When I was going through chemo, they prescribed Zofran, which seemed to work the best for me. The usual dose is 4 mg. However, insurances will only pay for 8 or 9 tabs per month, and it's never enough. I had some pharmacy friends who suggested that I get the doctor to order Zofran 8 mg, then you can break the tabs in half, and double your amount. It worked for me, anyway. Usually Dr's will be pretty understanding about it and work with you. Good luck!