The idea that opioids modulate the immune system is not new. By the late 19th century, Cantacuzene, used morphine to suppress cellular immunity and lower the resistance of guinea pigs to bacterial infection. While exogenous opioids mediate immunosuppression, endogenous opiates exert opposite actions. Acute and chronic opioid administration is known to have inhibitory effects on humoral and cellular immune responses including antibody production, natural killer cell activity, cytokine expression, and phagocytic activity. Opiates behave like cytokines, modulating the immune response by interaction with their receptors in the central nervous system and in the periphery. Potential mechanisms by which central opiates modulate peripheral immune functions may involve both the hypothalamic-pituitary-adrenal axis and the autonomic nervous system. The presence of opioid receptors outside the central nervous system is increasingly recognized. Those receptors have been identified not only in peripheral nerves but also in immune inflammatory cells. The immunosuppression mediated by opiates may explain the increased incidence of infection in heroin addicts. Opiates may also promote immunodeficiency virus infection by decreasing the secretion of alpha and beta chemokines (important inhibitory cytokines for the expression of HIV) and at the same time increasing the expression of chemoreceptors CCR5 and CCR3, coreceptors for the virus. The fact that peripheral immunosupression is mediated at least in part by opioid receptors located in the central nervous system and that intrathecally administered opioids do not exert the same immunosuppressive effects may have important clinical implications for those patients receiving long-term opioid therapy for malignant and nonmalignant pain.

ImportanceOpioids are routinely prescribed for postoperative home pain management for most patients in the United States, with limited evidence of the amount needed to be dispensed. Opioid-based treatment often adversely affects recovery. Prescribed opioids increase the risk of chronic opioid use, abuse, and diversion and contribute to the current opioid epidemic.ObjectiveTo evaluate whether after hospital discharge, postsurgical acute pain can be effectively managed with a markedly reduced number of opioid doses.Design, Setting, and ParticipantsIn this case-control cohort study, an ultrarestrictive opioid prescription protocol (UROPP) was designed and implemented from June 26, 2017, through June 30, 2018, at a single tertiary-care comprehensive cancer center. All patients undergoing gynecologic oncology surgery were included. Patients undergoing ambulatory or minimally invasive surgery (laparoscopic or robotic approach) were not prescribed opioids at discharge unless they required more than 5 doses of oral or intravenous opioids while in the hospital. Patients who underwent a laparotomy were provided a 3-day opioid pain medication supply at discharge.Main Outcomes and MeasuresTotal number of opioid pain medications prescribed in the 60-day perioperative period, requests for opioid prescription refills, and postoperative pain scores and complications were evaluated. Factors associated with increased postoperative pain, preoperative and postoperative pain scores, inpatient status, prior opioid use, and all opioid prescriptions within the 60-day perioperative window were monitored among the case patients and compared with those from consecutive control patients treated at the center in the 12 months before the UROPP was implemented.ResultsPatient demographics and procedure characteristics were not statistically different between the 2 cohorts of women (605 cases: mean [SD] age, 56.3 [14.5] years; 626 controls: mean [SD] age, 55.5 [13.9] years). The mean (SD) number of opioid tablets given at discharge after a laparotomy was 43.6 (17.0) before implementation of the UROPP and 12.1 (8.9) after implementation (P < .001). For patients who underwent laparoscopic or robotic surgery, the mean (SD) number of opioid tablets given at discharge was 38.4 (17.4) before implementation of the UROPP and 1.3 (3.7) after implementation (P < .001). After ambulatory surgery, the mean (SD) number of opioid tablets given at discharge was 13.9 (16.6) before implementation of the UROPP and 0.2 (2.1) after implementation (P < .001). The mean (SD) perioperative oral morphine equivalent dose was reduced to 64.3 (207.2) mg from 339.4 (674.4) mg the year prior for all opioid-naive patients (P < .001). The significant reduction in the number of dispensed opioids was not associated with an increase the number of refill requests (104 patients [16.6%] in the pre-UROPP group vs 100 patients [16.5%] in the post-UROPP group; P = .99), the mean (SD) postoperative visit pain scores (1.1 [2.2] for the post-UROPP group vs 1.4 [2.3] for pre-UROPP group; P =...

Background:The safety of performing magnetic resonance imaging (MRI) in patients with spinal cord stimulation (SCS) systems needs to be documented. A prospective in vivo study in patients with SCS, exploring the changes produced by MRI and the associated side effects, was performed.Methods: After ethics committee approval and patient consent, 31 consecutive patients with SCS at different spinal levels requiring a scheduled MRI evaluation were studied during an 18-month period. All MRIs were performed with a 1.5-T clinical use magnet and a specific absorption rate of no more than 0.9 W/kg. Frequency tables were used for the descriptive study, whereas comparative evaluations were made with the chisquare test for qualitative variables and single-factor analysis of variance for quantitative variables.Results: The mean patient age was 49 ؎ 9.5 yr; 67.7% were women (n ‫؍‬ 21), and 32.3% were men (n ‫؍‬ 10). None of the patients experienced hemodynamic, respiratory, or neurologic alterations. Reported changes were as follows: increased temperature in the generator's area (n ‫؍‬ 2, 6.5%); increased in the intensity of the stimulation (n ‫؍‬ 1, 3.2%); impedance greater than 4,000 ⍀ on several of the electrodes in the leads (n ‫؍‬ 1, 3.2%); telemetry not possible (n ‫؍‬ 2, 6.5%). Radiologic evaluation after MRI revealed no spatial displacements of the SCS leads in any case.Conclusion: Under the conditions of the described protocol, MRI in patients with SCS systems resulted in few complications. None of the recorded problems were serious, and in no case were patients harmed or the systems reprogrammed. Maximum patient satisfaction was reported in all cases.

Neuropathic pain often imposes a substantial and unrelenting burden on those individuals who have it; single-agent analgesics typically only reduce pain at best. Worldwide, five sets of treatment recommendations offer insight into managing neuropathic pain, including two European guidelines, one Canadian, one Latin American, and another constructed under the auspices of the International Association for the Study of Pain (IASP). The analgesics common to these guidelines are topical lidocaine, secondary amine tricyclic antidepressants, serotonin and norepinephrine dual reuptake inhibitors, calcium channel α(2)-δ ligands, tramadol, and opioid antagonists. Still, significant knowledge gaps in the treatment of neuropathic pain conditions have hampered the development of algorithms and multimodal approaches. As the evidence base expands, the addition of new comparative trial data will further refine the development of new guidance for clinical management of neuropathic pain. New alternatives for managing neuropathic pain, such as the high-concentration capsaicin patch, will enlarge the treatment armamentarium and potentially impact therapeutic guidelines.