In Australia, I agree with her. In the US, Benadryl is Diphenhydramine, which is an excellent antihistamine. In Australia, Benadryl is Cetirizine, which is far less powerful for bad histamine-related reactions. Phenergan would be a better choice. Sounds like you have an excellent pharmacist there, be nice to her, she is a keeper!
I have a personal hatred of Cetirizine. Despite the fact that it is not meant to get into the brain very effectively, it makes me dizzy when I move my head. Very odd response to it, but very consistent. I was given it when i had a horrible outbreak of hives. The hives were less bad than the dizziness! 