Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concerns.. As per your complain dry mouth is a side effect of Neurontin that contains active ingredient Gabapentin as well as dry mouth is also a common side effect of diabetes in case if your blood sugar is high.. Swollen and painful taste buds along with soreness in mouth can be due to inflammation in the mucosal surfaces inside mouth secondary to dry mouth.. I would suggest you to consult your treating physician and get evaluated and he can advise you to get your blood sugar investigation done as well as he can also alter the doses of oral hypoglycemic drugs to maintain your normal blood sugar levels.. Along with it he can also alter the doses of Gabapentin to relieve your dry mouth.. You can also chew sugar free chewing gums as it helps in stimulating saliva flow.. Drink plenty of water.. You can also instil artificial saliva drops in mouth for lubrication.. Avoid hot and spicy food and gargle with numbing mouthwash to get relieved of pain.. Hope this information helps.. Thanks and regards. Dr.Honey Nandwani Arora.