Hello. About a decade ago, I was prescribed effexor for generalized anxiety disorder. While on the medication, I don't recall any side effects - it was only when I would miss a dose that I would feel withdrawl symptoms very quickly (shaking, electric feelings, skin crawling). At any rate, I stopped taking effexor about 7 years ago, and had no real anxiety issues. I've been pretty much fine for years, until around December of this year when things came flooding back. To keep it short, my doctor prescribed me venlafaxine, which is the generic of effexor. Since being on the drug, my right arm has been getting progressively more and more tired. My right leg has similar issues, but not as pronounced as my arm. My left appendages are also "burned out," but nowhere as much as my right. My upper back and neck muscles are also starting to feel tight. I'm not sure if it's related to the venlafaxine, or if I actually have something else going on. My biggest fears are neurological diseases.
The best way to describe my "weakness" is to say it feels like I just lifted a ton of weights - only all of the time. I feel stiff and have muscle twitches all over my body, with slight muscle cramping (nothing too horrendous). I originally went to the doctor because I was feeling tired and a bit dizzy and "out of it" all of the time. I had some muscle weakness, but nothing this pronounced. Additionally, since being on venlafaxine (I'm up to 75mg a day, which is what my effexor highest dose was), my head is clear - it's just this muscle fatigue and tense feeling that's driving me nuts.
Is venlafaxine different from effexor as far as side effects are concerned? Can muscle weakness/burn occur in just one arm and leg when associated with anxiety?
Any thoughts would be appreciated.