Why does Nausea occur when using Opiates ?

[BottleDryer]

Sorry if this has been explained before but I can't find it with a search.

I found this note scribbled on a piece of paper on the train a few days ago;

"My question is, Why do we ( I ) feel nauseus after taking a "recreational" dose of an opiate ?
To give more detail;

I'm not a heavy user of Opiates, but the ones I prefer to take recreationaly (Oxy, Kratom) usually give me nausea.
I know it depends on whether you have food in your stomach or not, but I want to know why exactly does nausea happen.

Everytime I take an opiate (Percocet for example for my back) or Kratom (especially this stuff makes me wanna throw up).

To counter act the nausea I usually take some ginger root capsules and one Gravol tablet (Dimenhydrinate) 30minutes before an opiate dose and it works great.
But again, I would like to know why the nausea is involved in the first place ?
Can someone explain this to me ? "

End of message on the note.

 

[allegator]

It's mostly due to your brain detecting and then trying to expel foreign chemicals from your body.
https://en.wikipedia.org/wiki/Chemoreceptor_trigger_zone

Another factor which can contribute is opioids' effect on the vestibular system (controls balance) which can cause a feeling of spinning or dizziness.

Finally mu-opioid receptors in the gut inhibit the myenteric plexus (a layer of nerves between muscles which control GI motility) so it is more difficult to digest food and that can contribute to nausea as well as constipation.

 

[effie]

^ this :D

Gastrostasis (the gut slowing down, specifically the stomach in the case of nausea) is a big factor, so pro-kinetic (get the gut moving) antiemetics such as metoclopramide or domperidone are often tried first in hospital, but it is a combination of factors as allegator said.

 

[debaser]

I usually take 25mg of promethazine and no problem. I have some domperidone too but I never tried it. Also, take a light meal before indulging, as an empty stomach is a strong factor of nausea when using opiates. You can lie down a few minutes too if you feel nauseous, it does wonders

 

[effie]

Yeah a lot of antihistamines are good, especially the 1st gen ones

 

[BottleDryer]

Thanks for the replies guys and gal's.
Great info.