Meprobamate is a carbamate (category of organic compounds that is formally derived from carbamic acid) derivative and is used as an anxiolytic (anxiety-relieving) drug.
Frank Berger, a Czechoslovakian pharmacologist, was working in a laboratory of a British drug company looking for a preservative for penicillin when he noticed that mephenesin (a muscle relaxant that can be used as an antidote for strychnine poisoning) calmed the lab rodents without sedation. He talks about this “tranquilizing” effect in the British Journal of Pharmacology in 1946. There were three drawbacks, short duration of action, greater effect on the spinal cord than on the brain, and a weak activity
In May 1950, at Carter Products in New Jersey, with the help of chemist Bernard John Ludwig, Berger synthesized a chemically related tranquilizing product that overcame these drawbacks, meprobamate.
During a 1955 study at Mississippi State Hospital (asylum) in Whitfield, Mississippi, self-destructive patients became cooperative and calmer and experienced a resumption of logical thinking. In 50% of the cases, relaxation brought about more favorable sleep habits.
…capable of changing the quality of human consciousness.Aldous Huxley (English writer and philosopher of nearly 50 novels and non-fiction books)
By 1956, 1 out of every 20 Americans had used the drug. It was getting lots of publicity from such as entertainer and comedian Milton Berle. Marketed as a mild tranquilizer it earned 40 million dollars by 1960. In 1965 it was removed from the list of tranquilizers and ruled a sedative and disclosed that it could be addictive. In December 1967 it was placed under abuse control amendments to the Food, Drug and Cosmetic Act and required a prescription and refills.
By 1970 meprobamate was listed as a controlled substance after it was discovered to cause physical and psychological dependence. In 2012, the European Medicines Agency withdrew marketing authorization and in 2013 Canada did the same.
Symptoms of meprobamate overdose include drowsiness, headache, sluggishness, unresponsiveness, or coma; loss of muscle control; severe impairment or cessation of breathing; or shock. As little as 12 grams has been known to cause death but some have survived as much as 40 grams, activated charcoal should be considered even after 4 or more hours or if levels are rising. In a recent re-opened cold case of Bruce Lee’s cause of death, it was determined that the probable cause was Equagesic (a brand of Meprobamate that is mixed with aspirin) that caused the acute cerebral edema.