I do not recommend Nizoral to people, mainly because it does not effect a lasting cure. Usually Nizoral is Rx'd to people with terminal AIDS who are suffering so terribly with impossibly malfunctioning immune systems. Nizoral is also used in hair and foot preparations for dandruff and foot fungus, respectively. Used internally it creates a huge overload on the liver... makes it work too hard, and thus wears it out. I had to practically get down on my knees and beg for this stuff. I went to the dr. armed to the teeth with information about what I had and what I thought would help me. Even then, I had to agree with the doc that I did not want to end up with a dead liver. So I took it for a week and stopped. It helped me over a difficult hump.
I work with an MD doc now in CA who Rx's Diflucan and Nystatin for me, but you can find your own by going to ACAM (American College for Advancement in Medicine): http://www.acam.org/dr_search/index.php
These drs. practice medicine, chiropractic, naturopathy, osteopathy, and other types of medicine within a holistic framework. The listing is for all over the U.S. and possibly Mexico and Canada now.
But it sounds like you will get nowhere with your current doc. S/he is not very well informed. This kind of dr. is probably too busy to work with you and do the research necessary to find ways to help you. ACAM is a highly respected association of award winning docs.
If I might ask, what are your symptoms? I think the folks here on the board have the right idea with cleansings first, along with diet, then supplements and herbal support. This approach makes sense, but it also depends on how severe your symptoms are and if your candida has gone systemic.