Metoclopramide is the most commonly-employed anti-emetic used with end of life drugs. Common brand names include Maxolon and Pramin. This drug performs two useful actions:
a) prevents nausea and vomiting by blocking dopamine b) increases the absorbtion of the lethal drug by facilitating gastric emptying
The usual regime is to take 3 x 10mg tablets (30mg) about an hour before the planned ingestion of the lethal drug.
An alternative form of administration is to take the drug for 48 continuous hours prior to the planned death at the rate of 1 tablet (10mg) every 8 hours (ie x3 per day). Note - this regime removes the need