Extreme Pharmacology: How Crank Out-Sciences Batman Begins
Films have a history of playing fast and loose with medical and scientific principles. Filmmakers (and maybe more often, the studios) don’t hold their audience in particularly high regard, and as a result, the science in movies is often simplified to the point of being worthless. On many other occasions, filmmakers simply make up whatever they want as long as it fits the plot points. This is especially true when it comes to pharmacology, the study of how drugs interact with the body. Needless to say, the numbers of films with really good science are few and far between. And at this point, I’ve largely gotten over wanting to dislike a film simply because the science is bad (I’ve been told by a few lawyer friends that they do the same with movies that have terrible law in them).
So when I sat down to watch a low-budget action film a few weeks ago, I didn’t have high expectations for the film in general, much less its scientific basis. When I got done, however, I was floored. Not by how good the film was (though both my wife and I enjoyed it), but by the fact that the film’s pharmacology was not only plausible, but probable. And after being reminded about (and re-watching) a big-budget film that has terrible pharmacology, I decided to review both of the films from a scientific perspective, showing both the good and the bad.
Opening on Labor Day weekend of 2006, first time directors Mark Neveldine and Brian Taylor’s frantic action film Crank opened in the midst of a number of varied films. With minimal expectations, the film did solid business, cashing in with over 40 million dollars grossed worldwide and receiving reasonably good reviews.
Crank is as an outlandish exercise that is worthy of its tagline: Poison in his veins. Vengeance in his heart. The story revolves around an LA-based hit man named Chev Chelios (deadpanned to perfection by Jason Stratham). He wakes up feeling terrible, and finds out that he’s been injected with a drug called the ‘Beijing Cocktail’ that will kill him. This is explained to him in the first five minutes of the film by rival gangster Ricky Verona (Jose Pablo Cantillo), who performed the drug injection. As he tells Chelios:
I don’t exactly know what the fuck is in this shit, dude. All I know is that once this shit has binded with your blood cells, you’re fucked baby. And believe me, it’s done binded.
This makes for an exceedingly pissed-off Chelios, who vows revenge and tears off in search of Verona. In the earliest scenes, he discovers a few things that help him via trial-and-error; specifically that pushing himself (driving dangerously, getting in a fight) and taking uppers (first try is cocaine) help him to feel a little better. As writer/director Brian Taylor told me1, one aspect of the film they had in mind was the desire for Chelios not to know what was going on, but to figure out the rules and deal with the situation.
Eventually, Chelios gets a hold of Doc Miles (country star Dwight Yoakam), who’s not the kind of doctor you find in the phone book. Doc knows his stuff however, enough to nail the somewhat unusual diagnosis over the phone, while Chelios runs from the police:
Doc: Symptoms?
Chelios: It’s like I’m slowing down, trapped in a tar pit.
Doc: Blurred vision?
Chelios: Yeah.
Doc: Dizzy?
Chelios: Sure.
Doc: Any pain in your chest?
Chelios (as he crashes through a mall’s glass doors): Not really. Feeling pretty good right now.
Doc: (pause) What are you doing?
Chelios: Driving through a mall, cops chasing me.
Doc: The flow of adrenaline’s what’s keeping you alive.
Chelios: Explain.
Doc: If I’m not mistaken, they gave you the Beijing Cocktail. It works on the adrenal gland, blocks its receptors. The only thing you can do to slow it down at all is to keep the flow of adrenaline constant. If you stop, you die.
And thus, the movie begins in earnest. As you might imagine, Chelios tries all sorts of things to keep his adrenaline levels up: drinking high-energy drinks, rocking out to country music (can you guess the song?), all while still simultaneously looking for Verona and waiting for Doc Miles to get back in town to try to help him.
Adrenal gland? Adrenaline receptors? Mysterious heart ailments? This seems like a good time to take a pause in the action of Crank in order to talk about the sympathetic nervous system and its control of heart function.2
The sympathetic nervous system is one branch of the autonomic nervous system (ANS), and its activation results in functions referred to as ‘fight-or-flight’. Thus, sympathetic nervous system activation induces a host of physiological changes that allow the organism to be prepared for situations requiring strenuous activity, such as exercise, escape behaviors, and sexual activity. The key behavioral outputs for Crank include tachycardia (increased heart rate) and increased blood pressure through vascular constriction. Blood flow is shunted away from the skin and the intestines and is increased in skeletal muscle and the lungs. Finally, activation of sympathetic nerves results in constriction of the genitalia in males, resulting in erection, a medical fact you just know a movie like this won’t neglect.
The neurotransmitters used in the sympathetic nervous system are norepinephrine and epinephrine, with the major peripheral site of release being a gland called the adrenal medulla, located just above the kidneys. In context of the movie, it’s worth noting that adrenaline is simply a synonym of epinephrine, the natural substrate found in the body. Ephedrine, which will come up in a minute, is an artificial epinephrine that is derived from a number of plants. Ephedrine is similar in structure to methamphetamine, a stimulant that is a fairly common drug of abuse.
There are a number of controls on cardiac output, but the largest excitatory inputs are from sympathetic nerves and epinephrine liberated from the adrenal medulla, and they affect the heart in two ways. Adrenaline binding to its receptor family, the adrenergic receptors, increases the ventricular strength of contraction and causes the contraction and relaxation periods to become shorter. This results in more blood entering the ventricle and having that increased blood ejected out of the heart at a great frequency: higher blood pressure, and higher heart rate.