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Patient reported postoperative pain with a smartphone application: A proof of concept.

Thirty patients (60%) found it satisfying or very satisfying to communicate their pain with the app. Pain experienced after surgery was scored by patients as 'no': 3 (6%), 'little': 5 (10%), 'bearable': 25 (50%), 'considerable': 13 (26%) and 'severe': 1 (2%). Forty-five patients (90%) were positive about the ease of recording. Forty-five patients (90%) could correctly record their pain with the app. Thirty-eight patients (76%) agreed that in-app notifications to record pain were useful. Two patients (4%) were too ill to use the application. Based on usability feedback, we will redesign the pain intensity wheel and the in-app pain chart to improve clarity for patients to understand the course of their pain.

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Illicit opioid use following changes in opioids prescribed for chronic non-cancer pain.

After decades of increased opioid pain reliever prescribing, providers are rapidly reducing prescribing. We hypothesized that reduced access to prescribed opioid pain relievers among patients previously reliant upon opioid pain relievers would result in increased illicit opioid use.

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The Effect of Granisetron on Sensory Detection and Pain Thresholds in Facial Skin of Healthy Young Males.

The specific serotonin type 3 (5-HT)-receptor antagonist granisetron effectively reduces clinical as well as experimental muscle pain and hyperalgesia and with a duration that exceeds that of lidocaine. Hence, it may be an alternative to lidocaine as a local anesthetic. There are also some indications that granisetron in addition to 5-HT receptors blocks sodium channels. Thus, the local anesthetic effect by granisetron may resemble that of lidocaine, but this has not been tested. The aim of this study was therefore to compare the effect granisetron has on facial skin sensitivity to the effect of lidocaine and isotonic saline. This was a randomized, controlled, and double-blind study, in which 1 ml of either granisetron (test-substance), lidocaine (positive control), or isotonic saline (negative control) was injected into the skin over the masseter muscle at three different occasions in 18 healthy males (27.2 ± 5.8 years old). Skin detection thresholds and pain thresholds for thermal stimuli as well as mechanical detection thresholds and sensitivity to a painful mechanical (pinprick) stimulus were assessed before (baseline) and 5, 20, 40, and 60 min after injection. The quality and area of subjective sensory change over the cheek were assessed 20 min after injection. All substances increased the mechanical detection threshold (granisetron: = 0.011; lidocaine: = 0.016; saline: = 0.031). Both granisetron and lidocaine, but not isotonic saline, increased the heat detection thresholds ( < 0.001 and < 0.02, respectively), but not the cold detection thresholds. Granisetron and lidocaine also reduced pinprick pain ( = 0.001 for each comparison). There were no significant differences between granisetron and lidocaine for any of these variables. There was no effect on thermal pain thresholds for any substance. The similar analgesic patterns on mechanical sensory and pain thresholds as well as thermal sensory thresholds over the facial skin by subcutaneous injection of granisetron and lidocaine shown in this study and the absence of paresthesia, in combination with the reduced pain intensity and pressure pain sensitivity shown in previous studies, indicate that granisetron might be a novel candidate as a local anesthetic.

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Insomnia and caregiver burden in chronic pain patients: A cross-sectional clinical study.

Insomnia is a major comorbid symptom of chronic pain and is likely to affect caregiver burden. This cross-sectional study investigated the association between insomnia in chronic pain patients and family caregiver burden. Participants were 60 patients with chronic pain of ≥3 months duration. Demographic and clinical information were collected using the Athens Insomnia Scale (AIS), the Pain Disability Assessment Scale (PDAS), the Hospital Anxiety and Depression Scale (HADS), and a pain intensity numerical rating scale (NRS). Family members who accompanied chronic pain patients to hospital completed the Zarit Burden Interview (ZBI). Univariate regression analysis and multiple regression analysis were conducted to clarify the associations between ZBI scores and total/subscale AIS scores. Covariates were age; sex; pain duration; and scores on the PDAS, HADS anxiety subscale, HADS depression subscale, and NRS. Insomnia was independently associated with ZBI scores [β: 0.27, 95% confidence interval (CI): 0.07-0.52, p = 0.001]. Scores on the AIS subscale of physical and mental functioning during the day were significantly associated with ZBI scores (β: 0.32, 95% CI: 0.05-0.59, p = 0.007). In conclusion, the findings suggest that in chronic pain patients, comorbid insomnia and physical and mental daytime functioning is associated with family caregiver burden independently of pain duration, pain-related disability, and pain intensity.

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Perceptions and Impact of the 2017 Canadian Guideline for Opioid Therapy and Chronic Noncancer Pain: A Cross-Sectional Study of Canadian Physicians.

Physician adherence to guideline recommendations for the use of opioids to manage chronic pain is often limited.

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Validity and Reliability of Itch Assessment Scales for Chronic Pruritus in Adults: A Prospective Multicenter Study.

Several tools can provide a reliable and accurate evaluation of pruritus, including the visual analogue scale (VAS), numeric rating scale (NRS), verbal rating scale (VRS), and multidimensional questionnaires such as the itch severity scale (ISS). However, no single method is considered a gold standard.

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Predicting treatment adherence and outcome to outpatient multimodal rehabilitation in chronic low back pain.

There is a growing need to identify patient pre-treatment characteristics that could predict adherence and outcome following specific interventions.

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The spectrum of response to erenumab in patients with chronic migraine and subgroup analysis of patients achieving ≥50%, ≥75%, and 100% response.

To assess the efficacy of erenumab across the spectrum of response thresholds (≥50%, ≥75%, 100%) based on monthly migraine days (MMD) reduction in patients with chronic migraine from a 12-week, randomized study (NCT02066415).

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Generalization of instrumentally acquired pain-related avoidance to novel but similar movements using a robotic arm-reaching paradigm.

Avoidance is considered a key contributor to the development and maintenance of chronic pain disability, likely through its excessive generalization. This study investigated whether acquired avoidance behavior generalizes to novel but similar movements. Using a robotic arm, participants moved their arm from a starting to a target location via one of three possible movement trajectories. For the Experimental Group, the shortest, easiest trajectory was always paired with pain (T1 = 100% reinforcement/no resistance and deviation). Pain could be partly or completely avoided by choosing increasingly effortful movements (T2 = 50% reinforcement, moderate resistance/deviation; T3 = 0% reinforcement, strongest resistance/largest deviation). A Yoked Group received the same number of painful stimuli irrespective of their own behavior. Outcomes were self-reported fear of movement-related pain, pain-expectancy, avoidance behavior, (maximal deviation from the shortest trajectory), and trajectory choice behavior. We tested generalization to three novel trajectories (G1-3) positioned next to the acquisition trajectories. Whereas acquired fear of movement-related pain and pain-expectancy generalized in the Experimental Group, avoidance behavior did not, suggesting that threat beliefs and high-cost avoidance may not be directly related. The lack of avoidance generalization may be due to a perceived context-switch in the configurations of the acquisition and the generalization phases.

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Evaluation of the Pharmacokinetic Interaction Between the Voltage- and Use-Dependent Nav1.7 Channel Blocker Vixotrigine and Carbamazepine in Healthy Volunteers.

Vixotrigine is a voltage- and use-dependent Nav1.7 channel blocker under investigation for the treatment of peripheral neuropathic pain conditions, including trigeminal neuralgia. Vixotrigine is metabolized primarily via uridine diphosphate-glucuronosyltransferases (UGTs). Carbamazepine, a UGT and cytochrome P450 3A4 inducer, is a first-line treatment for trigeminal neuralgia. We conducted a double-blind, randomized, placebo-controlled, parallel-group, single-center phase 1 study to investigate the impact of coadministering vixotrigine and carbamazepine on their respective pharmacokinetics (PK) in healthy volunteers, the safety and tolerability of combined treatment, and PK recovery of vixotrigine following carbamazepine discontinuation. Randomly assigned treatments were carbamazepine (100 mg twice a day, days 1-3 and 200 mg twice a day, days 4-21) or placebo on days 1 to 21. All volunteers received vixotrigine 150 mg 3 times a day on days 16 to 28. At prespecified times, whole-blood samples were collected for PK assessment. Statistical analyses were performed on the log-transformed PK parameters area under the concentration-time curve within a dosing interval (AUC ) and maximum observed concentration (C ) for vixotrigine, carbamazepine, and metabolites. Vixotrigine AUC and C were reduced by 31.6% and 26.3%, respectively, when coadministered with carbamazepine compared with placebo. Seven days after carbamazepine discontinuation, vixotrigine AUC and C remained 24.5% and 21.4% lower compared with placebo. Carbamazepine AUC and C were <10% lower when coadministered with vixotrigine compared on days 15 and 21. Vixotrigine/carbamazepine coadministration was well tolerated. These results suggest that vixotrigine does not have an effect on carbamazepine PK, and although carbamazepine has an effect on the exposure of vixotrigine, the effect is not considered clinically relevant.

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