What cures the opiate hangover is diphenhydramine against the vomiting and sickness + ibuprofene or metamizole for headache and then drinking lots of water. If its not a really terrible case, where you feel sensitive to any external stimuli like light and sound, i am fine most of the time after this. The feeling of being on the edge of vomiting or vomiting itself can be so much worse then the headache itself. IF i get nauseous from opiates it its always the day AFTER i have used (too much at that time).
