I knew there was something about the 25 mg. Found it:
minneapolisnick wrote:
Seven weeks in and I still only take 25 mg of naltrexone when I know that my window of drinking will be between say, 7 PM and 10 PM. If you take 25 mg of naltrexone, wait an hour, drink and then finish the drinking within a few hours after that, you are fully covered. 50 mg covers you for 24 hours; 12 mg certainly will cover you for a few hours -- probably as many as 12. I personally don't see any risk of taking 25 mg if you know for certain you'll be done drinking within a few hours after taking the nal. Dr. Eskapa verified as much on this site with others who really wanted to stick at 25 mg in order to mitigate side effects.