for SN?
I thought they are not very important. I was wrong.
They can make the difference between failed attempt or successful attempt. Or more suffering vs less suffering. They make you vomit less (or not at all) and they have prokinetic properties - means more drug is absorbed quicker (and you want your SN to be absorbed as quick as possible).
You should always go for antiemetics and fasting.
The top1 drug is Metoclopramide. I struggled to get it, but on my third doctor tele-visit I told her I have vomiting, dry heaving, reflux (GERD) and she prescribed one pack of meto. Two previous docs didn't. So its possible to get it but its not easy. (im from Poland).
Top2 and only other viable drug is Ondansetron. If you cant get meto, go for ondansetron. But its also prescription only.