Are there any CB antagonists available?

[CrimpJiggler]

According to this article:
http://neuroskeptic.blogspot.ie/2010/02/decline-and-fall-of-cannabinoid.html
they experimented with CB antagonists as weight loss drugs, but dropped them because they caused depression in most people. These drugs are something I believe psychonauts should have in their toolbox, as emergency countermeasures for dealing with bad trips. Not just for reversing the effects of cannabinoid agonists, but I believe they would also help counteract paranoia and psychosis symptoms while on other drugs like psilocybin or LSD. Trazodone (a serotonin antagonist) is highly effective at ending serotonergic psychedelic (i.e. shrooms and LSD) trips and counteracting overdoses, but sometimes you just wanna counteract some of the adverse side effects like paranoia and psychosis, rather than reduce the intensity of the trip. I'd like to experiment with CB antagonists for this kinda thing.

Anyone know how to obtain them?

 

[FnX]

IIRC Cannabidiol aka CBD is an indirect CB1 antagonist, but I don't quite understand it's action exactly. - http://www.ncbi.nlm.nih.gov/pubmed/17828291

Here's another excerpt from wikipedia:

Cannabidiol has no affinity for CB1 and CB2 receptors but acts as an indirect antagonist of cannabinoid agonists.[8] Recently it was found to be an antagonist at the putative new cannabinoid receptor, GPR55, a GPCR expressed in the caudate nucleus and putamen

They also mention dose dependent antagonism with Delta9-THCV:

Delta9-THCV also interacts with CB1 receptors when administered in vivo, behaving either as a CB1 antagonist or, at higher doses, as a CB1 receptor agonist

Perhaps someone from the ADD could explain better how CBD works it's antagonistic magic?