The journal of pain : official journal of the American Pain Society
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Comparative Study
Comparison of the risks of opioid abuse or dependence between tapentadol and oxycodone: results from a cohort study.
Tapentadol may have a lower abuse risk than other opioids because it has a relatively low affinity for the mu-opioid receptor. The aim of this retrospective cohort study was to compare the risk of opioid abuse between tapentadol immediate release (IR) and oxycodone IR using 2 claims databases (Optum and MarketScan). Subjects with no recent opioid use exposed to tapentadol IR or oxycodone IR in 2010 were followed for 1 year. The outcome was the proportion of subjects who developed opioid abuse, defined as subjects with International Classification of Diseases, 9th revision, codes for opioid abuse, addiction, or dependence. The relative odds of abuse were estimated using a logistic regression model with propensity-score stratification. The estimates from the 2 databases were pooled using a random effects model. There were 13,814 subjects in Optum (11,378 exposed to oxycodone, 2,436 exposed to tapentadol) and 25,553 in MarketScan (21,728 exposed to oxycodone, 3,825 exposed to tapentadol). The risk of abuse was higher in the oxycodone group than in the tapentadol group in each database. The pooled adjusted estimate for the odds of abuse was 65% lower with tapentadol than with oxycodone (odds ratio = .35, 95% confidence interval = .21-.58). The risk of receiving an abuse diagnosis with tapentadol was lower than the risk with oxycodone. Continued monitoring is warranted because opioid desirability can change over time. ⋯ This study compared the risk of receiving an opioid abuse diagnosis between tapentadol and oxycodone in 2 U.S. claims databases. The risk of receiving an abuse diagnosis was lower with tapentadol during the year of follow-up. Opioid prescribers and patients must be aware of the risk of abuse associated with all opioids.
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This study examined the motives for medical misuse of prescription opioids among adolescents and assessed differences in motives by demographic characteristics, substance abuse, and diversion behaviors. A survey was conducted in 2011 to 2012 and the sample consisted of 2,964 adolescents (51% female). Thirteen percent reported past-year medical use of prescription opioids. Among those prescribed opioids in the past year (n = 393), 17.9% reported medical misuse (eg, using too much, using to get high, or using to increase alcohol or other drug effects). The most prevalent motives for medical misuse were "to relieve pain" (84.2%) and "to get high" (35.1%). Multivariate analyses indicated that the motives differed by race, and that different motives were associated with different substance abuse and diversion behaviors. The odds of past-year substance abuse among medical misusers motivated by non-pain relief were more than 15 times greater than for nonusers (adjusted odds ratio = 15.2, 95% CI = 6.4-36.2, P < .001). No such differences existed between nonusers and appropriate medical users, or between nonusers and medical misusers motivated by pain relief only. These findings improve our understanding of opioid medication misuse among adolescents and indicate the need for enhanced education about appropriate medical use, pain management, and patient communication with prescribers. ⋯ This article represents the first investigation to examine the motives associated with medical misuse of prescription opioids among adolescents. The results indicate that the majority of medical misuse is associated with pain relief. This information could be used to develop strategies to reduce opioid medication misuse among adolescents.
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Persistent postmastectomy pain (PPMP) is increasingly recognized as a major individual and public health problem. Although previous studies have investigated surgical, medical, and demographic risk factors, in this study we aimed to more clearly elucidate the relationship of psychosocial factors to PPMP. Postmastectomy patients (611) were queried about pain location, severity, and burden 38.3 ± 35.4 months postoperatively. Validated questionnaires for depressive symptoms, anxiety, sleep, perceived stress, emotional stability, somatization, and catastrophizing were administered. Detailed surgical, medical, and treatment information was abstracted from patients' medical records. One third (32.5%) of patients reported PPMP, defined as ≥3/10 pain severity in the breast, axilla, side, or arm, which did not vary according to time since surgery. Multiple regression analysis revealed significant and independent associations between PPMP and psychosocial factors, including catastrophizing, somatization, anxiety, and sleep disturbance. Conversely, treatment-related factors including surgical type, axillary node dissection, surgical complication, recurrence, tumor size, radiation, and chemotherapy were not significantly associated with PPMP. These data confirm previous studies suggesting that PPMP is relatively common and provide new evidence of significant associations between psychosocial characteristics such as catastrophizing with PPMP, regardless of the surgical and medical treatment that patients receive, which may lead to novel strategies in PPMP prevention and treatment. ⋯ This cross-sectional cohort study of 611 postmastectomy patients investigated severity, location, and frequency of pain a mean of 3.2 years after surgery. Significant associations between pain severity and individual psychosocial attributes such as catastrophizing were found, whereas demographic, surgical, medical, and treatment-related factors were not associated with persistent pain.
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Genetic variation in the COMT gene is thought to have clinical implications for pain perception and pain treatment. In the present study, we first evaluated the association between COMT rs4680 and the analgesic response to intrathecal morphine in patients with chronic low back pain to provide confirmation of previously reported positive findings. Next, we assessed the relationship between rs4680 and headache response to triptans in 2 independent cohorts of migraine patients. In patients with chronic low back pain (n = 74), logistic stepwise regression analysis showed that age (odds ratio [OR]: .90, 95% confidence interval [CI]: .85-.96, P = .002) and the presence of the COMT Met allele (vs Val/Val, OR: .21, 95% CI: .04-.98, P = .048) were predictive factors for lower risk of poor analgesic response to intrathecal morphine. Intriguingly, in migraine patients, the COMT rs4680 polymorphism influenced headache response to triptans in the opposite direction. Indeed, in an exploratory cohort of migraine patients without aura (n = 75), homozygous carriers of the COMT 158Met allele were found at increased risk to be poor responders to frovatriptan when compared to homozygous patients for the Val allele (OR: 5.20, 95% CI: 1.25-21.57, P = .023). In the validation cohort of migraine patients treated with triptans other than frovatriptan (n = 123), logistic stepwise regression analysis showed that use of prophylactic medications (OR: .43, 95% CI: .19-.99, P = .048) and COMT Met/Met genotype (vs Val/Val, OR: 4.29, 95% CI: 1.10-16.71, P = .036) were independent risk factors for poor response to triptans. ⋯ This study highlights the importance of COMT rs4680 in influencing the clinical response to drugs used for chronic pain, including opioid analgesics and triptans. These findings also underline a complex relationship between COMT genotypes and pain responder status.
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The default mode network (DMN), a group of brain regions implicated in passive thought processes, has been proposed as a potentially informative neural marker to aid in novel treatment development. However, the DMN's internal connectivity and its temporal relationship (ie, functional network connectivity) with pain-related neural networks in chronic pain conditions is poorly understood, as is the DMN's sensitivity to analgesic effects. The current study assessed how DMN functional connectivity and its temporal association with 3 pain-related networks changed after rectal lidocaine treatment in irritable bowel syndrome patients. Eleven females with irritable bowel syndrome underwent a rectal balloon distension paradigm during functional magnetic resonance imaging in 2 conditions: natural history (ie, baseline) and lidocaine. Results showed increased DMN connectivity with pain-related regions during natural history and increased within-network connectivity of DMN structures under lidocaine. Further, there was a significantly greater lag time between 2 of the pain networks, those involved in cognitive and in affective pain processes, comparing lidocaine to natural history. These findings suggest that 1) DMN plasticity is sensitive to analgesic effects, and 2) reduced pain ratings via analgesia reflect DMN connectivity more similar to pain-free individuals. Findings show potential implications of this network as an approach for understanding clinical pain management techniques. ⋯ This study shows that lidocaine, a peripheral analgesic, significantly altered DMN connectivity and affected its relationship with pain-related networks. These findings suggest that the DMN, which is hypothesized to represent non-goal-oriented activity, is sensitive to analgesic effects and could be useful to understand pain treatment mechanisms.