My mother has Parkinson's and dementia, and I'm concerned about her medical decisions. Is guardianship the right direction?

My mother has Parkinson's and dementia. I am already on her bank account and am mainly concerned about her medical decisions. Hospitals have refused to listen to me when I advise them what her primary and psychiatric doctors have told her and me about her meds. She also has had a pain med dependency and that has been a major issue in hospitals that want to prescribe what she shouldn't have. She is not totally incompetent, but her ability to rationalize and make rational decisions are severely and increasingly hampered. Is guardianship the right direction?