What about taking an empty pillbox and fill it like so:

Tape sticky notes on top of the M, T, W, Th, F, S, Su.

Write on the stickies: 1, 2, 3, 4, 5, 6, 7

And if there's a PRN spot, write 8.

If no PRN slot, it isn't a huge deal. Just remember that #8 comes from the pill bottle

Then refill everything tomorrow again. Rinse and repeat

Good luck!