Pharmacology - good study!!: is Carisoprodol (soma) JUST a prodrug? no.

[Politicalchalk]

Translating Norwegian one imagines, might encounter some challenging difficulties, so if you get confused like I did reading it, try switching around some of the "thing" and "not-thing" occourences. It's basically saying that, while it is a prodrug of mebprobamate, an older and much-abused sedative/hypnotic ( I think it relaxes skeletal muscle, too...it was found sometimes in combination with say aspirin or acetaminophen (APAP)) ...that Carisoprodol unchanged itself has properties which are active, and in fact impairing. It was long thought that, in the same way morphine was the only active agent in codeine (it's not), that the mebprobamate was the only active chemical, even though it's original design was to create a LESS abusable drug BASED on mebprobamate.

"Yes, son: I think that this great land of Miltown is finally going to get on the map!"

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Bramness JG, Skurtveit S, Mørland J. Norwegian Institute of Public Health, Division of Forensic Toxicology and Drug Abuse, Nydalen, 0403 Oslo, Norway. jorgen.bramness@labmed.uio.no
BACKGROUND: Carisoprodol is a centrally acting muscle relaxant commonly used for lower back pain. It is a drug of abuse and has been detected among impaired drivers. Carisoprodol's active metabolite meprobamate is thought to act through the GABA(A) receptor complex and produces a well-known impairing effect. It is unclear whether therapeutic intake of carisoprodol leads to impairment, and the effect of supratherapeutic doses has not been investigated. Possible impairment could further be a product of the parent drug and/or the metabolite meprobamate. The present study aimed to investigate if carisoprodol had an impairing effect by it self. METHODS: From the database at the Norwegian Institute of Public Health, Division for Forensic Toxicology and Drug Abuse 62 cases containing carisoprodol and meprobamate as only drugs were identified. These cases constituted our material. RESULTS: Impaired drivers (73%) had higher blood carisoprodol concentration than not impaired drivers (27%), but no difference in blood meprobamate concentration was found for all the drivers viewed together. Amongst occasional users of carisoprodol, however, there was difference in blood meprobamate concentration between not impaired and impaired drivers. The risk of being judged impaired rose with increasing blood carisoprodol concentration, but not with increasing blood meprobamate concentration. The clinical effects of carisoprodol as measured by the clinical test for impairment (CTI) resembled those of benzodiazepines with some important differences such as tachycardia, involuntary movements, hand tremor and horizontal gaze nystagmus, which may be specific carisoprodol effects. CONCLUSION: Carisoprodol probably has an impairing effect by itself, at least at blood concentration levels above which can be seen after therapeutic intake of the drug.