I've noticed a lot of the talk concerning low dose naltrexone and its relation to opioid-based pain relievers refers to people who are on them long-term and use them for daily pain therapy. *** "Because LDN blocks opioid receptors throughout the body for three or four hours, people using medicine that is an opioid agonist, i.e. narcotic medication — such as Ultram (tramadol), morphine, Percocet, Duragesic patch or codeine-containing medication — should not take LDN until such medicine is completely out of one's system." *** But if LDN only blocks these receptors for only 3-4 hours, as the above mentions, why can't we take any opioid pain relievers during the day, especially if the pain relievers WOULD be out of your system by the time your nighttime LDN dose came around? If the half life of Vicodin is around 4 hours, and I only take half-a-tablet on the days where I have severe headaches, it seems to me that the medicine would be out of my system by the time it came to taking my LDN dose at night. Am I missing something?