Perhaps the doctors don't realize how much pain your Dad has.

Leonard,
I was prescribed a generic for Loritab known as Hydrocodone-APAP solution by my ENT when I had my Tonsillectomy and Neck Dissection.

Then, again a RO prescribe the same for me to have on hand during Radiation Therapy (I didn't realize it was the same until I picked it up).

I only had pain from the Tonsillectomy and a teaspoon of the Lortab every few hours took care of it and I could easily eat soft foods.

I have over a bottle and a half of it left.

I also was prescribe Lidocaine 2% Viscous Solution to help me swallow when I got mouth and throat sores from RT, but I never got any and I have never opened it.

I was told, unlike that Lortab, the Lidocaine doesn't stop pain for very long.

Lortab seems pretty common and I was told by a RO at the cancer center that for pain management it is what they normally like to start with and keep meds like the patches in reserve for when other pain meds fail.

You need to have a serious talk with the doctors and insist on something. You might mention the Lortab. Your Dad can only go a few days without fluids before he becomes dehydrated.