Combining ultra low doses of naltrexone (ULDN) with opiates is gaining quite a momentum either to help the pain med work more effectively or to help those with tapering off opiates. Here is one Doctors account which may be of some interest to you (just fyi 10mcg is 0.01mg of LDN):-
"The manner in which I've used ULDNTX is to tell people to make up a 100 microgram/ml solution which can then be diluted further so that one can start very low and work up. The dose/response curve of naltrexone potentiation of analgesia appears to be parabolic; no response at too low a dose, a maximum response at a higher dose and then decreasing effectiveness as one continues to increase naltrexone dose. At some point, the dose of naltrexone will be high enough and it will be algesic; ie increase pain as it assumes its expected opiate receptor blocking role. The dose of naltrexone that will antagonize exogenous opiates and increase pain is quite variable among individuals. The lowest dose I've seen put a chronic opiate user into withdrawal has been 1 mg"
"Generally I suggest to patients that they experiment with combining microgram doses of naltrexone with opiate analgesics and I have seen reductions of around 50% in opiate analgesic doses when this approach has been used. One indication that a drug is doing something is when patients ask for more of it. I've had patients use opiates and naltrexone in combination and then come back asking for more naltrexone as it seemed to be helping with analgesia. My practice has been to give people about 5-10 1 mg capsules to start off with and then write prescriptions for further supplies of naltrexone. Doses that patients have been using range from 10 micrograms 2-4 times daily to 100-200 micrograms 2-4 times daily."