Predictors of opioid misuse in patients with chronic pain: a prospective cohort study
ABSTRACT Opioid misuse can complicate chronic pain management, and the non-medical use of opioids is a growing public health problem. The incidence and risk factors for opioid misuse in patients with chronic pain, however, have not been well characterized. We conducted a prospective cohort study to determine the one-year incidence and predictors of opioid misuse among patients enrolled in a chronic pain disease management program within an academic internal medicine practice.
One-hundred and ninety-six opioid-treated patients with chronic, non-cancer pain of at least three months duration were monitored for opioid misuse at pre-defined intervals. Opioid misuse was defined as: 1. Negative urine toxicological screen (UTS) for prescribed opioids; 2. UTS positive for opioids or controlled substances not prescribed by our practice; 3. Evidence of procurement of opioids from multiple providers; 4. Diversion of opioids; 5. Prescription forgery; or 6. Stimulants (cocaine or amphetamines) on UTS.
The mean patient age was 52 years, 55% were male, and 75% were white. Sixty-two of 196 (32%) patients committed opioid misuse. Detection of cocaine or amphetamines on UTS was the most common form of misuse (40.3% of misusers). In bivariate analysis, misusers were more likely than non-misusers to be younger (48 years vs 54 years, p < 0.001), male (59.6% vs. 38%; p = 0.023), have past alcohol abuse (44% vs 23%; p = 0.004), past cocaine abuse (68% vs 21%; p < 0.001), or have a previous drug or DUI conviction (40% vs 11%; p < 0.001%). In multivariate analyses, age, past cocaine abuse (OR, 4.3), drug or DUI conviction (OR, 2.6), and a past alcohol abuse (OR, 2.6) persisted as predictors of misuse. Race, income, education, depression score, disability score, pain score, and literacy were not associated with misuse. No relationship between pain scores and misuse emerged.
Opioid misuse occurred frequently in chronic pain patients in a pain management program within an academic primary care practice. Patients with a history of alcohol or cocaine abuse and alcohol or drug related convictions should be carefully evaluated and followed for signs of misuse if opioids are prescribed. Structured monitoring for opioid misuse can potentially ensure the appropriate use of opioids in chronic pain management and mitigate adverse public health effects of diversion.
SourceAvailable from: Srinivas Nalamachu[Show abstract] [Hide abstract]
ABSTRACT: To evaluate the long-term safety, tolerability, and effectiveness of single-entity extended-release hydrocodone in opioid-experienced subjects with moderate to severe chronic pain not receiving adequate pain relief or experiencing intolerable side effects from their current opioid. This multicenter, open-label study started with a conversion/titration phase (≤6 weeks) where subjects (n=638) were converted to individualized doses (range 20-300 mg) of extended-release hydrocodone dosed every 12 hours, followed by a 48-week maintenance phase (n=424). The primary objective (safety and tolerability) and the secondary objective (long-term efficacy as measured by change in average pain score; 0= no pain, 10= worst imaginable pain) were monitored throughout the study. Subjects were treated for a range of chronic pain etiologies, including osteoarthritis, low back pain, and neuropathic and musculoskeletal conditions. The mean hydrocodone equivalent dose at screening was 68.9±62.2 mg/day and increased to 139.5±81.7 mg/day at the start of the maintenance phase. Unlimited dose adjustments were permitted at the investigator's discretion during the maintenance phase, reflecting typical clinical practice. No unexpected safety issues were reported. Common adverse events during the conversion/titration and maintenance phases, respectively, were constipation (11.3% and 12.5%), nausea (10.7% and 9.9%), vomiting (4.1% and 9.7%), and somnolence (7.7% and 4.2%). Four deaths occurred during the study; all were considered unrelated to treatment. One subject died 13 months after the study ended. From the start to end of the conversion/titration phase, 84% of subjects had a clinically meaningful improvement in average pain score (≥30% improvement), and the mean average pain scores remained stable through the maintenance phase. This single-entity, extended-release formulation of hydrocodone was generally safe, well tolerated, and effective in reducing chronic pain for 48 weeks. This formulation provides a new option for patients experiencing chronic pain, especially those who are taking immediate-release hydrocodone and have concerns about liver toxicity due to acetaminophen.Journal of Pain Research 01/2014; 7:669-678. DOI:10.2147/JPR.S71536
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ABSTRACT: Opioid use in chronic pain treatment is complex, as patients may derive both benefit and harm. Identification of individuals currently using opioids in a problematic way is important given the substantial recent increases in prescription rates and consequent increases in morbidity and mortality. The present review provides updated and expanded information regarding rates of problematic opioid use in chronic. Because previous reviews have indicated substantial variability in this literature, several steps were taken to enhance precision and utility. First, problematic use was coded using explicitly defined terms, referring to different patterns of use (ie, misuse, abuse, and addiction). Second, average prevalence rates were calculated and weighted by sample size and study quality. Third, the influence of differences in study methodology was examined. In total, data from 38 studies were included. Rates of problematic use were quite broad, ranging from ,1% to 81% across studies. Across most calculations, rates of misuse averaged between 21% and 29% (range, 95% confidence interval [CI]: 13%-38%). Rates of addiction averaged between 8% and 12% (range, 95% CI: 3%-17%). Abuse was reported in only a single study. Only 1 difference emerged when study methods were examined, where rates of addiction were lower in studies that identified prevalence assessment as a primary, rather than secondary, objective. Although significant variability remains in this literature, this review provides guidance regarding possible average rates of opioid misuse and addiction and also highlights areas in need of further clarification.Pain 04/2015; 156(4):569-576. DOI:10.1097/01.j.pain.0000460357.01998.f1 · 5.84 Impact Factor
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ABSTRACT: Medication assisted treatment for opioid dependence alters the pain experience. This study will evaluate changes pain sensitivity and tolerance with opioid treatments; and duration of this effect after treatment cessation. 120 Individuals with chronic pain were recruited in 4 groups (N=30): 1-methadone for opioid addiction; 2-buprenorphine for opioid addiction; 3-history of opioid maintenance treatment for opioid addiction but with prolonged abstinence (M=121 weeks; SD=23.3); and 4-opioid naïve controls. Participants completed a psychological assessment and a cold water task including, time to first pain (sensitivity) and time to stopping the pain task (tolerance). Data analysis used survival analyses. A Kaplan-Meier-Cox survival analysis showed group differences for both pain sensitivity (log rank=15.50; p<.001) and tolerance (log rank=20.11; p<.001). Current or historical use of opioid maintenance resulted in differing pain sensitivity compared to opioid naïve (p's<.01). However, tolerance to pain was better among those with a history of opioid maintenance compared to active methadone patients (p<.05), with the highest tolerance found among opioid naïve control group participants (p's<.001). Correlations within the prolonged abstinent group indicated pain tolerance was significantly improved as length of opioid abstinence increased (R=.37; p<.05); but duration of abstinence did not alter sensitivity (ns). Among individuals with a history of prolonged opioid maintenance, there appears to be long-term differences in pain sensitivity that do not resolve with discontinuation of opioid maintenance. Although pain sensitivity does not change, pain tolerance does improve after opioid maintenance cessation. Implications for treating co-morbid opioid addiction and pain (acute and chronic) are discussed. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.Drug and Alcohol Dependence 12/2014; 145:143-9. DOI:10.1016/j.drugalcdep.2014.10.010 · 3.28 Impact Factor