Paxton Bach

University of British Columbia - Vancouver | UBC · Department of Medicine

Objectives: To examine the relationship between benzodiazepine (BZD) use and HCV seroconversion in 2 linked prospective cohorts of persons who inject drugs (PWID). Methods: We examined prospective cohorts of 440 PWID (baseline BZD users: n = 102; 23.2%) from the AIDS Care Cohort to Evaluate Access to Survival Services (ACCESS) and the Vancouver...

Background: Although methadone is an effective treatment for opioid use disorder, its initiation requires prescribing at a subtherapeutic dose with subsequent titration to a therapeutic dose over many weeks. Accordingly, the methadone induction period can be a challenging one for individuals and can be associated with an increased risk for ongoing...

The global rise in opioid-related harms has impacted the United States severely. Current efforts to manage the opioid crisis have prompted a re-evaluation of many of the existing roles in the healthcare system, in order to maximize their individual effects on reducing opioid-associated morbidity and preventing overdose deaths. As one of the most ac...

An older man was admitted to the hospital for planned bowel resection. He reported drinking 8 to 10 ounces of whiskey daily for many years. During previous hospitalizations, he had no documented alcohol withdrawal symptoms or seizures. His last drink was 3 days prior to admission.

Background Within the United States, there is a shortage of opioid treatment programs (OTPs), facilities which dispense methadone for opioid use disorder. It is unknown how pharmacy-based methadone dispensing, as available internationally, could affect methadone access. We aimed to compare drive times to the nearest OTP with drive times to the near...

In 2018, Canada enacted the Cannabis Act, becoming only the second country (after Uruguay) to legalize the recreational consumption of cannabis. Although there is ongoing global disagreement on the risk-benefit profile of cannabis with increasing legalization in many parts of the world, the evidence of rising cannabis use prevalence postlegalizatio...

Objectives: Despite unregulated amphetamine use increasing, there are limited data on related emergency department (ED) visits in Canada. Our primary objective was to examine trends in amphetamine-related ED visits over time in Ontario, including by age and sex. Secondary objectives were to examine whether patient characteristics were associated w...

Introduction: Conflictual evidence exists regarding the effects of cannabis use on the outcomes of opioid agonist therapy (OAT). In this exploratory analysis, we examined the effect of recent cannabis use on opioid use, craving, and withdrawal symptoms, in individuals participating in a trial comparing flexible buprenorphine/naloxone (BUP/NX) take...

Objective: Unregulated stimulant use is rising globally, though trends in use of cocaine and crystal methamphetamine (CM), the two most commonly used unregulated stimulants in North America, are poorly characterized in many settings. In this study we examined patterns and associations between the injection of cocaine and CM over time in an urban C...

Background: Patient satisfaction is key to the success of methadone maintenance treatment (MMT), and yet how MMT satisfaction is affected by the increasingly common use of crystal methamphetamine among people receiving opioid treatment remains poorly understood. We aimed to assess the association between crystal methamphetamine use and MMT dissati...

We present the case of a young man with acute-onset chest and back pain to the emergency department with what was initially thought to be a myocardial infarction complicated by mixed respiratory failure. However, several days into the admission, the patient disclosed using a substance known as “kratom,” a novel psychoactive substance with mu-opioid...

Background: Crystal methamphetamine use has substantially increased among people who use opioids in recent years, yet the impact of opioid agonist therapy (OAT) on crystal methamphetamine use remains poorly characterized. Therefore, we sought to examine the relationship between OAT engagement and crystal methamphetamine use and to assess if this r...

Introduction: The emergence of COVID-19 introduced a dual public health emergency in British Columbia, which was already in the fourth year of its opioid-related overdose crisis. The public health response to COVID-19 must explicitly consider the unique needs of, and impacts on, communities experiencing marginalisation including people with opioid...

Objectives: Although amphetamine use is a growing health problem in the USA, there are limited data on amphetamine-related hospitalisations. The primary objective of our study was to examine trends in amphetamine-related hospitalisations in the USA between 2003 and 2014, including by age and sex. Our secondary objectives were to examine whether de...

Background In the context of the ongoing opioid crisis in the United States and Canada, opioid agonist therapy (OAT) is the first-line treatment for opioid use disorder. However, there is growing concern regarding the increasing methamphetamine use among those on OAT, as well as the impact of such use may have on OAT retention and outcomes. We soug...

Background: We aimed to determine medications' comparative efficacy and safety for adults with alcohol use disorders. Methods: We searched eleven electronic data sources for randomized clinical trials with at least 4 weeks of treatment reporting on alcohol consumption (total abstinence and reduced heavy drinking), dropouts, and dropouts due to a...

Background Buprenorphine-naloxone (BUP-NX) is a first-line treatment for opioid use disorder and has a superior safety profile compared to other forms of opioid agonist therapy. In Canada, restrictions on BUP-NX prescribing were relaxed in 2016, which may have had an effect on rates of diversion and non-prescribed use. We sought to longitudinally e...

Background and aim: There have been few head-to-head clinical trials of pharmacotherapies for alcohol withdrawal (AW). We therefore aimed to evaluate the comparative performance of pharmacotherapies for AW. Methods: Six databases were searched for randomized clinical trials through November 2021. Trials were included after a blinded review by tw...

Objectives Methamphetamine use is rising globally and we have limited treatments for this. Subgroups within the diverse methamphetamine-using population may have distinct treatment needs. Among a community-recruited sample of people who use crystal methamphetamine, we aimed to identify subgroups and characterize their overdose risk and access to ad...

Background We describe addiction consult services (ACS) adaptations implemented during the Novel Coronavirus Disease 2019 (COVID-19) pandemic across four different North American sites: St. Paul’s Hospital in Vancouver, British Columbia; Oregon Health & Sciences University in Portland, Oregon; Boston Medical Center in Boston, Massachusetts; and Yal...

An amendment to this paper has been published and can be accessed via the original article.

Background: Individuals with severe and persistent mental illness (SPMI) have a higher risk of contracting COVID-19 than individuals without SPMI. In combination with physical distancing, hygiene protocols, and vaccines, quarantine and self-isolation are primary means of viral containment. However, individuals with SPMI may experience more difficu...

Importance Methadone access may be uniquely vulnerable to disruption during COVID-19, and even short delays in access are associated with decreased medication initiation and increased illicit opioid use and overdose death. Relative to Canada, US methadone provision is more restricted and limited to specialized opioid treatment programs. Objective...

Background: The efficacy of methadone in reducing morbidity and mortality associated with opioid use disorder is supported by a wealth of evidence, yet methadone retention is often poor. While crystal methamphetamine (methamphetamine) use has been recently increasing in many countries, the effect of frequency of methamphetamine use on methadone di...

In Reply We thank Sechi and Sechi for their interest in our recent article describing challenges in the diagnosis and management of alcohol withdrawal in medically ill hospitalized patients.¹ We certainly agree that Wernicke encephalopathy (WE) should always be included in the differential diagnosis for delirium in patients with a history of heavy...

Introduction Methamphetamine use is increasing in North America and is associated with numerous negative health effects and social harms. As drug‐related harms are often gendered, this study sought to examine the differential impacts of gender on the trends, risk factors and health implications of crystal methamphetamine use among a Canadian cohort...

Amidst the opioid overdose crisis, there are increased efforts to expand access to medications for opioid use disorder (MOUD). Hospitalization for the complications of substance use in the United States (US) provides an opportunity to initiate methadone, buprenorphine, and extended release naltrexone and link high-risk, not otherwise engaged, patie...

Background: Illicit stimulants such as crystal methamphetamine and cocaine are a rising cause of morbidity and mortality in North America. Unfortunately, there are few evidence-based approaches for the management of stimulant use disorder. Contingency management programs are currently the best evidenced treatment strategy, designed to reward behav...

Background North America is facing an unprecedented public health crisis of opioid-related morbidity and mortality, increasingly as a result of the introduction of illicitly manufactured fentanyl into the street drug market. Although the treatment of opioid use disorder (OUD) is a key element in the response to the opioid overdose epidemic, current...

We present here the case of an 81-year-old female with a history of giant cell arteritis whose presenting complaint was nonspecific lower abdominal pain. Her symptoms had been previously unresponsive to antibiotics for presumed diverticulitis, as well as escalating doses of empiric steroids for possible vasculitis. She underwent a computed tomograp...

In the midst of an opioid epidemic, mortality related to opioid overdose continues to rise in the US. Medications to treat opioid use disorder, including methadone and buprenorphine, are highly effective in reducing the morbidity and mortality related to illicit opioid use. Despite the efficacy of these life-saving medications, the majority of peop...

Plasmodium falciparum is the most common causative agent of severe malaria infections. Following inoculation, the incubation period typically ranges from 10 to 14 days, and, unlike other malaria species, there is no hypnozoite phase in the life cycle capable of causing latency. Despite this, we now understand that subclinical P. falciparum infectio...

Objective: Illicit drug use is a well-established risk factor for increased morbidity and mortality. However, little is known about the impact of benzodiazepine use on mortality among populations of polysubstance users. This study aimed to identify the effect of benzodiazepine use on mortality among a prospective cohort of people in Canada who inj...

Background: Methadone maintenance therapy (MMT) is a proven treatment strategy for opioid dependent patients. Although studies have demonstrated that MMT increases contact with the medical system and improves adherence to antiretroviral therapy (ART) in HIV-positive people who inject drugs (PWID), the effect of MMT discontinuation on ART discontin...

Methadone maintenance therapy (MMT) is an evidence-based treatment for opioid addiction. While gender differences in MMT pharmacokinetics, drug use patterns and clinical profiles have been previously described, few studies have compared rates of MMT use among community-recruited samples of persons who inject drugs (PWID). The present study used pro...

Despite barriers to its use in many settings, opioid agonist therapy with methadone has become the standard of care for treating opioid (e.g. heroin) use disorder. Since people with opioid use disorders have an increased incidence of incarceration, we undertook the present study to evaluate the association between incarceration and methadone mainte...

This study set out to explore the current state of global health concentrations in Canadian medical schools and to solicit feedback on the barriers and challenges to implementing rigorous global health concentration programs. A set of consensus guidelines for global health concentrations was drafted through consultation with student and faculty lea...

BACKGROUND Interferon-gamma release assays (IGRAs) may be useful in diagnosing latent tuberculous infection (LTBI) in inmates; however, published experience in these settings is limited. OBJECTIVE To identify variables associated with IGRA positivity among Canadian federal inmates with positive tuberculin skin test (TST) results. DESIGNOn intake, T...

Prenatal alcohol exposure (PAE) has adverse effects on the development of numerous physiological systems, including the hypothalamic-pituitary-adrenal (HPA) axis and the immune system. HPA hyper-responsiveness and impairments in immune competence have been demonstrated. The present study investigated immune function in PAE females utilizing an adju...

Glial cells, including oligodendrocytes, astrocytes and microglia are important to proper central nervous system (CNS) function. Deregulation or changes to CNS populations of astrocytes and microglia in particular are expected to play a role in many neurodegenerative diseases, including Parkinson's disease, amyotrophic lateral sclerosis (ALS) and A...

1,25-Dihydroxyvitamin D(3) is immunosuppressive both in vivo and in vitro. Topical vitamin D analogs such as calcipotriol alter keratinocyte function, but their effects on cutaneous immune responses are less well understood. We demonstrate that exposure of the skin to calcipotriol before transcutaneous immunization with OVA protein and CpG adjuvant...

Cryptococcus gattii has recently emerged as a primary pathogen of humans and wild and domesticated animals in British Columbia, particularly on Vancouver Island. C. gattii infections are typically infections of the pulmonary and/or the central nervous system, and the incidence of infection in British Columbia is currently the highest reported globa...

Recent Cryptococcus gattii infections in humans and animals without travel history to Vancouver Island, as well as environmental isolations of the organism in other areas of the Pacific Northwest, led to an investigation of potential dispersal mechanisms. Longitudinal analysis of C. gattii presence in trees and soil showed patterns of permanent, in...

1,25-dihydroxyvitamin D3 (Vitamin D) is a potent immunomodulator capable of generating regulatory T cells (Tregs) and contributing to immune tolerance. Additionally, vitamin D has been shown to promote mucosal immunity when used as a vaccine adjuvant. We show here that pretreatment of an area of skin with the synthetic vitamin D analog calcipotriol...