The high lipid-solubility of cannabinoids results in their persisting in the body for long periods of time. Even after a single administration of THC, detectable levels of THC can be found in the body for weeks or longer (depending on the amount administered and the sensitivity of the assessment method). A number of investigators have suggested that this is an important factor in marijuana's effects, perhaps because cannabinoids may accumulate in the body, particularly in the lipid membranes of neurons.
Did you get an answer for this? I have the exact same scenario. I'm treating my TN with Tegretol, and recently tried CBD. I think I took too much and there are some weird drug interactions with Tegretol and I felt quite stoned....was alone and talking to myself in my head thinking I was Einstein. It freaked me out a bit but I think I took too much. I'm trying lower doses again as recently my TN seems to be resisting the meds, although I have had a lot of emotional stress, which seems to be a trigger. Thanks!! Anna