Hi, There is no known interaction between Gabapentin and Naltrexone. However, there may be development of serotonin syndrome or increased severity of this syndrome in some cases with tramadol, particularly when used with some medicines including naltrexone. Symptoms of serotonin include- altered mental status, neuromuscular abnormalities etc. To summarize, about your query, you can continue, your gabapentin, even while using naltrexone, without probability of any interaction. Hence, you should continue, this drug till advised by your physician and only try to wean off from gabapentin, under guidance of your doctor. About use of Tramadol (trampoline), you are advised to be cautious about any change of your mental status or presence of any involuntary or jerky movements of muscles and if symptoms develop, you should stop using this drug. Even also, you can use of some other analgesic, if really needed, which has not been linked to the development of serotonin syndrome under guidance of your doctor. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Satnarain Bansal, General & Family Physician