Treatment of carisoprodol dependence: a case report

A Bitter Taste in Your Heart

The human genome contains ∼29 bitter taste receptors (T2Rs), which are responsible for detecting thousands of bitter ligands, including toxic and aversive compounds. This sentinel function varies between individuals and is underpinned by naturally occurring T2R polymorphisms, which have also been associated with disease. Recent studies have reported the expression of T2Rs and their downstream signaling components within non-gustatory tissues, including the heart. Though the precise role of T2Rs in the heart remains unclear, evidence points toward a role in cardiac contractility and overall vascular tone. In this review, we summarize the extra-oral expression of T2Rs, focusing on evidence for expression in heart; we speculate on the range of potential ligands that may activate them; we define the possible signaling pathways they activate; and we argue that their discovery in heart predicts an, as yet, unappreciated cardiac physiology.

Severe Carisoprodol Withdrawal After a 14-Year Addiction and Acute Overdose

BACKGROUND

Carisoprodol, a centrally acting muscle relaxant with a high abuse potential, has barbiturate-like properties at the GABA-A receptor, leading to central nervous system depression and desired effects. Its tolerance and dependence has been previously demonstrated in an animal model, and withdrawal has been described in several recent case reports. Many cases can be effectively managed with a short course of benzodiazepines or antipsychotic agents. However, abrupt cessation in a patient with a history of long-term and high-dose carisoprodol abuse may result in symptoms that are more difficult for providers to treat.

CASE REPORT

We present a case of a 34-year-old man with a long history of carisoprodol abuse who was found unresponsive after having ingested 7.5 grams of carisoprodol. He was intubated and admitted to the intensive care unit. He was given propofol, dexmedetomidine, fentanyl, ketamine, lorazepam, midazolam, quetiapine, and haloperidol, some at high-dose infusions, before his agitation and ventilator asynchrony could be controlled. His improvement coincided with the addition of carisoprodol and phenobarbital to his treatment regimen. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Trends show increasing emergency department presentations for drug-related disorders and treatment. This case highlights an uncommon case of carisoprodol withdrawal that may be encountered by emergency physicians, and demonstrates that benzodiazepines may not be sufficient to suppress severe withdrawal symptoms. Treatment with carisoprodol and phenobarbital provided additional benefit and can be considered in cases of severe carisoprodol withdrawal.

Carisoprodol: an underrecognized drug of abuse in north India

BACKGROUND

There is limited literature on clinical profile of subjects abusing carisoprodol.

METHODS

Our series of 34 subjects shows that a typical subject was an unmarried, unemployed, urban resident from a nuclear family set up; was a substance abuser before being introduced to carisoprodol by another substance abuser; initiated the use to get a better "kick" and after regular use reported craving and withdrawal symptoms.

RESULTS

The effect of carisoprodol was dose dependent: a majority reported a feeling of general wellbeing on consuming up to three tablets; a hypomanic state with 4-10 tablets and confusion, disorientation and drowsiness with >10 tablets at a time.

CONCLUSION

Thus being an underrecognized drug of abuse, carisoprodol is in need of wider awareness and regulatory measures to prevent its emergence as a greater menace in the future.

Carisoprodol tolerance and precipitated withdrawal

AIMS

Carisoprodol is a muscle relaxant that acts at the GABA(A) receptor. Concerns about the abuse liability of carisoprodol are increasing, but evidence that carisoprodol produces tolerance and a significant withdrawal syndrome has yet to be established. The purpose of the current study was to determine if repeated administration of carisoprodol produces tolerance and withdrawal signs in a mouse model.

METHODS

Carisoprodol (0, 100, 200, 300, or 500 mg/kg bid, i.p.) was administered to Swiss-Webster mice for 4 days and loss-of-righting reflex was measured 20-30 min following each administration. On the fourth day, bemegride (20 mg/kg), flumazenil (20 mg/kg), or vehicle was administered following carisoprodol and withdrawal signs were measured. Separate groups of mice receiving the same treatment regimen and dose range were tested for spontaneous withdrawal at 6, 12 and 24 h after the last dose of carisoprodol.

RESULTS

The righting reflex was dose-dependently impaired following the first administration of carisoprodol. A 75-100% decrease in the magnitude of the impairment occurred over the four days of exposure, indicating the development of tolerance to the carisoprodol-elicited loss-of-righting reflex. Withdrawal signs were not observed within 24h following spontaneous withdrawal; however, bemegride and flumazenil each precipitated withdrawal within 15-30 min of administration.

CONCLUSIONS

Carisoprodol treatment resulted in tolerance and antagonist-precipitated withdrawal, suggesting it may have an addiction potential similar to that of other long-acting benzodiazepine or barbiturate compounds.

Characterizing the subjective and psychomotor effects of carisoprodol in healthy volunteers

Carisoprodol is a centrally acting drug used to relieve skeletal muscle spasms and associated pain in acute musculoskeletal conditions. There is evidence from different sources that this oral muscle relaxant is abused and that it is associated with impairment leading to arrests for "driving under the influence" as well as increased risk of automobile accidents. Its subjective and psychomotor effects in healthy volunteers at therapeutic and supratherapeutic doses have not been well-characterized, and form the basis of this report. Fifteen healthy volunteers (8 males, 7 females) were administered 0, 350, and 700 mg of carisoprodol in separate sessions and for 6h afterwards they completed a battery of tests at fixed time intervals so as to assess the subjective and psychomotor effects of the drug. The supratherapeutic dose, 700 mg, increased visual analog scale ratings of terms that were more reflective of sedation (e.g., "sleepy," "heavy, sluggish feeling") than those of abuse liability, and produced impaired performance on several psychomotor tests. The therapeutic dose, 350 mg, while producing few and mild subjective effects, still produced psychomotor impairment. The fact that the therapeutic dose of carisoprodol produced minimal subjective effects while adversely affecting performance is of concern in that patients prescribed this drug may feel relatively normal and engage in tasks (driving) that could put themselves and others at risk.

Carisoprodol withdrawal after internet purchase

INTRODUCTION

Carisoprodol is a centrally acting muscle relaxant used in the treatment of various musculoskeletal disorders whose main metabolite, meprobamate, is a controlled substance in the United States due to its sedative properties and potential for abuse.

CASE DESCRIPTION

We report a case of a 51-year-old man with cognitive impairment and tremor who developed worsening tremor, anxiety, myoclonus, ataxia, and psychosis on abrupt cessation of carisoprodol. At hospital discharge, his cognitive function significantly improved compared with when he was on carisoprodol.

CONCLUSION

Carisoprodol withdrawal is an important and under-recognized syndrome that should be considered in patients presenting with neurologic symptoms who are taking the medication. Carisoprodol withdrawal can be successfully treated with the use of benzodiazepines, although further studies are needed to identify the most appropriate treatment protocol.

Is the frequency of carisoprodol withdrawal syndrome increasing?

Carisoprodol is a commonly used centrally acting muscle relaxant. A number of case reports have suggested that the drug may have abuse potential, presumably because it is metabolized to the anxiolytic drug, meprobamate, which is a controlled substance at the federal level. Two recent case reports described symptoms of withdrawal after the cessation of carisoprodol. We present two additional cases that support the concept of a withdrawal syndrome with this drug. Symptoms of carisoprodol withdrawal include anxiety, tremulousness, insomnia, jitteriness, muscle twitching, and hallucinations. These symptoms are most likely caused by withdrawal from the meprobamate that accumulates after large amounts of carisoprodol are ingested. Although carisoprodol is not a controlled substance at the federal level, clinicians should be aware of its significant potential for abuse.