Weed causes anxiety attacks in lots of people, Killerweed, and doesn't necessarily have to have been laced. THC does that to lots of folks, as our long history of posts about this very subject attests to. You can find that reaction listed among all standard possible negative interactions with cannabis, too, like on Erowid.

The solutions for folks who have this reaction are fairly easy choices To stop smoking weed. To only smoke when you're in a particularly cool, calm frame of mind, and even then you might still have a panicky response. Or to try and find or grow your own Indica or Indica-dominant strains for a more sedating, calming effect. Sativas tend to be worse about producing the panic/heart-racing response.