I would determine what the ingredients are in your medication. I saw one where (benadryl) it contained starch and cellulose; these ingredients will feed the candida. How much? Its hard to say, but it doesn’t help the treatment.
I was able to get over all of my allergies by doing the diet for 4 months strictly; I hope the same goes for you. Also, in general the website states no medication is allowed (I am personally am taking sleeping medication for my chronic insomnia, and hope to stop this in the near future).
I think in general, any use of meds/drugs will prolong the treatment. Also, I am no candida expert, so take my suggestions with a grain of salt. I recommend finding a naturopathic doctor who can help you find alternative treatments for your symptoms; remember the dr.s come out like colors in the rainbow, so finding a good naturopath is recommended if you want to get better faster.