Antibiotic Stewardship for Older Adults in Ambulatory Care Settings: Addressing an Unmet Challenge

Michael S. Pulia, MD, MS; Sara C. Keller, MD, MPH, MSPH; Christopher J. Crnich, MD, PhD; Robin L.P. Jump, MD, PhD; Thomas T. Yoshikawa, MD


J Am Geriatr Soc. 2020;68(2):244-249. 

In This Article

Abstract and Introduction


Inappropriate antibiotic use is common in older adults (aged >65 y), and they are particularly vulnerable to serious antibiotic-associated adverse effects such as cardiac arrhythmias, delirium, aortic dissection, drug-drug interactions, and Clostridioides difficile. Antibiotic prescribing improvement efforts in older adults have been primarily focused on inpatient and long-term care settings. However, the ambulatory care setting is where the vast majority of antibiotic prescribing to older adults occurs. To help improve the clinical care of older adults, we review drivers of antibiotic prescribing in this population, explore systems aspects of ambulatory care that can create barriers to optimal antibiotic use, discuss existing stewardship interventions, and provide guidance on priority areas for future inquiry.


Inappropriate antibiotic use in healthcare settings is an important driver of antibiotic resistance. The increasing prevalence of multidrug-resistant bacteria represents a global public health crisis, and unnecessary antibiotic prescriptions also pose a direct threat to patient safety due to the risk of adverse drug events (ADEs). The last 2 decades have seen antimicrobial stewardship program implementation in acute and long-term care settings. However, available reports indicate that more than 80% of human antibiotic use and 60% of costs occur in ambulatory care settings.[1–3] Estimates also suggest that at least 30% of ambulatory antibiotic prescriptions among American adults are inappropriate.[4] Consequently, the Centers for Disease Control and Prevention has called for actions to enhance antibiotic stewardship in ambulatory settings.[5]

Most ambulatory care antibiotic stewardship research has focused on either pediatric or younger adult populations.[6] However, from 2014 to 2016, older adults (aged >65 y) had the highest ambulatory care antibiotic prescribing rate of any age group, more than 1100 prescriptions per 1000 persons.[7] Older adults are 1.5 times more likely to receive antibiotics in a given year than younger adults, and in 2014 they received 51.6 million prescriptions for antibiotics.[4,8] In the ambulatory clinic setting, adults 65 years and older receive unnecessary antibiotics at more than 46% of visits involving nonbacterial respiratory tract infections (eg, upper respiratory infection, acute bronchitis, sinusitis, and nonsuppurative otitis media), most of which are broad-spectrum agents.[9,10]

This high rate of inappropriate prescribing is particularly concerning for older adults who are at increased risk for a serious ADEs due to age-related physiologic changes, polypharmacy, and comorbidities.[11] Antibiotics as a class are the third most common cause of ADEs among older adults, and nearly 15% of all emergency department (ED) visits for antibiotic-associated ADEs occur in older adults.[12] Antibiotic dosing errors are more common in older adults, and this population is also at increased risk for neurotoxicity (eg, delirium) related to a variety of antibiotic classes.[13,14] This population is also more likely to develop Clostridioides difficile infection (CDI) and experience adverse outcomes as a result; 80% of CDI deaths occur in patients age 65 years and older.[15]

Specific classes of antibiotics pose increased safety risks for older adults. For instance, the Food and Drug Administration has placed a boxed warning on fluoroquinolone antibiotics that highlights older adults at an elevated risk of serious side effects including tendon rupture, delirium, peripheral neuropathy, blood sugar disturbances, and aortic dissection.[16] Fluoroquinolones also increase the risk of CDI. Yet ciprofloxacin was recently found to be the most commonly prescribed antibiotic in patients age 75 years and older in ambulatory settings.[8] Macrolide antibiotics are commonly prescribed to older adults, associated with an elevated risk of cardiac arrhythmia and death in a predominantly male older adult cohort (average age = 56 y).[17] This relationship was not observed in other cohort studies involving younger adults. Trimethoprim/sulfamethoxazole merits particular close monitoring in older adults given the risk of preexisting renal insufficiency necessitating dose adjustment and the potential for drug-drug interactions causing hyperkalemia (eg, angiotensin-converting enzyme inhibitors) or increased bleeding risk (eg, supratherapeutic warfarin levels).

Understanding the barriers to optimal antibiotic use for older adults in ambulatory settings including drivers of unnecessary and inappropriate prescribing is essential in combating antibiotic resistance and preventing harm. We review aspects of ambulatory care that can create barriers to optimal antibiotic use, discuss existing stewardship interventions, and identify priority areas for future inquiry.