...but until they are medicated and the hallucinations contained it seems as though they will be stuck in the fear of the moment forever.
I thought this needed added emphasis. I agree completely. However, LE can not do this for you, only the approprite medical provider can, be it at the facility or an ALS unit. If you are truly worried about the possibility of being unable to talk this person down then it is inhumane to simply have them tied down, be it by handcuffs in the back of a squad car or leathers on your cot. Do everyone a favor, be a patient advocate and work on getting the approprite sedation on board however you can.