Hi Jane, firstly a warm welcome to you here at Talking Point, so sorry on top of mum being recently diagnosed with dementia, the dreaded panic attacks hsve reared their ugly head, my mum and alas also my mum in law when starting the road to dementia journey, both had these, the panic attacks seemed to happen before really noticeable changes
mum has Alzheimers and mum in law vascular dementia (for which Donepezil is unsuitable) alas a mild chemical cosh was needed for them both, lorazepam and Mirtazapine, just to help calm but not make them like zombies,so a home visit by the GP would be the best place to start and if possible keep notes on when and what time mum is more agitated and let the doctor know, with the weekend coming up..which I think we as carers all dread at times, maybe a call to them before end of surgery tonight to see if they can advise you how to get help "after hours" without subjecting mum being admitted to hospital should she be in so much distress.
Hope you get help today
Best wishes
Chris