Today when I got my prescription filled I got a different brand with a k 8 on it and one time before I got a different brand with a v something on it and it was like not taking anything at all and I was wondering if anyone has experienced the same situation. Are the k 8s as good as the m-15s. I called the pharmacist back and he said that was the only brand he had right now because I told them the last time the other brand did not work for me and I only wanted the m 15 that did work for me. I have not used any of them yet because he said if he got some in he would trade back with me.