I dont think it really matters. The doctor at the walk-in clinic told me to use miconazole...the baby's ped. gave him nystatin cream for his bum and told me it would work on my nipples as well. I ended up using the nystatin, and used it in conjunction with the diflucan. Hope that helps.
You can also use gentian violet - you can get it at the health food store, it will stain your breasts purple and you babies mouth too, but its a good option to try before prescription medicines and if it doesn't work then you can always move onto prescriptions. Here is a link to a website that has lots of good information on both nystatin and gentian violet http://www.mercola.com/2004/oct/13/yeast_infections.htm. I hope this helps. I know how uncomfortable it can be to have a yeast infection on your breasts. Mine went undiagnosed for 4 weeks before I got the proper information and treatment.