Saul Silver (James Franco, left), Red (Danny McBride, center), and Dale Denton (Seth Rogen) in Pineapple Express.

Columbia Pictures / Dale Robinette

The recent news that Richard Marin and Thomas Chong are going to reunite as Cheech and Chong, again doing their high-on-marijuana act that kept audiences in the 1970s doubled over with drug-induced laughter, shouldn’t come as a surprise to the producers of Pineapple Express.

They know that although drug-related humor has been pretty much on the back burner for several years, it may be time to hit those high notes once again. Or not. The future of movies featuring characters who view the world through a pot-induced haze will hinge on the success of Pineapple Express.

It’s a guys-on-the-run-from-killers comedy, a familiar plot device that has been used over the years by everybody from the Bowery Boys to Abbott and Costello to Bing Crosby and Bob Hope, Dean Martin and Jerry Lewis. The difference here is that the plot has been goosed up by the fact that the clue to the identity of a murder witness is the roach he left at the scene containing a remarkably potent new strain of marijuana called Pineapple Express.

There are wacky car chases, goofy run-ins with the law and with the killers along the way, as well as a perpetual air of silliness which, more often than being a good thing, seems forced. Unless you are watching the film through a haze yourself, you might wonder whether it’s really funny watching James Franco, as a drug dealer who loves his own product, for the 10th time putting himself in danger because the lure of the weed is stronger than the self-preservation run-for-your-life thought. Or whether it’s really funny seeing a seemingly endless fight in which people are punched in the mouth, banged on the head, shot in the stomach, run over by a car.

Pineapple Express bears the hallmarks of producer Judd Apatow (The 40-Year-Old Virgin, Knocked Up, Superbad are some of his) — lots of potty-mouthed humor, a smirking view of sex, pandering to an early 20s audience. Some of the film is quite funny, but it runs too long and often winds up groveling for laughs.

A big plus is Seth Rogen, who was the hapless star of Knocked Up and here again plays a hapless schnook who unwittingly gets himself in big trouble when he witnesses a murder committed by a drug czar (Gary Cole) that sets up a war with a rival Asian drug gang. Rogen and longtime writing partner Evan Goldberg (who wrote Superbad based on a script they started working on as teenagers) came up with the story idea of Pineapple Express with Apatow; Rogen and Goldberg then wrote the finished script which glorifies the immature American male. After all, Rogen’s Dale Denton is a twentysomething guy whose girlfriend is still in high school.

Looking a bit like a 20th-century Albert Brooks, Rogen has that actor’s same “Why Me?” and “I Can’t Believe This Is Happening!” reactions to a myriad of ever-growing calamities. Dale may be a nitwit and a fool, but in his more lucid moments he’s a sage compared to James Franco’s naïve drug dealer, Saul Silver, who has the cultural interests of a 12-year-old and lives somewhere in the late 1960s. Dale, who is a process server, is the perfect foil for Franco’s lame-brained Saul, who only wants to get high and raise enough money to keep his grandmother comfortably ensconced in a rest home.

Their going-nowhere lives are suddenly enlivened and threatened when Dale witnesses the murder and leaves a butt full of Pineapple Express at the scene, a strain of marijuana so new that it’s easily traced back to Saul, the only dealer who so far has been given a supply.

Quickly, the boys are fleeing the drug lord’s henchmen whom he has dispatched in the belief that Dale is in cahoots with the Asian gang. Dale is afraid to go to the cops, because he has seen a policewoman (Rosie Perez) assisting in the murder.

Director David Gordon Green becomes a traffic cop for all the action, though sometimes everything seems to collide at once. Along the way the boys get caught up in a trap sprung by Red (Danny McBride), Saul’s even more-hapless-than-Dale drug middle man; take an outrageously wild ride in a stolen police cruiser with Saul’s foot sticking out of the broken windshield; wreck a dinner party at the home of Dale’s teenage girlfriend; get caught up in a very long and contrived kidnapping that leads to an even more contrived drug war that brings every bad apple in the cast to an elaborate drug warehouse. In the film’s funny black-and-white 1937-era prologue we first see that warehouse, planted underground in a farm field, was designed as a military experiment lab way back when.

In the end the battered Red makes a stronger impression than the hazy wallflower that Franco becomes. McBride is a one-man comic relief, but even the sight of Red’s increasingly broken body threatens to become overkill, as it were. And overkill is the operative term here.

** 1/2Pineapple Express

Starring: Seth Rogen, James Franco, Danny McBride, Gary Cole, Rosie Perez.

Rated: R, contains violence, drugs, profanity.

mjanuson@projo.com