Given the opportunity, and in certain research laboratories they are given the opportunity, monkeys will use cocaine to the exclusion of all else. To the exclusion of eating. To the exclusion of sex. To the exclusion of survival.

They will simply use cocaine until they die.

Such frightening images, from study after medical study, have in the past few years built an ironclad case that cocaine is among the deadliest of recreational drugs.

Now comes "High on the Job" (tonight at 9 on Channel 5) to say it all again.

Actor Stacy Keach, himself a reformed drug user (or "substance abuser," a police term that has regrettably gained popular status), hosts this hour-long rehash of the case against cocaine. While Keach's presence adds a certain intrigue and a sense of moral certitude, it does little to make the show interesting.

Smiling not once, Keach walks us through endless testimonials from former addicts -- including a cardiologist, a plastic surgeon, a former judge (whose electronically disguised voice makes him sound like a Munchkin), a once-wealthy businessman, a nurse and a railroad mechanic -- all of whose lives were in some way sidetracked by the drug.

"I spent money that was not mine," the cardiologist says. "I stole money from my mother. I stole money from my practice."

But for a show that purports to explore drug use of ordinary people in ordinary jobs, there are few such scenes and instead, an awful lot of shots of doctors at work. When we're not watching a doctor at work, it seems, we're digging up coca bushes in Peru.

One has to watch carefully, too, because writer-director-executive producer Christopher Jeans is sometimes careless with the facts in an effort to leave an impression.

At one point, quite suddenly, we are shown an exploded chemical plant (we're not told where), and Keach says: "An investigation turned up no official cause for this chemical-plant explosion, but informed sources cite drug use on the job." Eight seconds, and not another mention.

Sandwiched between scenes about cocaine, there's a $4 million train wreck, which, we are told, by the way, was caused by "alcohol and fatigue."

And then there's the claim that cocaine "could be partly responsible" for the rush on Chicago savings and loans this spring. The connection lies several layers deep in the financial world, and it sounds almost as if even Keach doesn't believe it.

In the scene from Peru, we see soldiers leading an expedition to uproot coca bushes, and Keach says the soldiers look like "John Wayne riding shotgun on the Wells Fargo stagecoach." A Spanish-sounding band provides the background music.

Such silliness and hyperbole detract from the show's strong moments -- the tale of a woman who sold her infant to get cash for cocaine, the pursuit of a drug-smuggling airplane that ends in a fiery crash, the confession from the surgeon that while using cocaine he didn't care about his patients.

Says the cardiologist at one point: "I think it's good for me to keep talking about it."

The trouble is, in the whole long hour, there are only a few nuggets worth listening to.