Development of a bedside pain assessment kit for the classification of patients with osteoarthritis.

There are no standardized bedside assessments for subtyping patients with osteoarthritis (OA) based on pain mechanisms. Thus, we developed a bedside sensory testing kit (BSTK) to classify OA patients based on sensory profiles potentially indicative of pain mechanism. After usability and informal reliability testing (n = 22), the kit was tested in a formal reliability study (n = 20). Patients completed questionnaires and sensory testing: pressure algometry to detect hyperalgesia; repeat algometry after heterotopic noxious conditioning stimulation to measure diffuse noxious inhibitory control (DNIC); light touch using Von Frey filaments; and cold allodynia using a brass rod. The procedure was brief and well tolerated. Algometry and filament testing were highly reliable [intra-class correlation coefficients (ICCs) 0.71-0.91]; DNIC was acceptably reliable (ICCs 0.53-0.91); brass rod reliability was inconclusive. Patients were classified empirically into four groups: "All abnormal findings" (primary and secondary hyperalgesia and dysfunctional DNIC); "all normal findings"; and two intermediate groups. The "all abnormal findings" group had more neuropathic pain symptoms, and lower WOMAC total, stiffness, and activity scores than the "all normal findings" group. Simple BSTK procedures, consolidated in a kit, reliably classified OA patients into subgroups based on sensory profile, suggesting that OA patients differ in underlying pain mechanisms. Further research is needed to confirm these subgroups and determine their validity in predicting response to treatment.

Determining the clinically important difference in visual analog scale scores in abuse liability studies evaluating novel opioid formulations.

PURPOSE: This study determined how the magnitude of change in positive subjective responses predicts clinical outcome in a treatment setting. Specifically, we attempted to define what constitutes a clinically important difference (CID) in subjective responses. METHODS: A 100-mm visual analog scale (VAS) measured subjective ratings of drug "high," calculated via an anchor-based method with published data from participants receiving sustained-release naltrexone (NTX) and heroin in a laboratory setting. The data were then compared to clinical outcomes in a treatment trial with sustained-release naltrexone. A distribution-based method subsequently analyzed data from participants who received ALO-01 (extended-release morphine with sequestered NTX) to predict its abuse liability. RESULTS: Differences in ratings of drug high of approximately 10 mm on a 100-mm line were clinically significant. By extrapolation, CIDs were also found between crushed or intact ALO-01 and immediate-release morphine sulfate (IRMS). No CIDs were found between intact and crushed ALO-01. CONCLUSIONS: From laboratory and treatment trial data involving naltrexone, calculation of CIDs in subjective ratings of high is possible. Consequently, crushing/swallowing or injecting ALO-01 produces clinically significantly less drug high than oral or intravenous morphine alone, suggesting that ALO-01 has lower abuse liability by those routes than morphine formulations.

A brief survey to characterize oxycodone abuse patterns in adolescents enrolled in two substance abuse recovery high schools.

BACKGROUND: Although oxycodone is one of the most widely available and abused opioids, little published information exists on the abuse of immediate-release oxycodone. OBJECTIVE: To obtain information on abuse of oxycodone and the effectiveness of abuse-deterrent strategies, especially for immediate-release oxycodone, we surveyed oxycodone abuse patterns in a population of experienced opioid abusers. METHODS: Students or recent graduates of two substance abuse recovery high schools in Massachusetts were surveyed on abuse behaviors with short-acting single-entity oxycodone (e.g., Roxicodone), short-acting combination oxycodone (e.g., Percocet), and extended-release oxycodone. RESULTS: Twenty-four students completed surveys. Mean age was 17.7 years (range 16-19), and mean age at first abuse of oxycodone was 15 (range 13-18). Overall, 56% of students reported oxycodone as their favorite prescription opioid to abuse. The primary preferred method of abuse of all oxycodone formulations was intranasal administration: 83% of single-entity oxycodone abusers preferred intranasal administration compared with 67% of combination oxycodone abusers and 69% of extended-release oxycodone abusers. Approximately half of our respondents preferred to ingest oxycodone orally, 25-38% of respondents swallowed the pill intact, and another 13-17% chewed the pill before swallowing. Maximum dose ever abused at one time ranged from 15 to 400 mg. Most respondents had abused ≥60 mg of oxycodone at a time. CONCLUSIONS: In this small study, adolescent oxycodone abusers use high quantities of oxycodone at a time, alter routes of administration for not only extended-release but also immediate-release products, and commonly abuse single-entity oxycodone products. Abuse-deterrent formulations may be one strategy for addressing such behaviors.

Development and preliminary validation of the focused analgesia selection test to identify accurate pain reporters.

Clinical trials of analgesics have been plagued with poor assay sensitivity due, in part, to variability in subjects' pain reporting. Herein, we develop and evaluate the focused analgesia selection test (FAST), a method to measure patients' pain reporting skills. Subjects with osteoarthritis of the hip, knee, and/or ankle with pain intensity of ≥3/10 on a 0-10 numerical rating scale were enrolled. Subjects underwent the FAST procedure, which consists of recording subjects' pain reports in response to repeated administration of thermal noxious stimuli of various intensities applied on the arm with the Medoc® Thermal Sensory Analyzer II. Subjects also rated non-noxious stimuli consisting of visual contrast rating. After performing an exercise task, subjects also rated clinical pain and were asked to report whether their pain had increased, decreased, or stayed the same. Overall, 88 subjects were enrolled, and 83 were included in the analyses. FAST's outcomes including the R2, intraclass correlation coefficient (ICC), and coefficient of variation (CoV) indicated that subjects' pain reporting skills were widely distributed. Higher FAST ICC significantly predicted greater changes in clinical pain following exercise (p=0.017), whereas the visual contrast test did not predict postexercise pain. FAST is the first method that measures subjects' pain reporting skills. Using FAST to enrich clinical trials with "good" pain reporters (with high FAST ICC) could increase assay sensitivity. Further evaluation of FAST is ongoing.

Nonmedical Use and Diversion of ADHD Stimulants Among U.S. Adults Ages 18-49: A National Internet Survey.

OBJECTIVE: Evaluate nonmedical use (NMU) of ADHD prescription stimulants (Ritalin(®), Adderall(®), Adderall(®) XR, Concerta(®), and Vyvanse(®)) in a U.S. adult general population sample. METHOD: In all, 10,000 adults (aged 18-49) from an online, opt-in panel, proximity matched to U.S. Census demographics, were surveyed to assess NMU prevalence, routes of administration (ROA), reasons for NMU, and diversion source. RESULTS: Lifetime NMU of any prescription drug was 35.1%, pain medications (24.6%), sedatives/tranquilizers (15.6%), sleep medications (9.9%), and prescription stimulants (8.1%). Within the prescription stimulants, rates of NMU (per 100,000 prescriptions dispensed) were 1.62 for Ritalin and 1.61 for Adderall followed by Adderall XR (0.62), Concerta (0.19), and Vyvanse (0.13). Respondents used stimulants mostly for wakefulness and performance enhancement, obtained the drugs from family/friends, and used oral ROA. CONCLUSION: NMU of ADHD prescription stimulants were low compared with other prescription medications. While prevalence of NMU was higher for immediate-release than extended-release ADHD medications, absolute rates for prescription stimulants were low.