Posted by tony p on February 26, 2014, at 19:31:27
In reply to Re: meprobamate??, posted by tony p on February 26, 2014, at 14:57:55
The history of meprobamate & related muscle relaxants is interesting. I'm an old-timer now, & was in med/biochem research at the time, so I remember it personally.
The first really effective muscle relaxant was Tolserol / mephenesin & the closely related Tolseram (the carbamate), deveoped in the 1940s. It was extremely effective, but erratically absorbed, had some bad S/E, & was particularly dangerous with alcohol.
Robins (I believe) came up with a "me-too" variation, very similar in structure, Robaxin/methocarbamol. It turned out to be a great improvement over mephenesin: better absorbed, less S/E; although not quite as effective a muscle relaxant, the dosage range is enormous: from 1 - 1.5 gm qid for simple back or neck strain to 12 gm or more for nasty things like tetanus & strychnine poisoning.
When it came off the Rx list & became OTC and then out on the shelves most places (in combinations only) it became a huge seller & must make a mint for the drug companies, as it's been around since at least the 1950s & their research costs were doubtless covered decades ago. It continues to be pricey, even though it's a pretty simple compound to make, I suspect just the marketplace - back pain must be in the top 10 complaints for which people take OTCs.
Meanwhile, other researchers developed meprobamate also based on mephenesin. The chemical structures don't resemble each other much on paper, but presumably the 3D configurations are more closely related. Meprobamate, the first "minor" tranquilizer besides Reserpine, was not only a huge success medically, it became the "in thing" to take socially: see T S Eliot's "The Cocktail Party".
Unfortunately, concerns over addiction led eventually to its abandonment in favour of the supposedly non-addictive benzodiazepines, which (a common story in drug history) then turned out to be a far worse problem in long-term use.
Soma/carisoprodol, structurally almost identical to meprobamate, was developed as a less-addictive muscle-relaxant (starting to sound familiar?). It is really just a pro-drug for meprobamate, which it is metabolized to, acting much like an extended-release formula. Still addictive, but less so because of the slow release.
All of these drugs have virtually vanished in North America behind the juggernaut of the benzo industry (are you still with me?). A great shame IMHO as this whole family of drugs has a quite different mode of action & spectrum of effects from the benzos, and the addiction problem can be managed just as it is for other addictive meds.
As a final note, who was it who said, "Those who do not learn from history are doomed to repeat it"? My late mother, an MD in the early 20th century, remembered when heroin was developed as a -- wait for it -- NON_ADDICTIVE substitute for morphine! Rim-shot please.
poster:tony p
thread:1060897
URL: http://www.dr-bob.org/babble/20140214/msgs/1061402.html