Naltrexone for cravings?

Has anyone ever taken naltrexone for cravings? I took it a few years ago and it made me feel nauseous I figured it was probably because I was still drinking. My dr suggested I try it again now that I’ve tried it for several days…I dont feel any different…just nauseous again! Does anyone else have an experience with this? My dr swears by it? But I’m not sure?

Common Side Effects of Naltrexone
Nausea, vomiting, diarrhea, or constipation.
Stomach pain or cramping.
Loss of appetite.
Headache.
Dizziness.
Nervousness, irritability, or anxiety.
Tearfulness.
Increased or decreased energy.

I have all of these! Maybe my dose is to high