Heminevrin (chlormethiazole liquid-containing capsules 192mg) was generally the drug of choice for alcohol withdrawal in the UK the 1970s. At St. Augustine's, it was rarely, if ever, used for anything else, and was seen as a bit of a wonder drug. It is a sedative, one that predated the benzodiazepines by several decades. Its action, in fact, is closer to the barbiturates, and, like them, it is now recognised as being addictive, with a side-effect profile that has meant it is not a first-line choice for anything, but, of course, it is still manufactured, sold and dispensed fairly widely. With a risk of respiratory depression, chlormethiazole is dangerous in overdose, including among its victims Keith Moon of The Who, who died of a recreational clormethiazole overdose.
For detoxification, it was prescribed with reducing dosage over five days, followed by a smaller maintenance dose; usually four capsules, four times per day on day one, reducing by one capsule per dose on each subsequent day.
In the USA, Librium (chlordiazepoxide tablets 5, 10, 25mg) was generally the drug of choice, for alcohol detoxification, also prescribed in a reducing regimen.
While few studies have directly compared the two drugs in use, those few have generally found that they are equally effective, but chlordiazepoxide is generally considered safer: fewer side effects, safer in overdose, with respiratory depression reversable by flumazenil*. Chlordiazepoxide is now the first line treatment on both sides of the Atlantic (and much of Europe).
The reducing dosage is considered essential, partly because of the sedative effects of the drugs, with a cumulative effect increasing over a few days, but also because many of the recipients have reduced liver function, resulting in overdosage being a real risk: detoxification should take place in a hospital setting, with drug dosage reduced for those with poorer liver function.
It's worth saying, that student nurses of the early 1970s saw the admiration for chlormethiazole, but weren't aware that prior to its widespread use, alcohol detoxification involved the use of drugs such as barbiturates, chloral hydrate or paraldehyde. Chlormethiazole was probably a big advance seen through the yes of 'old timers' and doctors.
Chlordiazepoxide, a benzodiazepine, was widely used for all sorts of indications in the 1970s, though diazepam was probably the first choice benzodiazepine; interestingly, these days, chlordiazepoxide, now in capsule form, is the more popular of the two, with history suggesting that diazepam is much more addictive.
*Duncan, D., Taylor, D. Chlormethiazole or chlordiazepoxide in alcohol detoxification Psychiatric Bulletin (1996), 20, 599-601
09 February 2025
