I have been on Neurontin for over 10 years. I am taking Neurontin for PHN. When I was first given Neurontin, I could not take the med. as prescribed. I too would fall asleep. It took a whole year before my body adjusted to the med. I now take 2700 mg. daily. Along with Tramadol. I have the rare side effects but can not quit taking the med. for fear of having a more severe pain if I don't take the meds. I have recently noticed the weight gain. I continually think I have other things wrong with me, but when reading the side effects, I fit almost all the symtoms. Low back pain, bloated full feeling, body aches, buring eyes, change in vision, clumsiness, constipation, decrease in sexual desire, eye discharge, increased sensitivity to pain and touch, indigestion, nervousness, redness, trouble thinking, and loss of strength.