Many can be fatal,some of the most fatal are the semi synthetic opiods or opiate pain killers such as Fentanyl,buprenorphine,oramorph,morphine etc if take by patients who have never taken opiates or...
Motilium or its generic name Domperidone 10mg,has fairly recently come off the prescription only list and is a very good anti nausea/vomiting drug,I have used it for years and had no side effects...
Medication to control vomiting?.
Emetrol is a liquid phosphorated carbohydrate solution available at most US drug stores.
Also available as a generic "anti-nausea" product.
No prescription required.