Over-the-Counter Relief from Pains and Pleasures Alike: Acetaminophen Blunts Sensitivity to Both Negative and Positive Reactions

Social and Behavioral Sciences; Social Work; Law: 2nd Place (The Ohio State University Edward F. Hayes Graduate Research Forum)Acetaminophen, an effective and popular over-the-counter pain reliever (e.g., Tylenol®), has recently been shown to blunt individuals’ reactivity to a range of negative stimuli beyond physical pain. Because past psychological and neuroimaging research has linked reduced sensitivity to negative reactions to similarly diminished sensitivity to positive reactions, we conducted two experiments testing whether acetaminophen might blunt individuals’ evaluations and emotional experiences to both negative and positive stimuli alike. In each study, participants received either acetaminophen or placebo, and evaluated emotionally evocative stimuli on valence (Study 1 and 2), emotional arousal (Study 1 and 2), and non-evaluative aspects (Study 2). Results revealed that participants taking acetaminophen (versus placebo) evaluated unpleasant stimuli less negatively and pleasant stimuli less positively, and were less emotionally aroused overall. Conversely, non-evaluative judgments were unaffected by treatment. These findings suggest that the mechanism by which acetaminophen reduces pain may more broadly blunt individuals’ evaluative and emotional processing.A one-year embargo was granted for this item

The Effect of Acetaminophen on Conformity

Why do certain individuals feel the pressure of social influence, and thus conform to their peers, more than others? Normative conformity postulates that it is due to individuals’ fears of being deviant from the group. Consistent with this hypothesis, neuroimaging studies have shown that greater conformity is associated with activity in brain areas that are involved in processing the emotional pain of social rejection. Since the physical pain-killer acetaminophen reduces activation in these brain areas as well as reduces hurt feeling associated with rejection, we sought to determine if acetaminophen also reduced conformity. If acetaminophen can reduce social pain, can it also lessen the submission to social pressure? This hypothesis was tested using a between-subjects design that compares the performance of an acetaminophen (test) group to the placebo (control) group on a commonly used social influence task (Berns et al., 2005). Participants are presented with two 3D shapes and asked to determine whether they are mirror images of each other or the same image merely rotated. Then, they are presented with the decision of their “peers” and asked again what kind of transformation is related between the two shapes. Although there were no significant differences in conformity between groups in the rotation judgment condition, there was a significant difference in the preference condition and several significant correlations within the survey data. There were no significant differences in conformity between the placebo and drug condition. A secondary hypothesis was to explore the degree to which collectivism, a psychological construct related to rejection sensitivity, was related to conformity. A significant positive correlation between dispositional sensitivity to rejection and collectivistic orientation was found.No embargoAcademic Major: Neuroscienc

The effects of diclofenac suppository and intravenous acetaminophen and their combination on the severity of postoperative pain in patients undergoing spinal anaesthesia during cesarean section

Introduction: The main tasks of postoperative care are postoperative pain and complications control which play an important role in accelerating the recovery of patient’s general condition. Aim: This study was performed in order to compare the effects of diclofenac suppository, intravenous acetaminophen and their combination on the severity of postoperative pain in patients undergoing spinal anaesthesia for cesarean section in Sayyad Shirazi teaching Hospital, Gorgon, Iran. Materials and Methods: This was a double-blind clinical trial on 90 patients undergoing cesarean section. The patients were randomly divided into three groups, group A: 100 mg diclofenac suppository, group B: 1000 mg intravenous acetaminophen, group C: 100 mg diclofenac suppository and 500 mg intravenous acetaminophen. The same spinal anaesthesia circumstances were applied for all the participants. At the end of surgery, pain severity was assessed according to VAS scale at different times. Data were then analysed by SPSS 18 statistical software. Results: The mean age of participants was (28.27±6.07). There was significant difference between the mean pain scores of the three groups before the intervention (p=0.018), which was considered as co-variate. This difference was more notable between the combination of acetaminophen - diclofenac group and diclofenac alone. After the intervention, significant difference was observed in mean pain severity between acetaminophen group and the combination group and also between diclofenac and the combination group. During the study, the least mean pain severity was found in the combination group and the highest was observed in the diclofenac group. Conclusion: Results of this study indicates a significant effect of concomitant use of intravenous acetaminophen and diclofenac suppository on pain severity reduction and reducing the need for repeated doses of narcotics and prolonging the postoperative analgesia. © 2016, Journal of Clinical and Diagnostic Research. All rights reserved

Does acetaminophen activate endogenous pain inhibition in chronic fatigue syndrome/fibromyalgia and rheumatoid arthritis? : a double-blind randomized controlled cross-over trial

Background: Although enhanced temporal summation (TS) and conditioned pain modulation (CPM), as characteristic for central sensitization, has been proved to be impaired in different chronic pain populations, the exact nature is still unknown. Objectives: We examined differences in TS and CPM in 2 chronic pain populations, patients with both chronic fatigue syndrome (CFS) and comorbid fibromyalgia (FM) and patients with rheumatoid arthritis (RA), and in sedentary, healthy controls, and evaluated whether activation of serotonergic descending pathways by acetaminophen improves central pain processing. Study Design: Double-blind randomized controlled trial with cross-over design. Methods: Fifty-three women (19 CFS/FM patients, 16 RA patients, and 18 healthy women) were randomly allocated to the experimental group (1 g acetaminophen) or the placebo group (1 g dextrose). Participants underwent an assessment of endogenous pain inhibition, consisting of an evaluation of temporal summation with and without conditioned pain modulation (CPM). Seven days later groups were crossed-over. Patients and assessors were blinded for the allocation. Results: After intake of acetaminophen, pain thresholds increased slightly in CFS/FM patients, and decreased in the RA and the control group. Temporal summation was reduced in the 3 groups and CPM at the shoulder was better overall, however only statistically significant for the RA group. Healthy controls showed improved CPM for both finger and shoulder after acetaminophen, although not significant. Limitations: The influence of acetaminophen on pain processing is inconsistent, especially in the patient groups examined. Conclusion: This is the first study comparing the influence of acetaminophen on central pain processing in healthy controls and patients with CFS/FM and RA. It seems that CFS/ FM patients present more central pain processing abnormalities than RA patients, and that acetaminophen may have a limited positive effect on central pain inhibition, but other contributors have to be identified and evaluated

Curing Sinus Headaches and Tying Law: An Empirical Analysis of Bundling Decongestants and Pain Relievers

We apply and extend the cost-based approach to bundling and tying under competition developed in Evans and Salinger (2004) to over-the-counter pain relievers and cold medicines. We document that consumers pay much less for tablets with multiple ingredients than they would if they bought tablets with each ingredient separately. We then decompose the sources of these savings into marginal cost savings and a component that reflects fixed costs of product offerings. The analysis both documents substantial economies of bundling and illustrates the sort of cost analysis that is necessary for understanding tying.

Acetaminophen Does Not Alter the Early Processing of Emotional Facial Expressions: An Eye-tracking Study

A growing body of research has uncovered that acetaminophen, the most commonly used over-the-counter painkilling drug in the United States, produces a number of unintended psychological effects. In particular, recent studies show that acetaminophen blunts a variety of adaptive affective and cognitive processes, including our sensitivity to painful social experiences and subjective responses to emotional stimuli. Using a double-blind placebo-controlled study, here we examined whether acetaminophen alters the early visual processing of emotional facial expressions. Participants consumed 1000 mg of acetaminophen, or a matched placebo, prior to performing a delayed disengagement task with different facial expressions. Specifically, we used eye-tracking software to assess the latency to look away from neutral, happy, and angry faces. Based on prior research, we hypothesized that acetaminophen would reduce the typical delay in disengaging from emotional expressions. Our findings showed a significant main effect of facial expression, with happy faces producing the greatest delay, but there was no difference in response between the acetaminophen and placebo conditions. These results indicate that acetaminophen does not alter our initial assessment of emotional facial expressions, but we suggest further research be conducted to examine how this widely consumed drug may alter the detection and perception of emotions in others

The Effects of Acetaminophen on Neural Indicators of Emotional Reactions

Acetaminophen, the active ingredient in Tylenol, is a popular over-the-counter pain reliever. Recent studies suggest that acetaminophen blunts not only physical pain but also emotional pain (DeWall et al., 2010; Durso, Luttrell, & Way, 2015). The current experiment expands previous research beyond self-report measures to study the effects of acetaminophen administration on emotional responding at the neural level. This study was conducted with a sample of undergraduates from Texas A&M University (n = 97). Participants viewed positive, negative and neutral images on a computer screen while their brain activity was monitored using electroencephalography (EEG). Participants were randomly assigned to either the acetaminophen condition or the control (placebo) condition. On the basis of previous research, we predicted that participants who ingested acetaminophen would have less intense emotional reactions to the negative stimuli as revealed by the late positive potential (LPP, an event-related potential derived from EEG), compared to those who ingested placebo. Personality questionnaires, including the behavioral inhibition and behavioral activation scales (BIS/ BAS; Carver & White, 1994), were included to explore moderating effects. We quantified the LPP as the mean EEG activity in the time window 500-1000 ms after picture onset, separately for each picture type. Results revealed a main effect of picture type, such that positive and negative images elicited larger LPPs than neutral images. However, there was no effect of pill condition and no interaction between pill condition and picture type. This finding is not consistent with our hypothesis or Durso et al.’s self-reported emotion results. We explored moderating effects of BIS on the LPP. A regression analysis found that BIS predicted LPP magnitudes in the placebo condition, but this relationship disappeared in the acetaminophen condition. Within-cell correlations revealed that acetaminophen disrupts the relationship between BIS and LPP for both positive and negative images. These results suggest that trait BIS moderates the effects of acetaminophen on a neural measure of emotional responding

Diclofenac solution (Pennsaid) in the management of osteoarthritis of the knee : Patient implications

Topical diclofenac sodium (pennsaid) is a non-steroidal-anti- inflammatory drug that is used to manage the recurrent pain and symptoms of osteoarthritis of the knee. Pennsaid is applied topically, absorbed cutaneously and concentrates locally at the site of application. Tugwell et al. [54] has shown that pennsaid is as efficacious as oral diclofenac as a mode of pain relief without systemic effects. The most common side effect induced by pennsaid is the development of dry skin at the site of application. This is caused by dimethyl sulfoxide which is the vehicle used in the pennsaid formulation. Dimethyl sulfoxide dissolves the natural oils in the skin causing dryness

Confronting the opioid crisis: Practical pain management and strategies: AOA 2018 critical issues symposium

The United States is in the midst of an opioid crisis. Clinicians have been part of the problem because of overprescribing of narcotics for perioperative pain management. Clinicians need to understand the pathophysiology and science of addiction to improve perioperative management of pain for their patients. Multiple modalities for pain management exist that decrease the use of narcotics. Physical strategies, cognitive strategies, and multimodal medication can all provide improved pain relief and decrease the use of narcotics. National medical societies are developing clinical practice guidelines for pain management that incorporate multimodal strategies and multimodal medication. Changes to policy that improve provider education, access to naloxone, and treatment for addiction can decrease narcotic misuse and the risk of addiction