Miconazole
"I have Interstitial Cystitis which is a horrible condition to begin with and like a fool I bought Miconazole to treat what I thought was a yeast infection.  Never again!  I used the three day and it caused horrible burning and itching.  Anyone who knows what IC is knows that patients with that condition all ready have burning and frequent urination, so this drug was certainly not helping but making me so much worse.  There should be a warning on the box not to use it if you have this condition!"