Funded Projects

Oral cancers are painful and often require use of opioid medications to manage pain. However, the effectiveness of opioids often wanes quickly, and many patients require higher doses because they develop tolerance to these medications. This project will study the potential value of blocking epidermal growth-factor receptors interacting with peripheral nerves to treat oral cancer pain. The findings will advance understanding of the molecular mechanisms underlying oral cancer pain and provide a rationale for repurposing epidermal growth-factor receptor blockers, which is already approved for head and neck cancer treatment for treating oral cancer and associated pain.

Interstitial cystitis/bladder pain syndrome is a debilitating disease affecting many women. Opioid-based pain management is a common feature of current treatment approaches but is associated with the risk of addiction. The causes of this disorder remain unknown, and no effective treatments are available. This project will provide new insights using genetic, medication-based and other approaches in a mouse model, along with single-cell gene expression studies conducted with cells from mice and human patients who have this condition. The analyses will help provide targeted, safe, and effective treatment approaches for individuals with interstitial cystitis/bladder pain syndrome.

It is increasingly clear that the microbiome influences psychoneurological symptoms, including pain. This project will support clinical research training focused on examining the relationship between the composition and function of the gut microbiome, including the symbiotic bacteria residing in the gut and their functional gene content, and chronic pain among adults with end-stage kidney disease (ESKD). It provides an opportunity for the trainee to expand his skill set as a pain investigator, through experience in implementing and evaluating pain management interventions in adults with ESKD and chronic pain receiving maintenance hemodialysis. The project aims to determine the acceptability of collecting feces and the feasibility of fecal data collection procedure to determine the best strategies for recruiting research participants from multiple dialysis facilities. These steps will allow the exploration of gene content of the gut microbiota and short-chain fatty acids among people with ESKD on maintenance hemodialysis before and after pain management interventions.

In this study, 600 to 700 hemodialysis patients receiving chronic opioids will be randomized across the Hemodialysis Opioid Prescription Effort (HOPE) Consortium to enhanced treatment as usual, buprenorphine therapy, or buprenorphine plus mindfulness-based cognitive therapy intervention delivered by telephone and adapted for pain (MBCT-TP). The following specific aims will be assessed: Aim 1—to assess the effectiveness of buprenorphine in reducing chronic opioid use and prescriptions in hemodialysis patients on opioids at baseline, compared with an enhanced treatment as usual intervention and to assess the effectiveness of buprenorphine in improving pain intensity, quality of life measures, and hospitalizations; Aim 2—to assess the incremental effectiveness of MBCT-TP added to buprenorphine compared with buprenorphine alone on pain interference with physical, social, and mental functioning, opioid use, pain intensity, other quality of life measures, hospitalizations, and mortality.

Despite the pervasive use of opioid analgesics in the dialysis population and the substantial risks they engender, their efficacy is limited in treating common chronic pain conditions. Most patients receiving long-term opioid therapy continue to experience severe pain and functional limitations. To simultaneously address problems related to chronic pain and opioid use in the U.S. hemodialysis population, this study will evaluate tailored patient-centered interventions to manage pain and reduce opioid use. Patients will be assigned randomly to one of three groups over a 12-month study period: 1) pain care management (PCM) versus 2) PCM plus an online pain self-management program (PSM) that incorporates cognitive behavioral training and is delivered during dialysis sessions, versus 3) control with medication review and education. The study will also evaluate the effectiveness of offering buprenorphine by randomly assigning participants in both active treatment arms to being offered buprenorphine rotation versus continued standard opioid taper support without the option of buprenorphine.

Chronic pancreatitis (CP) and the debilitating pain associated with it remains a common and challenging clinical syndrome that is difficult to treat effectively. Using rodent models of CP, preliminary studies have found that nerve growth factor (NGF) and transforming growth factor beta (TGFb) appear to be acting by the common effector, calcitonin-gene related peptide (CGRP), to induce pain in CP. CGRP is known to mediate pain as a neurotransmitter in the central nervous system, specifically as a potent vasodilator involved in migraine. This project will test the hypothesis that peripheral CGRP is a major mediator of peripheral nociceptive sensitization in CP, and that peripherally restricted anti-CGRP treatment could provide an efficient and sufficient approach for the treatment of pain in pancreatitis

The goal of this project is to generate data and reagents that help uncover critical functions of the poorly characterized members of ion channels. It focuses on co-perturbation of ion channel genes and their interacting genetic components as opposed to singly altering ion channel genes in mouse models. This approach will validate our proteomics approaches in the most definitive manner: in vivo. We see in vivo exploration as an essential step to evaluate ion channel function. Our major aims include mapping ion channel interactions and complexes using a high-throughput proteomics platform at UCSF. These data will be interrogated using integrative approaches established by the Monarch Initiative, where biochemical interactions will be validated and prioritized for further study. Another major aim is function-centric: We use mouse models for elucidation of human disease mechanisms, where we embrace a genetic interaction scheme to uncover ion channel redundancy and polygenic effects.

This study will evaluate novel strategies to reduce opioid use and pain in patients with end-stage renal disease receiving chronic hemodialysis (HD). Specifically, the study will examine the effect of nonpharmacologic (Acceptance and Commitment Therapy [ACT] and acupuncture) and pharmacologic (buprenorphine) interventions in HD patients who are receiving chronic opioid medications due to chronic pain and/or high pain interference. The study will enroll 720 HD patients across U.S. Hemodialysis Opioid Prescription Effort Consortium Clinical Centers to (1) determine the effectiveness of ACT and acupuncture compared with the control condition in reducing opioid dose and improving pain among HD patients; (2) identify the best adaptive intervention sequence for improved outcomes; (3) explore age, sex, and comorbidities as potential moderators of the response to the intervention; and (4) describe facilitators and barriers to the implementation of the intervention using in-depth, semi-structured individual interviews with intervention participants and providers.

Medications have proven to be effective for treating opioid use disorder (OUD). Increasing accessibility to buprenorphine provides an opportunity for many with OUD to benefit from its proven effectiveness. Adherence to medication-based treatments however is low, in part because of the stigma associated with use of this and other effective drugs and as such, leads to inadequate treatment and poor outcomes. This study aims to understand the effects of stigma on patient engagement, retention, and outcomes of buprenorphine treatment. Knowledge drawn from the HIV Stigma Theory and tools developed to reduce HIV associated stigma will be used to assess OUD stigma and to develop interventions to reduce it in the context of buprenorphine treatment. The study findings may provide resources to address stigma and thus maximize treatment adherence among those affected by OUD.

There is an urgent need for non-opioid post-operative pain management solutions.  This research is developing a naturally absorbable polymer film that can release controlled amounts of the non-opioid analgesic bupivacaine – aiming to manage pain for several days following surgery. Project objectives are to optimize the timing of drug release, develop manufacturing standards, determine effective dosage for preserving motor function, and determine safety and efficacy in mouse models of neuropathic pain. Continued development of this film delivery system may lead to a new, non-opioid therapeutic strategy that could be combined with local anesthesia for up to 4 days after surgery to reduce or potentially eliminate opioids use.

African American adults are less likely to receive analgesics, particularly opioids. Research in the pediatric surgical population is limited, but the pattern of disparate use of opioids appears consistent with adults. Furthermore, adolescent access to prescribed opioids has increased, both through physician prescribing and misuse of medications prescribed to family members or friends. This study will explore the interrelated impacts of policy, clinical need, and sociodemographic factors by combining Medicaid claims and electronic health record data with findings from a statewide opioid policy inventory. We will focus on discharge prescribing of opioids in three high-volume pediatric surgical procedures: tonsillectomy/adenoidectomy, supracondylar fracture, and appendectomy. We aim to 1) determine the extent of racial disparities in postoperative discharge opioid prescribing since the 2011 onset of enhanced opioid prescription reduction activities and 2) develop an expanded model to assess the linkage between differential opioid use for pediatric postoperative pain and opioid use-related outcomes.

Ethnic groups show substantial variability in the experience of acute and clinical pain, with African Americans (AAs) having more clinical pain conditions and higher levels of pain severity and pain-related disability compared to non-Hispanic whites (NHW). Ethnic differences in opioid neurotransmitters suggest that these systems function less efficiently among AAs and may account for differences in pain and analgesic responses. The overwhelming majority of clinically used opioids elicit their effects through activation of the mu-opioid receptor, making it a relevant target for investigation. We propose to examine ethnic differences in the supraspinal endogenous opioid system using positron emission tomography (PET) imaging of mu-opioid receptors employing the mu-selective agonist [11C]carfentanil. Healthy AAs and sex-, age-, SES-matched NHW participants will undergo one baseline (non-pain) and one capsaicin-induced pain PET session using [11C]carfentanil. The current proposal will measure µ-opioid binding potential and examine its role in ethnic group differences in pain sensitivity.

Many barriers exist in primary care offices where socioeconomically disadvantaged patients are most often treated. This project seeks to address chronic pain disparities that affect racially diverse, socioeconomically disadvantaged individuals. The study aims to optimize multimodal pain management in primary care clinics for low-income populations. This study includes two group-based models: integrative group medical visits and group acupuncture. These two interventions will be compared to typical treatment to measure both pain interference and social isolation. National experts and patient stakeholders will refine and optimize the design of the study with English- or Spanish-speaking patients with chronic pain in two primary care clinics for low-income populations.