Sinicuichi (Heimia salicifolia) plays with nicotnic receptors a little bit, but it's more choline dominant in its actions. I've found it does make nicotine less effective similarly to Bupropion though, which is a prescribed stimulant that sort of resembles a wacked out amphetamine. Bupropion was originally used to help people quit smoking cigarettes since it renders nicotine inactive, and at least in the US it's handed out like candy. I've been given a 6 month scrip of it and a 9 month scrip of it, both on accident, for a single month. I just have a jar full of loose bupropion now as a result.
A note about bupropion btw; despite its wildly prevalent availability, it can kill without much notice if you push the doses too high trying to chase the unique high that it produces, especially if insufflated. Don't risk that, just get normal speed if you're after that.