Feeling nausia if dont take omnicortisol

My mother had adernal gland removal surgery on April month this year .Surgery is suggested due to tumor on her adrenal gland due to excessive cortisol .After operation she was feeling nausia at that time doctor suggested some medicines and due to which she was comfortably eating and now doctor suggested to not take that medicine as that medicine is steroid but she is trying to avoid that medicine like taking alternative day or half dosage but after some days like 5 6 daya she again feel same medicine name is OMNICORTISOL . How can she avoid that medicine and can have her normal intake of food .I have also attached latest prescription from that only omnicortisol and thyronorm is going on rest all are for her temporary sinus and cough