Antibiotic use in the elderly: issues and nonissues

National Trends in Oral Antibiotic Prescribing in United States Physician Offices from 2009 to 2016

BACKGROUND

Prior studies have found that outpatient antibiotics are commonly prescribed for non-bacterial conditions. It is unclear if national prescribing has changed in recent years given recent public health and antimicrobial stewardship initiatives. This study aimed to describe antibiotic prescribing in United States (U.S.) physician offices.

MATERIALS/METHODS

This was a cross-sectional study of all sampled patient visits in the Centers for Disease Control and Prevention's National Ambulatory Medical Care Survey from 2009 to 2016. Antibiotic use was defined as at least one oral antibiotic prescription during the visit as identified by Multum code(s). Patient visits were categorized by U.S. geographic region and season. ICD-9-CM and ICD-10 codes were used to assess diagnoses and categorize antibiotic use as appropriate, possibly appropriate, or inappropriate.

RESULTS

Seven billion visits were included for analysis, with 793,415,182 (11.3%) including an antibiotic. Prescribing rates were relatively stable over the study period (102.9-124.9 prescriptions per 1000 visits); however, 2016 had one of the lowest prescribing rates (107.7 per 1000 visits). The most commonly prescribed antibiotic class was macrolides (25 per 1000 visits). The South region and winter season had the highest antibiotic prescribing (118.2 and 129.7 per 1000 visits, respectively). Of patients who received an antibiotic, 55.9%, 35.7%, and 8.4% were classified as inappropriate, possibly appropriate, and appropriate, respectively. The most common conditions in which antibiotics were prescribed inappropriately included those with no indication in any of the predefined diagnosis codes (40.1%), other skin conditions (17.3%), and viral upper respiratory conditions (13.3%).

CONCLUSIONS

There was no significant reduction in outpatient antibiotic prescribing rates among U.S. outpatients from 2009 to 2016 and prescribing varied by region and season. These data suggest that more than half of antibiotics were prescribed inappropriately, with the majority of antibiotics prescribed with no indication. However, these findings need to be confirmed with robust prospective studies.

Pharmacotherapy options and drug development in managing periprosthetic joint infections in the elderly

INTRODUCTION

Prosthetic joint infections are an increasingly important problem among patients undergoing arthroplasty procedures, and are associated with significant morbidity, reduced quality of life, substantial healthcare costs, and even mortality. Arthroplasties are performed with increasing frequency in elderly patients, who present specific problems.

AREAS COVERED

Surgical therapy is clearly influenced by the clinical status of the patient, which in some case can contraindicate surgery. Antibiotic selection is also affected by comorbidities and underlying diseases, which in some cases reduce therapeutic options. The authors review this together with the changes in pharmacokinetics and pharmacodynamics in the elderly population and the prospects for future research on prevention and treatment.

EXPERT OPINION

The management of PJI in the elderly makes multidisciplinary teams even more mandatory than in other patients, because the complexity of these patients. A frequent scenario is that in which surgery is contraindicated with long-term suppressive treatment as the only available option. Treating physicians must consider the presence of multiple comorbidities, interactions with other treatments and secondary effects when choosing antibiotic treatment. An in-depth knowledge of the alterations in pharmacokinetics and pharmacodynamics in elderly patients is key for a proper treatment selection.

Sepsis: multiple abnormalities, heterogeneous responses, and evolving understanding

Sepsis represents the host's systemic inflammatory response to a severe infection. It causes substantial human morbidity resulting in hundreds of thousands of deaths each year. Despite decades of intense research, the basic mechanisms still remain elusive. In either experimental animal models of sepsis or human patients, there are substantial physiological changes, many of which may result in subsequent organ injury. Variations in age, gender, and medical comorbidities including diabetes and renal failure create additional complexity that influence the outcomes in septic patients. Specific system-based alterations, such as the coagulopathy observed in sepsis, offer both potential insight and possible therapeutic targets. Intracellular stress induces changes in the endoplasmic reticulum yielding misfolded proteins that contribute to the underlying pathophysiological changes. With these multiple changes it is difficult to precisely classify an individual's response in sepsis as proinflammatory or immunosuppressed. This heterogeneity also may explain why most therapeutic interventions have not improved survival. Given the complexity of sepsis, biomarkers and mathematical models offer potential guidance once they have been carefully validated. This review discusses each of these important factors to provide a framework for understanding the complex and current challenges of managing the septic patient. Clinical trial failures and the therapeutic interventions that have proven successful are also discussed.

Antimicrobial prescribing in hospitalized adults stratified by age: data from the ESAC point-prevalence surveys

BACKGROUND

Geriatric infectious diseases are a major health care issue. Infections in the elderly occur more frequently than in younger adults, are often associated with higher morbidity and mortality, and may present atypically. Elderly patients are also often taking multiple medications, which increases the likelihood of drug-drug interactions. Dosing decisions should take into consideration the reduced lean body mass and declining renal function in this age group.

OBJECTIVE

Antimicrobial prescribing in three age groups (65-74, 75-84 and ≥85 years) was compared with a reference age group (18-64 years), with the aim of identifying quality of care indicators specific to the elderly.

METHODOLOGY

The ESAC (European Surveillance of Antimicrobial Consumption) final phase performed two hospital point-prevalence surveys in 2008 and 2009, respectively, using the defined daily dose (DDD) and Anatomical Therapeutic Chemical (ATC) classification system. The prescribed daily dose (PDD) was compared with the DDD. Differences in prescribing were assessed using multivariate logistic regression analyses.

RESULTS

The majority of patients (19,549 [64% of 30,836]) were from Northern Europe and 13,830 (48%) belonged to the reference group. The largest proportion of patients was admitted through the hospital's medical specialty (55% of patients) [range: 49% in the reference group to 72% in the ≥85 years age group]. Penicillins were the most frequently used antimicrobials in all age groups (range: 32% in the reference group to 41% in the ≥85 years age group). Multivariate analyses showed three significant variations between the 65-74 years age group and the reference group (quinolones: odds ratio [OR] 1.17 [95% CI 1.05, 1.29]; tetracyclines: OR 1.58 [95% CI 1.26, 1.98]; aminoglycosides: OR 0.81 [95% CI 0.70, 0.93]). The number of significant variations increased to seven and eight in the 75-84 and ≥85 years age groups, respectively. A lower likelihood for PDD > DDD was observed in the 65-74 years age group for three parenteral antimicrobials (amoxicillin/clavulanic acid, gentamicin and vancomycin). This was reiterated in the older age groups (75-84 and ≥85 years), where piperacillin/tazobactam, meropenem and oral ciprofloxacin also showed a lower likelihood for PDD > DDD.

CONCLUSIONS

Despite the methodology not being dedicated to elderly patients, the study identified elevated use of antimicrobial agents that are associated with serious adverse effects or a narrow therapeutic index as a target for quality of care improvement in elderly patients.

Outpatient parenteral antibiotic therapy in the elderly: an Italian observational multicenter study

Bacterial infections are the most frequent cause of hospitalization in elderly patients. In the early eighties, the advantages of Outpatient parenteral Antibiotic therapy (OPAT) were identified in the United States, and suitable therapeutic programs were established. In order to understand the different ways of managing OPAT, a National OPAT Registry was set up in 2003 in Italy. This study analyzes data concerning bacterial infections in 176 elderly patients including demographics, therapeutic management, clinical response, and side-effects. Bone and joint infections (48.9%) and skin and soft tissue infections (27.8%) were the most common infections treated with OPAT. Teicoplanin (28.9%) and ceftriaxone (22.1%) were the top two antibiotics chosen. OPAT was mainly performed at a hospital infusion center (52.8%). The clinical success rate was high and side-effects were low (12.6% of cases). Management of bacterial infections in the elderly with an outpatient program is effective and safe.

Pharmacokinetic and Pharmacodynamic Aspects of Antibiotic Use in High-Risk Populations

The study of pharmacokinetics includes the absorption, distribution, metabolism, and elimination of drugs. The pharmacologic effect that a medication has on the body is known as pharmacodynamics. With antimicrobials, pharmacokinetic and pharmacodynamic parameters become especially important because of the association between host drug concentrations, microorganism eradication, and resistance. This article focuses on the pharmacokinetic changes that can occur with antimicrobials when they are used in patients at high risk of infections and how they influence pharmacodynamic effects. The populations described here include patients with obesity and diabetes mellitus, renal or hepatic failure, chronic lung disease, severe burns, and long-term prosthetic devices and the elderly.

Insights into severe sepsis in older patients: from epidemiology to evidence-based management

Up to 60% of patients who develop severe sepsis in the United States are > or =65 years of age, and the incidence of sepsis in this population is steadily increasing. Elderly individuals have an increased risk of developing sepsis, compared with younger patients, because of frequent comorbidities, institutionalization, declining performance status, and altered immune function. The clinical presentation of older patients with sepsis is often atypical, leading to a difficult and delayed diagnosis. Although increasing age appears to confer a high risk of death due to severe sepsis, recent evidence shows that many older patients respond well to selected interventions when the interventions are initiated in a timely fashion. Newly published clinical practice guidelines outline key recommendations regarding the treatment of patients with severe sepsis. Clinicians must be aware of the level of evidence in support of various interventions and must keenly screen older survivors for ongoing deficits that will limit their functional recovery.

New Developments in Antibacterial Choice for Lower Respiratory Tract Infections in Elderly Patients

Elderly patients are at increased risk of developing lower respiratory tract infections compared with younger patients. In this population, pneumonia is a serious illness with high rates of hospitalisation and mortality, especially in patients requiring admission to intensive care units (ICUs). A wide range of pathogens may be involved depending on different settings of acquisition and patient's health status. Streptococcus pneumoniae is the most common bacterial isolate in community-acquired pneumonia, followed by Haemophilus influenzae, Moraxella catarrhalis and atypical pathogens such as Chlamydia pneumoniae, Legionella pneumophila and Mycoplasma pneumoniae. However, elderly patients with comorbid illness, who have been recently hospitalised or are residing in a nursing home, may develop severe pneumonia caused by multidrug resistant staphylococci or pneumococci, and enteric Gram-negative bacilli, including Pseudomonas aeruginosa. Moreover, anaerobes may be involved in aspiration pneumonia. Timely and appropriate empiric treatment is required in order to enhance the likelihood of a good clinical outcome, prevent the spread of antibacterial resistance and reduce the economic impact of pneumonia. International guidelines recommend that elderly outpatients and inpatients (not in ICU) should be treated for the most common bacterial pathogens and the possibility of atypical pathogens. The algorithm for therapy is to use either a selected beta-lactam combined with a macrolide (azithromycin or clarithromycin), or to use monotherapy with a new anti-pneumococcal quinolone, such as levofloxacin, gatifloxacin or moxifloxacin. Oral (amoxicillin, amoxicillin/clavulanic acid, cefuroxime axetil) and intravenous (sulbactam/ampicillin, ceftriaxone, cefotaxime) beta-lactams are agents of choice in outpatients and inpatients, respectively. For patients with severe pneumonia or aspiration pneumonia, the specific algorithm is to use either a macrolide or a quinolone in combination with other agents; the nature and the number of which depends on the presence of risk factors for specific pathogens. Despite these recommendations, clinical resolution of pneumonia in the elderly is often delayed with respect to younger patients, suggesting that optimisation of antibacterial therapy is needed. Recently, some new classes of antibacterials, such as ketolides, oxazolidinones and streptogramins, have been developed for the treatment of multidrug resistant Gram-positive infections. However, the efficacy and safety of these agents in the elderly is yet to be clarified. Treatment guidelines should be modified on the basis of local bacteriology and resistance patterns, while dosage and/or administration route of each antibacterial should be optimised on the basis of new insights on pharmacokinetic/pharmacodynamic parameters and drug interactions. These strategies should be able to reduce the occurrence of risk factors for a poor clinical outcome, hospitalisation and death.

Carbapenems in the treatment of severe community-acquired pneumonia in hospitalized elderly patients: a comparative study against standard therapy

In this open, prospective, study were enrolled 204 hospitalized elderly patients with severe (88 males, 116 females, age range 70-94). Patients were randomized to receive one of the following antibiotic treatment regimens: meropenem 500 mg i.v. t.i.d. (52); imipenem/cilastatin 500 mg i.v. t.i.d. (51), clarithromycin 500 mg + ceftriaxone 1 g i.v. b.i.d. (52), clarithromycin 500 mg + amikacin 250 mg i.v. b.i.d. (49). In 99 cases causative germs were isolated (24 meropenem, 26 imipenem, 23 clarithromycin + ceftriaxone, 26 ceftriaxone + amikacin). A satisfactory clinical, bacteriological response was achieved respectively in 86.5% 77% in meropenem; 86.3% 71% in imipenem/cilastatin; 69% 61% in ceftriaxone + clarithromycin and in 85.7% 77% in clarithromycin + amikacin. The mean total cost for each patient was $1,560; $1,620; $1,760 and $1,792 in meropenem, imipenem/cilastatin, clarithromycin + ceftriaxone and clarithromycin + amikacin respectively. This study shows that treatment with either meropenem or imipenem is as efficacious as conventional therapy in the treatment of community acquired pneumonia (CAP), and that meropenem is the most cost-effective.

Ageing and infection

Average life expectancy throughout developed countries has rapidly increased during the latter half of the 20th century and geriatric infectious diseases have become an increasingly important issue. Infections in the elderly are not only more frequent and more severe, but they also have distinct features with respect to clinical presentation, laboratory results, microbial epidemiology, treatment, and infection control. Reasons for increased susceptibility include epidemiological elements, immunosenescence, and malnutrition, as well as a large number of age-associated physiological and anatomical alterations. Moreover, ageing may be the cause of infection but infection can also be the cause of ageing. Mechanisms may include enhanced inflammation, pathogen-dependent tissue destruction, or accelerated cellular ageing through increased turnover. In most instances, treatment of infection leads to a satisfactory outcome in the elderly. However, in palliative care situations and in patients with terminal dementia, the decision whether or not to treat an infectious disease is becoming a difficult ethical issue.