http://www.bluelight.org/vb/threads/542 ... ck-opiates

Just out of interest.. this is a thread from a drug addicition forum, this guy takes 50mg of Nal and then sees when he can get a hit from oxycodone.. even after 24 plus hours no hit.

I'm not saying that's very scientific but put me to thinking if I missed a booster I wouldn't worry.. but never miss one after 24hours

This an excerpt from Roy Eskapa:

Naltrexone 50 mg will block the effects of opiates and endorphins for 24 hours. Doubling the dose may increase the metabolite half-life to 48 hours ... However, there may be individual differences and some may metabolize it more rapidly than others. Thus if you take the tablet at 8 am and start drinking at 10 pm you may not be covered. There is a reason why we only want you to take the medication 1 hour before drinking not more. There is no benefit from blocking the endorphins before they are released as a result of drinking. Moreover, if you take naltrexone with abstinence for extended periods you will 'upregulate' your opioid receptors - meaning there will be more of them (millions more) in your body. If you drink at this point without coverage (opioid blockade / antagonism) you will receive an especially strong jolt of reinforcement from the endorphins thereby enhancing your craving and drinking levels.