Effectiveness of cyanide capsules

I just came back from seeing Downfall, a German film starring Bruno Ganz, about the last days of Hitler. (Great film; I recommend it.)

The film depicts several characters using glass cyanide capsules to commit suicide, and it’s said that the poison will kill within 1 to 2 seconds. In a particularly moving (and apparently historically accurate) scene, Josef Goebbels’ wife kills her six children by breaking capsules in their mouths after having knocked them out with a sedative. Each child gives a little gasp and exhales its last breath after a second or two.

IANA physician, toxicologist, or pathologist, but I have a hard time imagining by what physical mechanism a poison could possibly kill that fast, when administered orally. Injected, maybe, but by mouth I would assume that even the most lethal poisons would take at least a minute or two to get into the bloodstream and do whatever evil things they’re going to do to the heart, lungs, or CNS.

I’ve been Googling for the last hour, and can’t find anything that would support the notion that cyanide can work this fast. In fact I found one site that said that the LD50 for sodium or potassium cyanide is 100-200 mg/kg. Correct me if I’m wrong, but that means it would take 15 grams to kill 50% of 75kg people. Wheras the little capsules shown held a milliliter or two at most.

Poison capsules are the stuff of spy legend, both fictional and historical, and this particular film seems to have made serious efforts to be very accurate in its details. But I can’t reconcile the factual data I’ve found with the nearly instantaneous effectiveness depicted in this (and many other) films and histories.

So what’s the deal on cyanide capsules? If they really can kill almost instantly, how do they do it? (And no, I’m not suicidal, just curious.) Thanks.

I don’t have any specific cites other than a behind-the-scenes look at the making of season 3 of 24 - I won’t go into why they were discussing it in case you haven’t seen it yet. They said that cyanide pills cause a fairly painful, protracted death that takes several minutes, which jibes with other things I’ve heard. I think the mechanism is something along the lines of preventing the electron transport chain from happening in a person’s mitochondria, which is what makes most of the enery a cell gets from breaking down food molecules, meaning that a person with cyanide poisoning’s actually dying from energy lack. I doubt that could possibly be instantaneous, in that it’d have to get diffused throughout the body and the cells would have to use up their ATP stores before it could actually kill somebody.

http://ash.spaink.net/methods.html

Cyanide (HCN, KCN)

    Dosage:
            50 mg Hydrogen Cyanide gas, 200-300 mg Cyanide salts
            
    Time: 
            seconds for HC, minutes Cs (empty stomach) hours (full s)
            
    Available:
            very difficult to get hold of
            
    Certainty:
            very certain
            
    Notes: 
            It helps to have an empty stomach (since the salts react
            with the stomach acids to form H.C.). A full stomach can
            delay death for up to four hours with the salts.
            Antidotes to cyanide poisoning exist, but they have
            serious side effects. What you can do, is instead of
            taking the salts directly, drop 500mg or so into a strong
            acid, and inhale the fumes. This will be pure Hydrogen
            Cyanide, and you should die in 10 to 20 seconds.
            
            [3]: "Hydrocyanic acid is one of the most poisonous
            substances known; the inhalation of its fumes in high
            concentration will cause almost immediate death. Hydrogen
            cyanide acts by preventing the normal process of tissue
            oxidation and paralyzing the respiratory center in the
            brain. Most of the accidental cases are due to inhaling
            the fumes during a fumigating process. In the pure state
            it kills with great rapidity. Crystalline cyanides, such
            as potassium or sodium cyanide are equally poisonous,
            since they interact with the hydrochloric acid in the
            stomach to liberate hydrocyanic acid. This poison has
            been used for both homicide and suicide; in recent
            history, a number of European political figures carried
            vials of cyanide salt for emergency self-destruction and
            some used them. Death resulted from amounts of only a
            fraction of a gram. A concentration of 1 part in 500 of
            hydrogen cyanide gas is fatal. Allowable working
            concentration in most of the United States is 20 ppm. Two
            and one-half grains of liquid acid has killed. The acid
            acts fatally in about 15 minutes. The cyanide salts kill
            in several hours. The average dose of solution is 0.1 cc.
            
            [1, DGHS talking about KCN]:
            on an empty stomach, take a small glass of cold tap
            water. (Not mineral water nor any sort of juice or soda
            water because of it's acidity). Stir 1 -> 1.5 grammes of
            KCN into the water. More than that causes irritation to
            the throat. Wait 5 minutes to dissolve. It should be
            drunk within several hours. Consciousness will be lost in
            about a minute. Death will follow 15 -> 45 minutes later.

I saw Downfall too, and thought the cyanide ampoules were rather too quick-acting. It appears, though, that they contained HCN (hydrogen cyanide, hydrocyanic acid, prussic acid) as opposed to NaCN or KCN (sodium or potassium cyanide). HCN is a liquid at room temperature (it boils at 26°C), though it has a high vapor pressure. The cyanide ampoules contained a liquid, which was more likely liquid HCN than KCN or NaCN (both solids at room temperature) in solution.

Only HCN is directly lethal. KCN and NaCN are fatal if swallowed, because they react with stomach acid to form HCN, which is the actual poison. Thus, death occurs much more quickly with HCN than with the salts. HCN is lethal at a concentration of 300 ppm in air after a few minutes of exposure; taken orally, 50-60 mg is a lethal dose. (This information and the boiling point is from the Merck Index.) The cyanide ampoules would have contained several times this much.

Cyanide kills by preventing the synthesis of ATP, the molecule used to transport and carry energy in every cell. When this happens to a nerve cell, the nerve stops functioning. A very high dose of HCN might therefore cause unconsciousness after a very short time, though I am not certain that death would result within 1 or 2 seconds, as the poison would need to reach the brain before loss of consciousness would occur. HCN would be absorbed through the mucous membranes of the mouth and nose as well as by inhalation; with a glass capsule, there would presumably be some laceration of the inside of the mouth that would hasten the poison’s effect. Again, unconsciousness would occur rapidly, with death following shortly thereafter, but I do not think death would occur as quickly as it did in the film.

Incidentally, accounts differ about the Goebbels children. Antony Beevor’s Berlin: The Downfall 1945 (published under different names in different countries) says that they were first given morphine injections by Dr. Kunz, and that Dr. Stumpfegger and Magda Goebbels gave the cyanide ampoules. (Downfall shows Stumpfegger giving the morphine in a drink, and Madga Goebbels giving the cyanide herself.) The struggle with Helga, the oldest Goebbels daughter, occurs with the morphine-laced drink in the film and with the cyanide ampoule in the book.

No search done. But I believe that the accounts of death in the gas chambers of California would turn up some “scientific” answers. Supossibily these were the most humane (ie quickess) ways to kill a human. Not neccesarily quick if I recall correctly.

Okay, so it looks like I was wrong in assuming that NaCN or KCN would have been used. I saw references to HCN being a gas, so I thought that couldn’t have been what was in the ampoules.

But I was right that even under ideal (so to speak) circumstances, death would take at least a couple of minutes, and even unconsciousness would take several seconds.

Thanks for tracking down these cites, guys.

I suppose there are a couple of possible reasons for this discrepancy between reality and the depiction. It could be that cynically telling users that death will come in only a second or two makes them more likely to use the capsules than providing the clinical truth: “When it’s time, bite down on this. You’ll experience agonizing pain for several minutes before passing out, and you’ll die in about ten minutes.” After all, by the time they find out that they’ve been lied to, it’ll be a little too late.

From the point of view of the filmmakers in this case, it’s a bit less gruesome to imagine the poor children dying quickly and painlessly in their sleep.

I think he’s got it!

/hijack

That’s the damn website I saw that piano wire thing on (from the “Design your grisly death” thread that I can’t find and I can’t search for 'cause I’m still a guest.) Thanks, good to be reminded where that came from.

/hijack

From Gerald Hurst’s anecdote:

http://yarchive.net/chem/cyanide.html

"The problem is that about 15 percent of the people
cannot smell cyanides at all. It is apparently a genetic
trait. I can smell them, but I have been blacked out
momentarily by a whiff I would not describe as pungent."

So it looks like gaseous cyanide can cause a rapid loss of conciousness, even at non-lethal levels. The site also contains some details on cyanide’s metabolic mechanism. The reference to cigarette smoke is because cyanide gas inhaled through a cigarette allegedly produces a metallic taste in the mouth, although I can’t find a cite for that.

This was the first thing I ever found on the Internet, about 12 years ago, when playing around with gopher searchs.

Thx rfgdxm, I thought I had lost it forever !