Effectiveness of Pharmacokinetic/Pharmacodynamic-Guided Meropenem Treatment in Critically Ill Patients: A Comparative Cohort Study.

BACKGROUND: The proper dosage of antibiotics is a key element in the effective treatment of infection, especially in critically ill patients. This study aimed to evaluate the efficacy of optimized meropenem regimens based on pharmacokinetic/pharmacodynamic criteria in patients admitted to the intensive care unit. METHODS: This observational, naturalistic, retrospective, unicentric cohort study was performed between May 2011 and December 2017. The clinical and bacteriologic responses of 77 control intensive care unit patients receiving meropenem were compared with those of 77 propensity score-balanced patients who received meropenem dose adjusted by therapeutic drug monitoring. The primary end point of clinical response was a reduction at the end of treatment of at least 80% of the maximum procalcitonin (PCT) value recorded during the meropenem treatment. RESULTS: The primary end point was met by 55 patients (71.4%) in the adjusted group compared with 41 (53.3%) patients in the control group (mean difference 18.1%, P = 0.02). Fifty-one patients (66.2%) in the adjusted group required a meropenem dose adjustment, being necessary in 46 of them (90.2%) to decrease the dose. The reduction of PCT was the greatest in the adjusted group compared with the unadjusted group (93% versus 85%, P = 0.004); a greater percentage of patients reached a PCT level < 0.5 ng/mL (63.6% versus 41.6%, P = 0.006), and there was a trend toward an improved bacteriologic response (relative risk = 1.27; 95% confidence interval: 0.92-1.56). There were no differences in early mortality or safety between groups. CONCLUSIONS: Adjustment of meropenem therapy by monitoring is a useful strategy for improving meropenem effectiveness in the treatment of infection in critically ill patients, with no impact on safety.

Effectiveness of adjunctive nebulized antibiotics in critically ill patients with respiratory tract infections.

The purpose of the study was to analyze the effectiveness of adding nebulized antibiotics to systemic antimicrobials in critically ill patients with respiratory tract infections (pneumonia or tracheobronchitis) and the effect on renal function. A retrospective observational cohort study including critically ill patients with respiratory tract infections during a 2-year period was conducted. Intervention group included patients that received nebulized and systemic antimicrobials. Patients in the control group received only systemic antimicrobials. Clinical resolution was the primary endpoint. Secondary outcomes included change in fever, inflammatory parameters, and creatinine clearance; length of hospital stay, systemic therapy, and mechanical ventilation; hospital readmission; and mortality. Regression models were performed to estimate the effect of nebulized antibiotics on outcome variables adjusted by potential confounders. A total of 136 patients were included (93 in control group and 43 in intervention group). The intervention group had higher odds of clinical resolution (adjusted odds ratio (OR): 7.1; 95% confidence interval (95% CI): 1.2, 43.3). Nebulized antibiotic therapy was independently associated with reduction in procalcitonin (adjusted OR: 12.4; 95% CI: 1.4, 109.7). There were no significant differences in the rest of the secondary outcomes or in creatinine clearance reduction. Adding nebulized antibiotics for the management of respiratory tract infections has a positive impact on clinical resolution without increasing the risk of renal toxicity.

Impact of the Acceptance of the Recommendations Made by a Meropenem Stewardship Program in a University Hospital: A Pilot Study.

Antimicrobial stewardship programs (ASP) promote appropriate antimicrobial use. We present a 4-year retrospective study that evaluated the clinical impact of the acceptance of the recommendations made by a meropenem-focused ASP. A total of 318 meropenem audits were performed. The ASP team (comprising infectious disease physicians, pharmacists and microbiologists) considered meropenem use in 96 audits (30.2%) to be inappropriate. The reasons to consider these uses inappropriate were the possibility of de-escalating to a narrower-spectrum antibiotic, in 66 (68.7%) audits, and unnecessary meropenem use, in 30 (31.3%) audits. The ASP team recommended de-escalation in 66 audits (68.7%) and discontinuation of meropenem in 30 audits (31.3%). ASP interventions were stratified according to whether or not recommendations were followed. The group in which recommendations were accepted and followed (i.e., accepted audit, AA) included 66 audits (68.7%) and the group in which recommendations were not followed (i.e., rejected audit, RA) included 30 (31.3%) audits. The comorbidity of the AA group (Charlson score) was higher than in the RA group (7.0 (5.0-9.0) vs. 6.0 (4.0-7.0), p = 0.02). Discontinuation of meropenem was recommended in 83.3% of audits in the AA group vs. 62.2% in the RA group (OR 3.05 (1.03-8.99), p = 0.04). Ertapenem de-escalation resulted in a 100% greater rate of follow-up compared with the non-carbapenem option (100% vs. 51.9%, OR 1.50 (1.21-1.860), p = 0.001). Significant differences were observed in the AA group when cultures were taken before antibiotic prescription-98.5% vs. 83.3% (p = 0.01, OR 13.0 (1.45-116.86))-or when screening cultures were taken-45.5% vs. 19.2% (p = 0.03, OR 3.5 (1.06-11.52)). There were no differences between the groups in terms of overall mortality and 30-day mortality, length of stay, Clostridiodes difficile infection, 30-day readmission or hospitalization costs. In conclusion, meropenem ASP recommendations contributed to a decrease in meropenem prescription without worsening clinical and economic outcomes.

Clinical and economic impact of clinical pharmacist interventions regarding antimicrobials on critically ill patients.

BACKGROUND: Incorporating in the Intensive Care Unit (ICU) a clinical pharmacist who performs interventions on antimicrobials may be cost-effective. OBJECTIVES: To evaluate the clinical and economic impact of clinical pharmacist interventions on antimicrobials in an ICU. To identify drug related problems and medication errors detected by the pharmacist. METHODS: A retrospective observational study was performed to analyze drug related problems, medication errors and clinical pharmacist interventions related to antimicrobials in adults admitted to an ICU in a 5-month period. The economic impact of pharmacist interventions was estimated considering difference in cost derived from antimicrobial treatment, adverse drug events and clinical pharmacist time. RESULTS: A total of 212 drug related problems were detected in 114 patients, 18 being medication errors. Clinical pharmacist developed one intervention for each problem identified. 204 interventions (96.2%) were considered important with improved patient care and 7 (3.3%) very important. No negative impact of any intervention was identified. Physicians accepted 97.6% of the interventions. A potential saving of 10,905 € was estimated as a result of pharmacist interventions and 4.8 € were avoided per euro invested in a clinical pharmacist. CONCLUSIONS: A clinical pharmacist performing interventions on antimicrobials in the ICU has a positive impact on patient care and decreases costs.

Efficacy of an adverse drug reaction electronic reporting system integrated into a hospital information system.

BACKGROUND: Adverse drug reaction (ADR) spontaneous reporting is the primary method of postmarketing drug surveillance; although it is an important part of postmarketing drug surveillance, it is underused. Before 2004, almost no ADRs were reported in our 400-bed hospital. As an electronic hospital information system was available in our hospital, we developed a tool (ADR-RS-IHIS) for ADR reporting integrated into the hospital information system to facilitate reporting through easy use, automatic input of certain information, increased accessibility, real-time review, and intervention. OBJECTIVE: To analyze the efficacy of the ADR-RS-IHIS in increasing ADR reporting to the national drug surveillance system, propose and implement improvements to increase ADR reporting, and evaluate the impact of these improvements. METHODS: Every ADR reported through the ADR-RS-IHIS was evaluated retrospectively. Two study phases for evaluating ADR-RS-IHIS efficacy were identified. Phase I took place April 2004-August 2006; in April 2006, an interim analysis was performed to propose improvements. Phase II took place September 2006-April 2007 for evaluation of the impact made by the proposed improvements. Efficacy in the phase I and improvement impact on phase II were measured as the number of ADRs reported to the national drug surveillance system. RESULTS: The rate of ADRs reported per month to the national system increased from 0 before 2004 to 0.91 in phase I and 1.62 in phase II (2.25 if delayed reporting was considered). Improvement measures included: allowing nurses to report ADRs in the same way as physicians and pharmacists, automatic form filling of certain information from the electronic hospital information system, easier ADR report analysis, and automatic notification to the allergy department regarding suspected allergies. CONCLUSIONS: An ADR reporting system integrated into the electronic hospital information system is effective for increasing the number of ADRs reported to the national drug surveillance system. Allowing nurses to report ADRs in a manner similar to that of physicians and pharmacists, as well as automatic entry of certain data into the form, contributes to the improvement of the system.

Morphine-induced hearing loss.

PURPOSE: A case of severe bilateral sensorineural hearing loss associated with oral morphine is reported. SUMMARY: A 52-year-old Spanish man was admitted to the intensive care unit with a Glasgow Coma Scale score of 3, a fever, and sudden hearing loss with tinnitus in both ears. His medical history included type 2 diabetes mellitus, depression, sleep disorder, and hypertension. The patient also had pyelonephritis in 2011 and pulmonary embolism in 2014, requiring the placement of an inferior vena cava filter and chronic anticoagulation. His hearing loss appeared after the initiation of oral morphine, specifically on the eighth day of treatment, with increasing dosages of up to 120 mg daily. We did not find any other possible causes of the hearing loss. Ototoxicity is an adverse reaction of ibuprofen and acetaminophen, but the patient received only three doses of ibuprofen 600 mg and did not require acetaminophen. The patient's other medications did not have ototoxicity as an adverse reaction, and the patient confirmed not to have received any salicylate product. Brain magnetic resonance imaging discarded other possible causes of hearing loss. Our patient's hearing loss did not resolve after opioid discontinuation, and the use of hearing aids was necessary. According to the Naranjo et al. adverse drug reaction probability scale, this event would be classified as "probable." CONCLUSION: A 52-year-old man developed tinnitus and hearing loss after receiving high doses of oral morphine sulfate. His hearing loss did not fully resolve after the discontinuation of morphine, and he required the use of hearing aids.

Linezolid-induced haematological toxicity.

OBJECTIVE: to determine the incidence of linezolid-induced haematological toxicity and study the influence of renal clearance on its appearance and the preventive effect of pyridoxine. METHODS: a retrospective observational study was conducted. Every patient treated with linezolid in a university hospital during 6 months was included. Haematological toxicity was defined as a decrease of 25% in hemoglobin, of 25% in platelets and/or 50% in neutrophils from baseline. The incidence of haematological toxicity and the percentage decrease in analytical variables were compared in patients with and without renal failure (creatinine clearance lower than 50 mL/min), using the 30 mL/min threshold, and with or without pyridoxine; using Chi -Square and U Mann-Whitney tests, respectively. RESULTS: thirty-eight patients were evaluated. Sixteen (42%) presented haematological toxicity (2 due to a decrease in haemoglobin, 9 in platelets and 8 in neutrophils). Two patients (5%) discontinued treatment due to thrombocytopenia. Toxicity incidence was similar in patients with and without renal failure, 42% vs 42%, p = 0.970, with more or less than 30 ml/min, 67% vs 40%, p = 0.369, or with or without pyridoxine, 47.8% vs 33%, p = 0.376. Patients with renal failure had a significantly greater reduction in platelet count, p = 0.0185. CONCLUSION: forty-two percent of patients had haematological toxicity, being more frequent platelets and neutrophils reduction. This was not significantly higher in patients with renal failure or in those without pyridoxine. Greater reduction in platelet count was observed in patients with renal failure.

Objetivo: determinar la incidencia de toxicidad hematológica por linezolid. Estudiar la influencia del aclaramiento renal en su aparición y la efectividad de la piridoxina en su prevención. Método: estudio observacional retrospectivo de todos los pacientes tratados con linezolid en un hospital universitario en seis meses. Se consideró toxicidad hematológica a la disminución del 25% de la hemoglobina, del 25% de las plaquetas y/o del 50% de neutrófilos al final respecto al inicio del tratamiento. Se comparó en los pacientes con y sin fallo renal (aclaramiento de creatinina inferior a 50 mL/min), con más o menos de 30 mL/min, y con o sin piridoxina, la incidencia de toxicidad hematológica mediante Chi-Cuadrado y la disminución en el porcentaje de variables analíticas hematológicas mediante U Mann-Whitney. Resultados: se evaluaron 38 pacientes. Dieciséis (42%) presentaron toxicidad hematológica (2 por disminución de hemoglobina, 9 de plaquetas y 8 de neutrófilos). En 2 pacientes (5%) se suspendió el tratamiento por plaquetopenia. La incidencia de toxicidad fue similar en pacientes con y sin insuficiencia renal, 42% vs. 42%, p = 0,970, con más o menos de 30 mL/min, 67% vs. 40%, p = 0,369, con piridoxina o sin ella, 47,8% vs. 33%, p = 0,376. Los pacientes con fallo renal presentaron una reducción significativamente mayor de plaquetas, p = 0,0185. Conclusiones: un 42% de los pacientes presentó toxicidad hematológica, más frecuentemente disminución de plaquetas y neutrófilos. Esta no fue significativamente mayor en los pacientes con fallo renal, ni en aquellos sin piridoxina. Se halló mayor reducción de plaquetas en los pacientes con insuficiencia renal.

Results of a retrospective observational study of intermediate care staffed by hospitalists: impact on mortality, co-management, and teaching.

BACKGROUND: Hospitalized patients are complex and institutions have to face the high cost of critical care and the limited resources of the ward. Intermediate care appears as an attractive strategy to provide rational care according to patient needs. It is an interesting scenario to expand co-management and teaching. STUDY DESIGN: Retrospective observational study. SETTING: Intermediate care unit (ImCU) of a single academic hospital. PATIENTS AND METHODS: 456 patients admitted from April 2006 to April 2010 were included in the study. Demographics, admission physiologic parameters and in-hospital mortality were recorded. We used the Simplified Acute Physiology Score II (SAPS II) as prognostic score system. Co-management with medical and surgical teams, and the number of training residents were evaluated. RESULTS: In-hospital mortality was 20.6%, whereas the expected mortality was 23.2% based on SAPS II score. The correlation between SAPS II predicted and observed death rates was accurate and statistically significant (Rho = 1.0, p < 0.001). Co-management was performed with several medical and surgical teams, with an increase in perioperative comanagement of 22.7% (p = 0.014). The number of training residents in ImCU increased from 4.3% to 30.4% (p = 0.002) CONCLUSIONS: An ImCU led by hospitalists showed encouraging results regarding patient survival and SAPS II is an useful tool for prognostic evaluation in this population. Intermediate care serves as an expansion of role for hospitalists; and clinicians, trainees and patients may benefit from co-management and teaching opportunities at this unique level of care.

Linezolid-induced haematological toxicity / Toxicidad hematológica inducida por linezolid

Objective: to determine the incidence of linezolid-induced haematological toxicity and study the influence of renal clearance on its appearance and the preventive effect of pyridoxine. Methods: a retrospective observational study was conducted. Every patient treated with linezolid in a university hospital during 6 months was included. Haematological toxicity was defined as a decrease of 25% in hemoglobin, of 25% in platelets and/or 50% in neutrophils from baseline. The incidence of haematological toxicity and the percentage decrease in analytical variables were compared in patients with and without renal failure (creatinine clearance lower than 50 mL/min), using the 30 mL/min threshold, and with or without pyridoxine; using Chi -Square and U Mann-Whitney tests, respectively. Results: thirty-eight patients were evaluated. Sixteen (42%) presented haematological toxicity (2 due to a decrease in haemoglobin, 9 in platelets and 8 in neutrophils). Two patients (5%) discontinued treatment due to thrombocytopenia. Toxicity incidence was similar in patients with and without renal failure, 42% vs 42%, p = 0.970, with more or less than 30 ml/min, 67% vs 40%, p = 0.369, or with or without pyridoxine, 47.8% vs 33%, p = 0.376. Patients with renal failure had a significantly greater reduction in platelet count, p = 0.0185. Conclusion: forty-two percent of patients had haematological toxicity, being more frequent platelets and neutrophils reduction. This was not significantly higher in patients with renal failure or in those without pyridoxine. Greater reduction in platelet count was observed in patients with renal failure (AU)

Objetivo: determinar la incidencia de toxicidad hematológica por linezolid. Estudiar la influencia del aclaramiento renal en su aparición y la efectividad de la piridoxina en su prevención. Método: estudio observacional retrospectivo de todos los pacientes tratados con linezolid en un hospital universitario en seis meses. Se consideró toxicidad hematológica a la disminución del 25% de la hemoglobina, del 25% de las plaquetas y/o del 50% de neutrófilos al final respecto al inicio del tratamiento. Se comparó en los pacientes con y sin fallo renal (aclaramiento de creatinina inferior a 50 mL/min), con más o menos de 30 mL/min, y con o sin piridoxina, la incidencia de toxicidad hematológica mediante Chi-Cuadrado y la disminución en el porcentaje de variables analíticas hematológicas mediante U Mann-Whitney. Resultados: se evaluaron 38 pacientes. Dieciséis (42%) presentaron toxicidad hematológica (2 por disminución de hemoglobina, 9 de plaquetas y 8 de neutrófilos). En 2 pacientes (5%) se suspendió el tratamiento por plaquetopenia. La incidencia de toxicidad fue similar en pacientes con y sin insuficiencia renal, 42% vs. 42%, p = 0,970, con más o menos de 30 mL/min, 67% vs. 40%, p = 0,369, con piridoxina o sin ella, 47,8% vs. 33%, p = 0,376. Los pacientes con fallo renal presentaron una reducción significativamente mayor de plaquetas, p = 0,0185. Conclusiones: un 42% de los pacientes presentó toxicidad hematológica, más frecuentemente disminución de plaquetas y neutrófilos. Esta no fue significativamente mayor en los pacientes con fallo renal, ni en aquellos sin piridoxina. Se halló mayor reducción de plaquetas en los pacientes con insuficiencia renal (AU)

Pharmacodynamics of high-dose methotrexate in pediatric patients.

OBJECTIVE: To establish a relationship between the pharmacokinetics of high-dose methotrexate (MTX) and toxicity in children of a pediatric oncology department and to reassess MTX concentrations at which the patients would be at high risk for toxic effects. METHODS: This study included 37 patients (227 treatment courses) who received a median dose of 4.87 g/m(2) of MTX in a 4-hour infusion. The population pharmacokinetic parameters of MTX were estimated by parametric (IT2B) and nonparametric methods (NPEM). Gastrointestinal, renal, and hematologic toxicity were evaluated. The relationship between pharmacokinetic parameters and toxicity was analyzed by logistic regression and multiple linear regression. RESULTS: Equations to predict hematologic and nonhematologic toxicity were obtained. An increase of 100 micro mol/L in the MTX peak concentration meant a 12% (p = 0.03) higher risk of vomiting; a significant delay in MTX elimination implied a 5.76-fold higher risk of mucositis (p < 0.001). An increase of 1 micro mol/L in the MTX concentration 24 hours after the end of the infusion (Cp(24h)) led to a 43% increase in the risk of renal toxicity (p < 0.001). Hematologic toxicity was significantly conditioned by the baseline leukocyte count and Cp(24h) (p < 0.001). CONCLUSIONS: The analysis of high-dose MTX pharmacokinetic/pharmacodynamic relationship to toxicity has led to equations able to predict toxicity that are easily applicable to daily practice. Cp(24h) >3.5 micro mol/L was confirmed as an indicator of high risk of toxicity.

Methotrexate pharmacokinetics and survival in osteosarcoma.

BACKGROUND: The aim of this study was to analyze the relationship between exposure to high-dose methotrexate (HDMTX) and tumor response in terms of survival in children with osteosarcoma. PROCEDURE: This study included 44 patients (479 courses) who received a median dose of 5.92 g/m2 of MTX (interquartile range (IQR) 2.37 g/m2) in a 4-hr infusion. The mean area under the concentration-time curve (AUC) estimated by parametric methods (non-parametric expectation maximization, NPEM), and the mean concentration at the end of the infusion were considered to be the exposure parameters. Tumor response was recorded as disease-free survival (DFS), overall survival (OS), and histologic tumor response. The relationship between MTX exposure and survival parameters was analyzed by Cox regression. RESULTS: The group of 11 patients who were the least exposed to MTX (AUC <2,400 micromol/L hr) presented a high DFS, probably due to the shorter interval of time between MTX courses that led to a higher dose density. In patients with AUC >2,400 micromol/L hr, an increase in the AUC was related to an increase in the DFS. Significant differences were observed in the DFS between patients whose mean AUC was below or above 4,000 micromol/L hr (P=0.024), such that 4,000 micromol/L hr was considered as the minimum AUC to be aimed at for future patients. CONCLUSIONS: Dose density seems to be an important factor in osteosarcoma response, but this must be confirmed in further studies. In order to improve the response to osteosarcoma in children, it is recommended that the dose of MTX to be increased such as to obtain an AUC higher than 4,000 micromol/L hr.