The problem is that every plan, every state is different. Sometimes the plan is even different depending on the employer you get it from.
You can try this program
http://www.togetherrxaccess.com/index.html
to see if the company will help out with meds. I think it is mostly for people who don't have coverage, so I don't know if it will help you.
The home health thing, like everyone else suggested is a way I got around restrictive limits and copays for zofran. I used the subcutaneous pump (from the home health company Matria) and got it covered 100%, it does involve needles, but they are tiny, and you don't need an IV.
I was also wondering if your pharmacy copays go toward your annual maximum? If you have to pay any coinsurance for the rest of your care, you will most likely hit your annual maximum this year unless it is really high, so you might as well pay for the zofran now, because you won't have to pay for the other things later.