I started Effexor last Friday. Ever since then, I have had a pounding heart, blurred vision and dizziness. I thought the pounding heart was coffee, but I stopped drinking it with caffeine and it didn't help. Yesterday and today I feel like I am starting a panic attack. My chest feels heavy, it feels like I can't breathe and I am shaky. I have had panic attacks before and this feels like a mild one. I have a call in to my doctor. Has anyone else experienced a worsening of their symptoms with this medication? I stopped taking it today (since I have only been on the 37.5 mg. dose for a few days) but I still feel the same.