I Have A Prescription Of Lunesta And Have Noticed That

I have a prescription of Lunesta and have noticed that about 30 minutes after I take it I get a distinct sour, almost intolerable taste in my mouth. I have tried many ways of taking it. Have seen nothing of others having experienced this. I am used to the taste of a variety of pills and this is by far the worst and inescapable for me unless I just do not take it. Any feedback would be appreciated.