedated with dramamine?

My auntie wants to try to sedate her cat so she can try to get the horrible mats and tangles out of his fur. She says she'll use dramamine, but I told her I'd try to find out first if it's ok to use. I doubt it will sedate the cat enough so she can clip and brush him. I say she should pay the extra money and take him to the vet to have it done.