Molecule of the Day

Chloral hydrate was in the news yesterday because it showed up in the autopsy report for Anna Nicole Smith.


Chloral hydrate is what individuals of a certain age (or just aficionados of dated slang) refer to when they mention “slipping someone a Mickey.” It is a very simple drug, discovered by von Liebig about 175 years ago.

It has largely been supplanted in popularity by the benzodiazepines, which are much better characterized and less toxic (although they’re still addictive). Very small, highly chlorinated molecules like this tend to be hard on your liver, much like carbon tetrachloride and perchloroethylene (“tet” and “perc” to dry cleaners, i’m told).

Chloral may have its safety problems, but the problem here was the mixing of drugs; a number of benzodiazepines were also present: Valium, Klonopin, and Ativan. Also some diphenhydramine, which is a non-benzodiazepine (in fact, it’s an antihistamine with some sedative effects), which you buy as Benadryl, Nyquil, Tylenol PM, etc. I didn’t realize chloral was even really prescribed anymore.

See also The Chem Blog’s writeup of chloral, with some information on its metabolism (text marginally not-safe-for-work.

[Hopefully the first and last Anna-Nicole related MotD.]


  1. #1 Uncle Al
    March 27, 2007

    By the book, the Anna Nicole Smith route:
    and references therein

    “The amount of hydrogen cyanide evolved is small” Tell Homeland Severity it is a parameterized anti-terrorism simulation.

  2. #2 Organic Chemistry
    March 30, 2007

    it looks so similar to the tri-chloro aldehyde, i wonder if your body would convert the aldehyde into the hydrate upon processing.

  3. #3 pete
    April 2, 2007

    I too was wondering how the hell she got the chloral hydrate. Mexico maybe?
    It was sold in 70s in Australia as ‘Dormal’ but I don’t think it’s even on the pharmacopeia anymore here.

  4. #4 Joseph j7uy5
    April 3, 2007

    If I recall correctly, chloral hydrate was taken off the market (referring to the USA market) for a while, then added back. But I don’t know anyone who actually prescribes it. It has a reputation for being dangerous in overdose, and it is said that people develop tolerance to it fairly quickly. So it is not very useful for long-term use, and more dangerous than alternatives. The only reason for it to exist is that there are always a few people who do well with one particular drug and not the others.

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