Read on Twitter
Quick thread of three points: this is pharmacologically interesting and it may not work; the market for this may be limited; & there is substantial prior art that will make it hard to get a patent https://twitter.com/PsilocybinAlpha/status/1362018510587707392
Stopping an LSD trip with a 5-HT2AR antagonist might be harder than stopping trips from other psychedelics. When LSD binds to 5-HT2AR, it seems to pull part of the receptor down, forming a lid. This may explain why LSD trips last so long, despite the modest plasma half-life.
If LSD is slow to leave 5HT2AR and ketanserin can only bind to unoccupied receptors, ketanserin pretreatment might prevent trips while post treatment may be ineffectual at ending them (Previous image and lid concept from Wacker et al 2017 http://dx.doi.org/10.1016/j.cell.2016.12.033 )
It's also unclear how much of a market there'd be for trip stopping. Many therapists would say that working through challenging experiences is important to therapeutic value and that stopping trips when they get challenging might be anti-therapeutic.
Finally, the idea might be too obvious-to-try to be patentable. Given that Liechti and Vollenweider already showed ketanserin blocks trips from starting, it seems obvious to try it for ending trips. Plus, at least one vendor was selling it for this purpose a few years ago.
From a scientific point of view, I'd like to see a study comparing ketanserin's ability to terminate trips from LSD versus a tryptamine such as psilocin where the lid is not thought to be a factor.
