Just found out today that dad did in fact give mam some calpol (bit confused as to which night, or whether more than once) and apparently it had an adverse effect when they went to bed - dad's words were 'she went berserk', getting in and out of bed every few seconds for over an hour, although we don't know whether it was just a coincidence. Also, he said she was very strange after taking the calpol (just 5ml) and the carers were worried.
This has put him off trying paracetamol altogether.
I just don't know what to suggest anymore as everything I do suggest seems to backfire.