There's an incitement to use an incrementally higher dose of Naltrexone after a while if you drink everyday and therefore are taking the medication daily. This is due to an apparently upregulation of the opioid receptors:

"High doses of Nx are required to suppress continuous access alcohol consumption in P rats, and tolerance develops to the ethanol consumption-suppressing effect of Nx that may be related to increases in μ-opiate receptors."

http://onlinelibrary.wiley.com/doi/10.1 ... x/abstract

"Opioid receptor upregulation can develop simultaneously with suppression of drinking and may partially counteract the clinical benefits from NTX in the treatment of alcoholism."

http://www.sciencedirect.com/science/ar ... 2900000914

"The data suggest that continual long-term naltrexone treatment may not be effective in the treatment of alcoholism, possibly because of the induced increase in micro-opioid receptor density."

http://www.ncbi.nlm.nih.gov/pubmed/10397284

This can partly explain why some people need to use higher doses of Naltrexone than others. Especially if they drink everyday for a prolonged period of time.

Awesome Martrol , ty for sharing your research. This may prove to be very helpful to some. Applause