Efudex - different stages of erosion

I just completed a 17 day (2 times per day) Efudex treatment on my face. I had some areas that were scabbing, slight bleeding and I'm assuming in the erosion phase. I had planned to go 21 days but I just couldn't take it anymore. I'm wondering if others who have completed this treatment would continue to use the cream only on the spots that had not reacted as quickly or is it recommended to continue applying it everywhere even though areas are at different stages.. I also had nausea and just felt really lousy and I don't understand why some patients are prescribed Efudex only where others are combined with the calcipoyriol.. Has anyone out there been given a reason by their dermatologist? I have not follow up at all and won't see her until Sept.. I'm interested in opinions and thoughts..Thanks so much Kathy