Antibiotic dosing adjustments in patients with declined kidney function at a tertiary hospital in Jordan

Impact of therapeutic drug monitoring of antibiotics in the management of infective endocarditis

Treatment of infective endocarditis (IE) is based on high doses of antibiotics with a prolonged duration. Therapeutic drug monitoring (TDM) allows antibiotic prescription optimization and leads to a personalized medicine, but no study evaluates its interest in the management of IE. We conducted a retrospective, bicentric, descriptive study, from January 2007 to December 2019. We included patients cared for IE, defined according to Duke's criteria, for whom a TDM was requested. Clinical and microbiological data were collected after patients' charts review. We considered a trough or steady-state concentration target of 20 to 50 mg/L. We included 322 IE episodes, corresponding to 306 patients, with 78.6% (253/326) were considered definite according to Duke's criteria. Native valves were involved in 60.5% (185/306) with aortic valve in 46.6% (150/322) and mitral in 36.3% (117/322). Echocardiography was positive in 76.7% (247/322) of cases. After TDM, a dosage modification was performed in 51.5% (166/322) (decrease in 84.3% (140/166)). After initial dosage, 46.3% (82/177) and 92.8% (52/56) were considered overdosed, when amoxicillin and cloxacillin were used, respectively. The length of hospital stay was higher for patient overdosed (25 days versus 20 days (p = 0.04)), and altered creatinine clearance was associated with overdosage (p = 0.01). Our study suggests that the use of current guidelines probably leads to unnecessarily high concentrations in most patients. TDM benefits predominate in patients with altered renal function, but probably limit adverse effects related to overdosing in most patients.

Antibiotic dosing adjustments in hospitalized patients with chronic kidney disease: a retrospective chart review

BACKGROUND

Infections in patients with chronic kidney disease (CKD) are a major cause of hospitalization. The pharmacokinetics of renally eliminated antibiotics may lead to drug accumulation, resulting in potential toxicity. The renal dosing adjustment of antibiotics is crucial to avoid toxicity and decrease mortality. In Lebanon, limited data are available on antibiotic dose adequacy in CKD.

OBJECTIVES

To estimate the prevalence of inappropriately dosed antibiotics in non-dialysis CKD patients and to identify possible risk factors that may be associated with unadjusted renal dosing.

METHODS

A retrospective chart review was conducted at two tertiary-care hospitals in Lebanon. International Statistical Classification of Diseases (ICD-10) code for CKD was used to search the databases. Demographic and clinical data were collected for patients who received antibiotics that requires renal dosing adjustment. Lexi-Comp online Drug Information database was the guideline used to evaluate the appropriateness of dosing.

RESULTS

A total of 495 antibiotic orders were dispensed to 190 patients. 51.6% of patients received antibiotics without renal dose adjustments. The most inappropriately dosed class was penicillins (39.8%), while fluoroquinolones were the most adequately adjusted. Piperacillin/tazobactam was the most frequently prescribed drug (30.6%) without renal dose adjustment. Respiratory infections (OR 1.301, CI 95% 1.327-1.915) and multimorbidity (OR 1.183, CI 95% 1.358-2.081) were statistically highly significant associations for unadjusted antibiotic dosing from the fitted multivariable-adjusted logistic models.

CONCLUSION

Our study revealed a high frequency of guideline-discordant antibiotic dosing in patients with CKD. This dosing error is preventable by increasing awareness of prescribing physicians and collaborating with clinical pharmacists.