When you are reading back a verbal order...

If you are reading back a verbal order or reading a med list or calling in a prescription or whatever and it is something like Vytorin 10/40, how do you read it back? One of the nurses in my clinic says "Vytorin ten-slash-forty", one says "Vytorin ten forty", and I was taught it would be "Vytorin ten per forty." I read a med list to one of the ER nurses yesterday when she called to get a med list for a patient and when I said "Vytorin ten per forty" she about came unglued...she made me repeat it three times and finally, I spelled it and then said one zero slash four zero, before she got what I was getting at. She called later and said she had no idea what I meant when I said ten per forty. When I explained what I meant, she said that she had never heard it that way and that I needed to "standardize my terminology."

Ten per forty is how the pharmacist reads it back when we call orders in...ten per forty is what I was taught in nursing school and paramedic school, and ten per forty is what the Vytorin drug rep says...am I wrong???