"i have had insomnia since a hysterectomy in 2009, so began taking benadryl but that had the opposite effect on me &amp; i became very jittery w/ &quot;restless leg syndrome&quot;, so tried unisom 25mg nightly.  i have been taking unisom now for 6 years and it has worked pretty well to help me sleep at night.  however, 2 months ago i developed a fast &amp; irregular heart rhythm.  i am a nurse, so listened to my heart and could hear the missed beats when i felt them.  it felt like i had just ran up a flight of stairs but i wasn&#039;t out of breath.  my heart was just beating very rapidly and irregular.  couldn&#039;t figure out why i was having palpitations so quit taking &amp; saw dr. diminished palpitations since i quit taking &amp; all my heart tests and labs are normal."