"doc switched me from ambien to lunesta after about 7 months stating that ambien is known to cause parkinsons&#039; longterm.  it worked similarly at first, but because of its long half-life i was told not to take another when i woke up early morning , 1-3 pm.  this is  big problem because i cannot get back to sleep.    both 5mg ambien and 3mg luniest give me 3-4 hours sleep.  with ambien, id awake and take another 5mg and go right back to sleep.  now i can&#039;t do that anymore and seldom have any sleep quality after 2 pm.  copper taste didn&#039;t bother me at first, but now a month later,  i notice everything tastes different, even water....was hard to pinpoint, but finally realized it was a metallic taste that was permeating everything i ate. or drank"