Codeine Shopping Behavior in a Retrospective Cohort of Chronic Noncancer Pain Patients: Incidence and Risk Factors.

Codeine is a widely used opioid analgesic but studies on its misuse in chronic noncancer pain (CNCP) are still lacking. The aim of this study was to assess the incidence of codeine shopping behavior in CNCP patients and to identify the associated risk factors. This was a population-based retrospective cohort study from the French health insurance claims database from 2004 to 2014. The main outcome was the one-year incidence of codeine shopping behavior defined as ≥1 day of overlapping prescriptions written by ≥2 different prescribers and filled in ≥3 different pharmacies. A total of 1,958 CNCP patients treated with codeine were included, with a mean age of 62.7 ± 16.1 years, 36.8% men. The 1-year incidence rate of codeine shopping behavior was 4.03% (95% confidence interval [CI], 3.07-5.28). In multivariate analysis, risk factors associated with shopping behavior were younger age (≤40 years) (hazard ratio [HR] = 7.29; 95% CI, 4.28-12.42), mental health disorders (HR = 2.25; 95% CI, 1.08-4.67), concurrent use of anxiolytic benzodiazepines (HR = 3.12; 95% CI, 1.55-6.26), and previous use of strong opioids (HR = 2.94; 95% CI, 1.24-6.98). The incidence of codeine shopping behavior in CNCP patients was 4% and risk factors identified were shared with those of opioid abuse. PERSPECTIVE: Shopping behavior for codeine was not infrequent in CNCP patients. The risk factors identified in this study are similar to those identified for opioid abuse in other studies. Appropriate use of codeine from the perspectives of patients and healthcare providers should be encouraged.

Therapeutic drug monitoring and tyrosine kinase inhibitors.

The therapeutic activity of drugs can be optimized by establishing an individualized dosage, based on the measurement of the drug concentration in the serum, particularly if the drugs are characterized by an inter-individual variation in pharmacokinetics that results in an under- or overexposure to treatment. In recent years, several tyrosine kinase inhibitors (TKIs) have been developed to block intracellular signaling pathways in tumor cells. These oral drugs are candidates for therapeutic drug monitoring (TDM) due to their high inter-individual variability for therapeutic and toxic effects. Following a literature search on PubMed, studies on TKIs and their pharmacokinetic characteristics, plasma quantification and inter-individual variability was studied. TDM is commonly used in various medical fields, including cardiology and psychiatry, but is not often applied in oncology. Plasma concentration monitoring has been thoroughly studied for imatinib, in order to evaluate the usefulness of TDM. The measurement of plasma concentration can be performed by various analytical techniques, with liquid chromatography-mass spectrometry being the reference method. This method is currently used to monitor the efficacy and tolerability of imatinib treatments. Although TDM is already being used for imatinib, additional studies are required in order to improve this practice with the inclusion of other TKIs.

Incidence of tramadol shopping behavior in a retrospective cohort of chronic non-cancer pain patients in France.

PURPOSE: Opioid analgesic use in chronic non-cancer pain (CNCP) is increasingly prevalent, but the benefits and risks are inadequately understood. In France, tramadol is one of the most used prescription opioids, but studies on its misuse liability in CNCP are still lacking. The aim was to assess the incidence of tramadol shopping behavior in CNCP patients and to identify the associated risk factors. METHODS: A retrospective cohort of CNCP patients aged 18 years and older treated by tramadol for at least six consecutive months between 2005 and 2013 from a sample of the French Health Insurance database was established. Doctor shopping was defined as at least 1 day of overlapping prescriptions written by two or more different prescribers and filled in at least three different pharmacies. RESULTS: A total of 3505 CNCP patients were included with a majority of women (66.4%) and a mean age of 66.4 ± 14.7 years. The median tramadol treatment duration was 260 [interquartile range: 211-356] days. The 1-year incidence rate of tramadol shopping behavior was 1.0% [95%CI: 0.7-1.5]. On multivariate analysis, risk factors associated with tramadol shopping behavior were age (hazard ratio [HR] = 7.4 [95%CI: 2.8-19.7] for age <40, HR = 2.8 [95%CI: 1.0-7.7] for 40 ≤ age < 50, versus age ≥50), low-income status (HR = 8.5 [95%CI: 3.6-20.5]), and prior use of strong opioids (HR = 5.7 [95%CI: 1.9-17.0]). CONCLUSION: Tramadol shopping behavior incidence appears low in CNCP patients but may represent a public health concern given the widespread use of tramadol. Education and best monitoring of high-risk patients are needed to reduce doctor shopping. Copyright © 2016 John Wiley & Sons, Ltd.

Fully automated semi-quantitative toxicological screening in three biological matrices using turbulent flow chromatography/high resolution mass spectrometry.

BACKGROUND: In clinical and forensic toxicology, fast and specific methods are needed for the screening of different classes of drugs. A complete general unknown screening procedure was developed using turbulent flow chromatography with electrospray ionization and Orbitrap mass spectrometry. METHODS: After protein precipitation, samples were injected directly into the turbulent flow chromatographic system and analyzed with an Orbitrap mass spectrometer. The Exactive® operated in positive and negative modes with alternated high collision dissociation in order to obtain characteristic fragments. We built a library containing 616 compounds by analyzing a reference standard for all the molecules. RESULTS: Identification was based on retention time, accurate measured mass, isotopic pattern and presence of specific fragments. For each substance, we set a calibration range encompassing infra-therapeutic, therapeutic, supra-therapeutic and toxic concentrations in order to generate semi-quantitative result. For 65% of the components, the limit of detection was below 5 ng/mL. The validation process showed the approach to be selective, sensitive, accurate and precise. CONCLUSION: The method has been accredited by COFRAC (French Accreditation Committee) according to the ISO 15189 standard. Applicability was successfully tested by analyzing authentic serum, urine and whole blood samples.