Vicodin and muscle pain

I've been prescribed Vicodin for chronic back and muscle pain. I 've been taking this medication for over a year. I experience NO side effects and although I am probably addicted,one tablet (10mg) daily allows me to live a normal life and carry on my normal activities. I hope that this drug is not causing damage t my liver or kidneys or any other organs. I dread the day that the Doctor takes me of the medication and then not only will I have pain (unbearable at times) I will also have to endure the withdrawls.
I read where people become constipated. I have to ask myself, could it be their diets or other medications causing this problem. For now, I am satisified with the results that I am getting and can only hope that the medication continues to work for me. D.O. Kentucky March 23,2005