Ther Drug Monit. 1994 Aug;16(4):337-40.
Carisoprodol elimination in humans.

Olsen H, Koppang E, Alvan G, Morland J.

Department of Clinical Pharmacology, University Hospital, Tromso, Norway.

The elimination of the muscle relaxant drug, carisoprodol, was examined in 10 healthy volunteers after an oral dose of 700 mg. In nine subjects, carisoprodol was rapidly eliminated, with a mean half-life of 99 +/- 46 min, and extensively converted to meprobamate. Within 2.5 h after carisoprodol intake, meprobamate serum concentrations exceeded those of carisoprodol. Serum levels of meprobamate recorded (15-25 mumol/L) indicate that meprobamate might contribute to the effect(s) of carisoprodol. One subject eliminated carisoprodol with an overall half-life of 376 min, and only small amounts of meprobamate were recorded. This subject was found to be a poor metabolizer of mephenytoin. In spiked human sera, protein binding of carisoprodol was in the range of 41-67%, whereas meprobamate was bound to a lesser extent, 14-24%.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7974621&dopt=Abstract soma carisoprodol




Arch Fam Med. 1993 Apr;2(4):429-32.
Carisoprodol as a drug of abuse.

Rust GS, Hatch R, Gums JG.

Department of Family Medicine, Morehouse School of Medicine, Atlanta, Ga.

Carisoprodol (available as Soma and in other commercial forms) is a commonly prescribed muscle relaxant. A small group of patients was recently discovered colluding to obtain the drug under false pretenses for the purposes of substance abuse. Animal and human studies have previously shown limited potential for tolerance or abuse, while the evidence for therapeutic efficacy is inadequate. There are two previous case reports of human carisoprodol abuse or dependence, one in which a patient showed signs of a true withdrawal syndrome. A third case involved a fatality linked to carisoprodol abuse. Data from the National Institute on Drug Abuse reveal that overdose and abuse of carisoprodol may be more common than previously suspected. Carisoprodol use should be limited to short-term treatment of acute musculoskeletal conditions involving significant muscle spasm. Suspicions of abuse should be raised by patients requesting the drug by name, "losing" prescriptions, using carisoprodol chronically, or denying the efficacy of less mind-altering alternatives.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8130923&dopt=Abstract soma carisoprodol




Acta Psychiatr Scand. 1993 Oct;88(4):302-3.
Carisoprodol abuse: a report from India.

Sikdar S, Basu D, Malhotra AK, Varma VK, Mattoo SK.

Department of Psychiatry, Postgraduate Institute of Medical Education & Research (PGIMER), Chandigarh, India.

Carisoprodol, a centrally acting muscle relaxant, has recently been noticed to be abused. A series of 16 cases with carisoprodol abuse or dependence is described. Carisoprodol was started by the majority of patients as a substitute for opiates, although its independent distinct effects, similar to the features of hypomania, were recognized and described by most users. The drug is currently available freely over the counter and is a much cheaper substitute for the legally prohibited "harder" drugs. Unless awareness spreads and cautionary measures are taken, carisoprodol abuse might become a great menace in the near future.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8256651&dopt=Abstract soma carisoprodol