Medicine Name: Gabacnx NT 400mg/10mg Tablet. Composition: Gabapentin (400mg) + Nortriptyline (10mg). Side Effects: Constipation Difficulty in urination Weight gain Sleepiness Dizziness Tiredness Blurred vision Dryness in mouth Orthostatic hypotension sudden lowering of blood pressure on standing Increased heart rate Uncoordinated body movements.