"i was prescribed this for mild anxiety after i was in a car accident and the headaches i got as a result. i took one 20 mg at night and woke up four hours later with the most horrible panic attack (that&#039;s what the doctor said). i&#039;ve never had that happen in my life. my heart was racing and pounding, i would get hot then cold and back again, i was shaking so bad i could hardly type. i wanted to cry but couldn&#039;t, scream or something. i felt like all of a sudden i had a different personality. my heart raced for 4 days after that. i never took another after that first one. i&#039;ve been having heart pounding sensations for days in the last three weeks since taking the cymbalta. "