A problem with the anti-emetic drugs like Ondansetron (which is very expensive so you are unlikely to get many on the NHS) and Metachlopramide is that they work by stimulating the central nervous system so can make adrenaline anxiety worse - if you have this symptom. When I took them I felt manic, restless and had a full on anxiety attack on one occasion. This may not happen to you though if you have low oestrogen in post rather than perimenopause. So can only give my experience.
Domperidone, which empties the stomach more quickly, helps some women but again it's a stimulant (as is ginger).
Strong antihistamines that lower nausea, like Cyclizine, calm the CNS so also relax you but do cause drowsiness and then grogginess later on, so only good to take if getting 5am nausea and can sleep in for a few hours.
The most effective remedy I found was a non drug medicine called Emetrol, but it's not sold in the UK so can work out expensive via Amazon as one dose only lasts an hour so you can get through a lot! I got the tip from a pregnancy website and it really is amazing stuff, think it's phosphorus which slows down digestion, just can't work out why we don't have it here as its sold over the counter in Australia and the US very cheaply and has won awards.
If you can stop the source of the nausea with lowering oestrogen surges, if they're the cause, then even better.
Good luck!