Non-voluntary sedation

An elderly patient with end-stage dementia is taken to the hospital from a nursing home because he can no longer live at home or in a nursing home due to combative behavior. The care team wishes to treat him with intramuscular neuroleptics (antipsychotic medication) and return him to the nursing home. The treatment will also have the side effect of heavily sedating the patient, and because of this the patient refuses the treatment. What is the care team to do?