In my experience, talking to someone while they’re high is amusing in short bursts and frustrating otherwise.

That’s how I felt while watching “American Ultra,” an ultraviolent, weed-fueled power fantasy starring Jesse Eisenberg and Kristen Stewart. The small chunks of entertainment peppered throughout its brisk, 96-minute running time aren’t enough to salvage the rest of it, which ranges from boring to downright annoying.

Mike (Eisenberg), a stereotypical aimless stoner, lives in a dingy house that probably smells terrible in small town West Virginia with his girlfriend Phoebe (Stewart). He works a dead-end job at a convenience store and has intense panic attacks whenever he tries to leave town, leaving him pretty much stuck in mud for the foreseeable future.

It turns out he has those panic attacks because, unbeknownst to him, he’s a CIA sleeper agent with advanced combat training and mental conditioning designed to keep him from leaving town.

A cartoonishly evil CIA man played by Topher Grace decides Mike needs to die for the fun of it. Mike’s inner prowess is unlocked, and the audience is treated to a little more than an hour of extreme, absurd violence punctuated by bits of stoner comedy.

On its own, the premise has some potential, and “American Ultra” occasionally lets it shine through. Eisenberg downs a couple dozen government baddies in ridiculous ways, such as throwing a frying pan into the air and ricocheting a bullet off of it straight into someone’s stomach in slow motion.

Really, it’s everything else that sinks the movie. The performances are fine (particularly Grace, who acts like the word “subtlety” was erased from his memory), but the script is Terrible with a capital “T.”

The only person who got a kick out of most of the attempts at comedy in my screening was a guy who was obviously stoned out of his mind, if that tells you anything.

I never thought I’d say this about a movie, but the dialogue also has entirely too much cursing. Profanities are fun when used appropriately, but “American Ultra” sounds like a 12-year-old boy who just discovered cursing and works it into every sentence.

It also doesn’t help that John Leguizamo (playing a conspiracy-theorist drug dealer) says the N-word about 10 times in maybe 15 minutes of screen time.

Stewart becomes a damsel in distress in the final act of the movie, which is annoying because (without spoiling anything) there is a good reason why she should  be able to hold her own in these situations, and she does earlier in the movie.

“American Ultra” gets enough value out of its wacky action sequences and Grace’s shouty, wild-eyed performance to prevent it from being a total disaster. Ultimately, it’s one of those movies that leave you feeling nothing when you walk out of the theater, not even a buzz.