New Answers for Old Questions in the Treatment of Severe Infections from Injection Drug Use
Hospitalists are increasingly responsible for the management of infectious consequences of opioid use disorder (OUD), including increasing rates of hospitalization for injection drug use (IDU)-associated infective endocarditis, osteomyelitis, and soft tissue infections. Management of IDU-associated infections poses unique challenges: symptoms of the underlying addiction can interfere with care plans, patients often have difficult psychosocial circumstances in addition to their addiction, and they are often stigmatized by the healthcare system. Although there are few randomized trial data to support one particular approach to management, the literature suggests that successful treatment of IDU-associated infections requires appropriate antimicrobial and surgical interventions in addition to acknowledgment and treatment of the underlying OUD. In this narrative review, the best available evidence is used to answer several of the most commonly encountered questions in the management of IDU-associated infections. These data are used to develop a framework for hospitalists to approach the care of patients with IDU-associated infections.
© 2019 Society of Hospital Medicine
What Is the Best Location for Patients to Receive Antibiotics for Their IDU-Associated Infection?
Antimicrobial treatment for severe IDU-associated infections such as endocarditis and osteomyelitis has traditionally included four- to six-week hospital admissions to complete the entirety of IV therapy. This practice has recently been called into question. Extended hospitalization for patients with IDU-associated infections—often not receiving evidence-based treatment for their addiction—can be a harrowing experience and may be antitherapeutic.15,28 Disposition decisions for patients with IDU-associated infections should involve risk stratification to assess addiction disease activity and take into account inpatient addiction treatment resources and patient preference, culture/availability of skilled nursing facilities (SNFs), and safety of the home environment.29 Some emerging models of care take advantage of long hospitalizations by engaging patients with comprehensive addiction services including substance use group meetings, counseling, and social resources. Another model using OPAT with intensive outpatient follow-up for both addiction and infection treatment showed similar infection outcomes, lower cost, and improved patient satisfaction compared with in-hospital treatment.30 When available, medical respite programs and OPAT-friendly residential addiction programs have shown success and financial savings as well.31,32 Still, many patients would prefer home OPAT, and there is evidence that home OPAT is no less successful than OPAT provided in an SNF.33 Despite this mounting evidence, there remains systemic stigmatization of people with OUD and inequity as many SNFs, and home infusion companies will not provide either MOUD or services to patients with OUD.34
Can Oral Antibiotics Be Used to Treat Severe Infections Due to IDU?
A general principle of infectious diseases is that oral antibiotics should be used whenever possible when presumed to be noninferior to IV alternatives. Accumulating evidence in the infectious disease literature suggests that there is a role for increasing the use of oral antibiotics for serious infections. Two recent pivotal randomized trials have questioned the dogma surrounding the use of IV antibiotics for the management of orthopedic infections and endocarditis. However, these studies included few patients with infections due to IDU.35,36 One study of oral antibiotics specifically in patients with IDU-associated infection showed that an all-oral regimen for the management of IDU-associated right-sided endocarditis was effective and well-tolerated.37 While oral antibiotics decrease the need for long-term hospitalization and OPAT, similar or even more intensive follow-up of these patients is required to ensure an appropriate response to treatment. Oral antibiotics should not be used to simply expedite discharge but instead should be done with careful planning and close follow-up.
When using oral antibiotics for severe infections, attempts should be made to use agents with the highest oral bioavailability, tolerability, and affordability. Antimicrobials with near-complete oral bioavailability include fluoroquinolones, triazoles, oxazolidinones (linezolid and tedizolid), clindamycin, trimethoprim-sulfamethoxazole, doxycycline, metronidazole, cefadroxil, and other select oral cephalosporins. One approach is to complete a short course of inpatient induction therapy with IV antimicrobials followed by consolidation therapy with oral antibiotics. In a study of uncomplicated Staphylococcus aureus bacteremia, a similar approach with initial IV therapy and oral linezolid follow-up treatment was noninferior to all-IV treatment.38 Decisions about the early transition to oral antimicrobials should be made in conjunction with infectious disease specialists where available.
