Hi Norman
I think it could be either the infection itself, or the tablets - or even both.
Bad throats can be really painful, with lumps coming up, constriction of the throat, difficulties in eating, temperature etc.
We can get quite abrasive to others when a bad throat is niggling, but we can explain that we have what we have, and why we are like that. For someone who feels what they have, but may not be able to comprehend exactly what it is, or who may even blame others for how they are feeling... well another nightmare of dementia.
Then there are the medications. They may hurt when being taken,all have their own possible additional effects - then there is the fact they have to work with Aricept, and possibly other medications as well.
Sorry - I'm sure I'm saying nothing you don't already know.
I hope Peg improves soon.