Drug Interaction help needed

I have recently been prescribed Meloxicam and Nortriptyline for Fibromyalgia pain. I have had FMS for 7 years and am being taken off of Tramadol as it has been making me sick, even with the cannabis use. I know that Tramadol works the same as these two new meds and I have no issues with my cannabis use, but I can't find reliable information online on the drug interaction. I have seen that you shouldn't take cannabis with Nortriptyline, but it doesn't say why.
Anyone have reliable information, links, personal experience? TIA