New Answers for Old Questions in the Treatment of Severe Infections from Injection Drug Use

As a result of the epidemic of opioid use disorder (OUD), there has been a secondary surge in hospitalizations for infectious complications of injection drug use (IDU).^1,2 In the previous 10 years, there have been significant increases in IDU-associated human immunodeficiency virus (HIV)³ and hepatitis C virus (HCV)⁴ infection as well as increased hospitalizations from IDU-associated skin and soft tissue infections, osteomyelitis, septic arthritis, bacteremia, fungemia, and infective endocarditis in the United States.^2,5-7 Patients admitted with IDU-associated infections have long lengths of stay, high rates of leaving against medical advice (AMA), readmission, and mortality.^8-13 In a British cohort (median age 36 years), five-year mortality after an episode of IDU-associated endocarditis was 42%.¹⁴ Admissions for IDU-associated infections can be a troubling experience for both patients and providers alike.¹⁵ While management decisions of IDU-associated infectious syndromes have sometimes been based on emotion, dogma, and an often-stigmatizing approach toward people suffering from addiction,¹⁶ with a better understanding of addiction and effective treatments, as well as accumulating data in both addiction and infectious disease fields, it is an appropriate time to reevaluate the approach to treatment.

The goal of this review is to examine recent evidence and attempt to answer questions that frequently arise in the management of hospitalized patients with IDU-associated infections. The questions addressed in this review primarily stem from the discussion of Schranz and colleagues in their description of increasing hospitalizations for IDU-associated endocarditis.⁷ Additionally, questions were developed from discussions with practicing academic hospitalists. For each question, a review of the published literature was performed, with a focus on articles published between 2014 and 2019. Finally, a framework for how to approach patients with infectious complications of IDU is presented. As a comprehensive review of infectious complications of OUD would be difficult to cover in one review, this review will focus on eight questions that frequently arise in the care of inpatients.

How Should OUD Be Managed in the Hospital?

Management of an IDU-associated infection is incomplete without addressing the underlying addiction in some way. Addiction is highly undertreated among patients with IDU-associated infections, which may contribute to poor infection-related outcomes.^8,13,17 Opioid agonist therapy (buprenorphine and methadone) to prevent withdrawal should be routinely offered to all patients with OUD including those with infectious complications of OUD to facilitate appropriate medical treatment and engage patients in long-term addiction treatment. Referral to addiction treatment has been associated with improved IDU-associated endocarditis mortality,¹⁸ and initiation of medications for OUD (MOUD) can be achieved successfully in the emergency department, inpatient wards, and specifically in patients admitted with IDU-associated endocarditis.^19-21 Protocols and resources for inpatient management of withdrawal and initiation of MOUD are available along with telephone support services for providers seeking guidance on specific cases.^21,22 Inpatient addiction consult services are an important resource for the management of hospitalized patients with addiction and are associated with increased completion of antibiotics, decreased AMA discharge, and increased rates of MOUD provision among patients with IDU-associated infections.¹² However, when unavailable, initiation of opioid agonist therapy does not require an addiction specialist. Linkage to outpatient addiction care is ideal; however, opioid agonist therapy initiated in the hospital can be tapered prior to discharge if this is unavailable. Figure 1 outlines the initiation of methadone or buprenorphine for the treatment of both withdrawal and OUD in the inpatient setting.^20,21