Carisoprodol use and abuse in Norway. A pharmacoepidemiological study.

What is already known about this subject • Carisoprodol was developed to create a drug with less abuse potential than meprobamate. • Case reports have established carisoprodol as a drug of abuse, but no systematic studies have been published about the extent of abuse. What this study adds • A large number of patients used more carisoprodol than recommended. • High use of carisoprodol was associated with high use of benzodiazepines and opiates. • Compared with other medicinal drugs, carisoprodol showed many prescription database signals of being a potential drug of abuse. Aim Carisoprodol was developed to create a drug with less potential for abuse than meprobamate. However, case reports have established carisoprodol as a drug of abuse. This paper explores the extent of potential abuse of this drug in Norway. Methods The Norwegian Prescription Database contains information on prescription drugs dispensed to individuals in Norway. Patients can be followed over time. High levels of carisoprodol use could indicate use for pleasurable effects or development of tolerance. Concomitant use of other potential drugs of abuse was also studied. We studied drug-seeking behaviour by looking at patients who received carisoprodol from many different pharmacies and doctors or from high-prescribing doctors. Carisoprodol was compared with a series of other medicinal drugs with or without known potential for abuse. Results Some 53 889 Norwegian women (2.4%) and 29 824 men (1.3%) ≥18 years old received carisoprodol at least once in 2004. Prescribing of carisoprodol was skewed. As many as 32% of the patients received more than 15 defined daily doses (DDDs) of carisoprodol and >11 000 patients (15%) received ≥75 DDDs in 2004. High users of carisoprodol also received more benzodiazepines and opioids. Few patients used three or more doctors for prescriptions, but carisoprodol-abusing patients more often received their prescription from high-prescribing doctors. Conclusions Carisoprodol was widely used and the skewedness in use indicated that it is a potential drug of abuse. A large number of patients used more carisoprodol than recommended in the guidelines. The high level of use and abuse of carisoprodol should be of concern in Norway. [ABSTRACT FROM AUTHOR]