How Antibiotics Should be Prescribed to Hospitalized Elderly Patients with Community-Acquired Pneumonia

Therapeutic Drug Monitoring of Antibiotics in the Elderly: A Narrative Review

PURPOSE

Antibiotic dosing adaptation in elderly patients is frequently complicated by age-related changes affecting the processes of drug absorption, distribution, metabolism, and/or elimination. These events eventually result in treatment failure and/or development of drug-related toxicity. Therapeutic drug monitoring (TDM) can prevent suboptimal antibiotic exposure in adult patients regardless of age. However, little data are available concerning the specific role of TDM in the elderly.

METHODS

This review is based on a PubMed search of the literature published in the English language. The search involved TDM studies of antibiotics in the elderly performed between 1990 and 2021. Additional studies were identified from the reference lists of the retrieved articles. Studies dealing with population pharmacokinetic modeling were not considered.

RESULTS

Only a few studies, mainly retrospective and with observational design, have specifically dealt with appropriate antibiotic dosing in the elderly based on TDM. Nevertheless, some clinical situations in which the selection of optimal antibiotic dosing in the elderly was successfully guided by TDM were identified.

CONCLUSIONS

Elderly patients are at an increased risk of bacterial infections and inadequate drug dosing compared to younger patients. Therefore, the availability of TDM services can improve the appropriateness of antibiotic prescriptions in this population.

Diagnosis and Management of Heart Failure in Elderly Patients from Hospital Admission to Discharge: Position Paper

Multidisciplinary management of worsening heart failure (HF) in the elderly improves survival. To ensure patients have access to adequate care, the current HF and French health authority guidelines advise establishing a clearly defined HF patient pathway. This pathway involves coordinating multiple disciplines to manage decompensating HF. Yet, recent registry data indicate that insufficient numbers of patients receive specialised cardiology care, which increases the risk of rehospitalisation and mortality. The patient pathway in France involves three key stages: presentation with decompensated HF, stabilisation within a hospital setting and transitional care back out into the community. In each of these three phases, HF diagnosis, severity and precipitating factors need to be promptly identified and managed. This is particularly pertinent in older, frail patients who may present with atypical symptoms or coexisting comorbidities and for whom geriatric evaluation may be needed or specific geriatric syndrome management implemented. In the transition phase, multi-professional post-discharge management must be coordinated with community health care professionals. When the patient is discharged, HF medication must be optimised, and patients educated about self-care and monitoring symptoms. This review provides practical guidance to clinicians managing worsening HF in the elderly.

Pharmacokinetic-pharmacodynamic analysis of ciprofloxacin in elderly Chinese patients with lower respiratory tract infections caused by Gram-negative bacteria

Background:

Ciprofloxacin is usually used in the treatment of lower respiratory tract infections (LRTIs). Recent studies abroad have shown ciprofloxacin is inadequately dosed and might lead to worse outcomes. The aim of this study was to perform pharmacokinetic and pharmacodynamic analyses of ciprofloxacin in elderly Chinese patients with severe LRTIs caused by Gram-negative bacteria.

Methods:

From September 2012 to June 2014, as many as 33 patients were empirically administered beta-lactam and ciprofloxacin combination therapy. Patients were infused with 200 or 400 mg of ciprofloxacin every 12 h, which was determined empirically by the attending physician based on the severity of the LRTI and the patient's renal condition. Ciprofloxacin serum concentrations were determined by high-performance liquid chromatography. Bacterial culture was performed from sputum samples and/or endotracheal aspirates, and the minimum inhibitory concentrations (MICs) of ciprofloxacin were determined. The ratios of the area under the serum concentration-time curve to the MIC (AUC/MIC) and of the maximum serum concentration of the drug to the MIC (C_max/MIC) were calculated. The baseline data and pharmacokinetic parameters were compared between clinical success group and clinical failure group, bacteriologic success group and bacteriologic failure group.

Results:

Among the 33 patients enrolled in the study, 17 were infected with Pseudomonas aeruginosa, 14 were infected with Acinetobacter baumannii, and two were infected with Klebsiella pneumoniae. The mean age of the patients was 76.9 ± 6.7 years. Thirty-one patients (93.4%) did not reach the target AUC/MIC value of >125, and 29 patients (87.9%) did not reach the target C_max/MIC value of >8. The AUC/MIC and C_max/MIC ratios in the clinical success group were significantly higher than those in the clinical failure group (61.1 [31.7–214.9] vs. 10.4 [3.8–66.1], Z = −4.157; 9.6 [4.2–17.8] vs. 1.3 [0.4–4.7], Z = −4.018; both P < 0.001). The AUC/MIC and C_max/MIC ratios in the patients for whom the pathogens were eradicated were significantly higher than those in the patients without the pathogens eradicated (75.3 [31.7–214.9] vs. 10.5 [3.8–66.1], Z = −3.938; 11.4 [4.2–17.8] vs. 1.4 [0.4–5.4], Z = −3.793; P < 0.001 for both). Receiver operating characteristic curve analysis showed that the AUC/MIC and C_max/MIC values were closely associated with clinical and bacteriologic efficacies (P < 0.001 in both).

Conclusions:

Ciprofloxacin is inadequately dosed against Gram-negative bacteria, especially for those with relatively high MIC values. Consequently, the target values, AUC/MIC > 125 and C_max/MIC > 8, cannot be reached.