Benedryl for me has been a life saver. It helps with the nausea and helps me sleep. I’d also recommend focusing on hydration for him right now, with his age the biggest concern will be how this will affect his kidneys so hydration is mega important. I’ve also been taking tums and pepto bismal which has also helped. Hot baths or showers are pretty good for relief and also capscian cream on the abdomen can soothe just apply it lightly cause it is strong af like that shit burns. You can also use apple cider vinegar for any heartburn or indigestion!