I did this once and called the pharmacy. Apparently keeping it cold just prolongs its shelf life, so put it back in the fridge, its still okay to use but may not be as effective toward the end of the month...you may need to refill a little early if you start to notice its not working as well.
Thanks! The first bottle I ever had I didn't refrigerate b/c it never said to and the pharmacist never told me to. Oops! It is almost gone anyways so I need to refill it soon.
Re: Prilosec users