Nothing in this post should be construed as medical advice. Please consult your physician or pharmacist for information about side effects of prescription drugsIf I were having such severe reactions to naltrexone and I wanted to try to minimize them I would try in this order:
1) have some food in my stomach
2) take 25mg or 12.5mg to start with until nausea subsided
3) be aware that the same amount of alcohol will cause worse hangovers, reduce the dose of alcohol using whatever harm reduction strategies and tricks at my disposal.
4) be prepared for side effects to persist for up to 2 weeks before giving up on the experiment.
Here is a discussion of why we get nausea on naltrexone.
http://www.thesinclairmethod.net/community/viewtopic.php?f=6&t=2199&hilit=+nausea&sid=34be5f7b168c1f037ad0a14c2a7f6df1 In short it has to do with naltrexone creating a withdrawal like state by blocking your body's natural opiates (endorphins). Have you ever read a story of a heroin addict going cold-turkey and having withdrawal? Vomiting features prominently in the withdrawal. It's the same principle here only not as severe as what the heroin addict experiences since their vomiting lasts for days. I hope it gets better for you.