What can I do about my vicious cat?

Two weeks ago my husband and I moved with our two 14 year old strictly indoor cats. They were fine at first but three days ago the female started viciously attacking the male cat and me. I took her to the vet and he examined her and said she seems perfectly healthy and gave me mood stabilizing pills but they aren't helping. I am afraid of her because I can't go near her without her hissing and growling and attacking me. My husband is on chemotherapy so if she scratches or attacks him it could be very dangerous to him. I'm afraid I'll have to have her put down if I can't get her to stop this. Any suggestions?