Medication stopped

Hi everyone,my elderley mum has recently had some bad experiences at home with changes in her mental state,fearful of being left alone,lots of scary hallucinations,forgetfulness and uncharacteristic actions.She is in hospital at the moment while they are observing her,they have stopped one of her parkinson meds,Ragasaline and another Trospium,and started her on Risperdol to help with the hallucinations.
Has anybody had experience of going through very sudden changes in themselves like this? It happened over a course of around two weeks and progressed very quickly. She has been checked for UTIs and bloods all okay.
She has had Parkinsons for seven years.
Any advice would be very grateful.