There are two other plants that, for me personally, have always been very effective against nausea.
The first one is ginger. Ginger is as far as i'm aware completely safe and without serious side-effects.
The second one is cannabis. Cannabis ofcourse, is a psycho-active itself, that has a very powerfull synergy with all of the serotonergic psychedelics. I personally like this synergy, but many people find it too unpredictable and powerfull.
I have taken cinnarizine once with ayahuasca, expecting a brugmansia-like potentiation, and the effects where extremely unpleasant. Breathing became very hard, as if a pregnant elephant decided to spent the night, sitting on my chest.
So i personally would avoid all antihistaminic drugs with ayahuasca.
Brugmansia is, as we all know, a pretty dangerous plant to experiment with. But it is possible though, to use it as an aya admixture in a way that is relatively safe.
The ones you can buy in gardencenters are usually brugmansia arborea, brugmansia aurea, and brugmansia suaveolens.
These plants all contain tropanes, but the concentration in the leaves is not very high.
If you soak one small leaf in an ayahuasca brew that is still warm, but not very hot, some of the alkaloids will get in your brew, but by far not enough to do any harm (to an adult of average weight anyway).
The danger lies mostly in the use of seeds, roots, and larger quantities. And in regular use that causes tropanes to accumulate in the bloodstream.
Pushing boundaries with these plants, and experimenting with larger quantities, is likely to at some point, result in something realy bad.
The first noticeable side-effect is a dry throat. Difficulty urinating can also be experienced with relatively small doses.
These effects can already occur when doses that are by far not dangerous yet, are taken. A dry throat is no immediate reason to panic.
Blurred vision is definately a sign of intoxication though. But even blurred vision does not automatically mean you are in the danger zone yet. It is to be avoided though, and definately a sign you have taken way more than needed.
The moment you start to feel your muscles getting weaker though, that's when you definately should call the emergency line. If you have trouble lifting an object like a teapot or a bottle of water, you are in serious danger and mere minutes away from a delirious state or losing counsciousness.
If blurred vision or a dry throat occur only minutes after ingestion, that is also a sign you're in serious trouble. It would normally take about an hour or so before these milder side-effects are first experienced.
I would disrecommend taking these plants anyway, but if you would decide otherwise, these are the things i can say from personal experience.
