nausea/vomiting
"I have type one diabetes so not being able to eat, due to nausea and vomiting, can really throw blood/sugar levels off in a hurry.  My doctor prescribed trimethobenzamide for me many years ago, when I was suffering with the flu and it worked extremely well and almost instantly, so I've always requested it whenever I've had problems with nausea which (thankfully) is very infrequently but it's been (possibly literally) a life-saver at those times!!!"