What are the problems / adverse effects of neurontin (gabapentin)?

Ill effects of GABA. Neurontin (gabapentin) modulates excitatory neurotransmitter release and the side effects can be burdensome. These include the more common dizziness, somnolence, fatigue, swelling of the legs, nausea/vomiting, hostility tremor, blurred vision, headache and constipation to name but a few. If you experience any of these and they persist then you should contact your doctor to discuss further. Good luck.