I Have A Bitter Taste In My Mouth For About

I have a bitter taste in my mouth for about 3 months now. I take 3.5 mg of zopicone maybe 3 times a week. I am 66 years old and have quite good health and take no medications. I have learned that the taste in my mouth is from the sleeping medication. I am not going to take it anymore. How long before the taste will leave my mouth and would some kind of cleanse help speed up the process?