atrial fibrillation
"Was prescribed this for Atrial Fibrillation. After ONE dose, I experienced: light-headedness, nausea, dizziness, chest pain, fast heart rate, high blood pressure, severe depression, slightly blurred vision, fatigue, anxiety, heart missing a beat often.  At the time of writing, it's three days after my one does (I stopped it immediately) and am still encountering some of the above side-effects.  I am on no other medications, nor have I been."