Dose optimization of piperacillin/tazobactam in critically ill children.

Objectives: To characterize the population pharmacokinetics of piperacillin and tazobactam in critically ill infants and children, in order to develop an evidence-based dosing regimen. Patients and methods: This pharmacokinetic study enrolled patients admitted to the paediatric ICU for whom intravenous piperacillin/tazobactam (8:1 ratio) was indicated (75 mg/kg every 6 h based on piperacillin). Piperacillin/tazobactam concentrations were measured by an LC-MS/MS method. Pharmacokinetic data were analysed using non-linear mixed effects modelling. Results: Piperacillin and tazobactam blood samples were collected from 47 patients (median age 2.83 years; range 2 months to 15 years). Piperacillin and tazobactam disposition was best described by a two-compartment model that included allometric scaling and a maturation function to account for the effect of growth and age. Mean clearance estimates for piperacillin and tazobactam were 4.00 and 3.01 L/h for a child of 14 kg. Monte Carlo simulations showed that an intermittent infusion of 75 mg/kg (based on piperacillin) every 4 h over 2 h, 100 mg/kg every 4 h given over 1 h or a loading dose of 75 mg/kg followed by a continuous infusion of 300 mg/kg/24 h were the minimal requirements to achieve the therapeutic targets for piperacillin (60% f T >MIC >16 mg/L). Conclusions: Standard intermittent dosing regimens do not ensure optimal piperacillin/tazobactam exposure in critically ill patients, thereby risking treatment failure. The use of a loading dose followed by a continuous infusion is recommended for treatment of severe infections in children >2 months of age.

Augmented renal clearance implies a need for increased amoxicillin-clavulanic acid dosing in critically ill children.

There is little data available to guide amoxicillin-clavulanic acid dosing in critically ill children. The primary objective of this study was to investigate the pharmacokinetics of both compounds in this pediatric subpopulation. Patients admitted to the pediatric intensive care unit (ICU) in whom intravenous amoxicillin-clavulanic acid was indicated (25 to 35 mg/kg of body weight every 6 h) were enrolled. Population pharmacokinetic analysis was conducted, and the clinical outcome was documented. A total of 325 and 151 blood samples were collected from 50 patients (median age, 2.58 years; age range, 1 month to 15 years) treated with amoxicillin and clavulanic acid, respectively. A three-compartment model for amoxicillin and a two-compartment model for clavulanic acid best described the data, in which allometric weight scaling and maturation functions were added a priori to scale for size and age. In addition, plasma cystatin C and concomitant treatment with vasopressors were identified to have a significant influence on amoxicillin clearance. The typical population values of clearance for amoxicillin and clavulanic acid were 17.97 liters/h/70 kg and 12.20 liters/h/70 kg, respectively. In 32% of the treated patients, amoxicillin-clavulanic acid therapy was stopped prematurely due to clinical failure, and the patient was switched to broader-spectrum antibiotic treatment. Monte Carlo simulations demonstrated that four-hourly dosing of 25 mg/kg was required to achieve the therapeutic target for both amoxicillin and clavulanic acid. For patients with augmented renal function, a 1-h infusion was preferable to bolus dosing. Current published dosing regimens result in subtherapeutic concentrations in the early period of sepsis due to augmented renal clearance, which risks clinical failure in critically ill children, and therefore need to be updated. (This study has been registered at Clinicaltrials.gov as an observational study [NCT02456974].).

Expected net benefit of clinical pharmacy in intensive care medicine: a randomized interventional comparative trial with matched before-and-after groups.

RATIONALE, AIMS AND OBJECTIVES: This study evaluated clinical pharmacy costs against drug costs. METHOD: We conducted a randomized interventional comparative trial at the surgical intensive care unit (ICU) of Ghent University Hospital, Belgium (period B: group B1 with pharmacist consultation; control group B0). We obtained before (period A) and after (period C) control groups using 1:1 propensity score matching with B1 and B0. Mean daily ICU drug costs with standard error of the mean (SEM) were compared between B1 and B0 (primary analysis) and between matched pairs (AB1, AB0, CB1 and CB0; secondary analysis). For B, we performed a 1000 bootstrapping (by resampling B1 and B0), calculated the benefit-cost ratio using pharmacy time (gross salary) as cost (euros) and drug cost savings as benefit. We performed sensitivity analysis with and without outlier drug costs (i.e. twice the standard deviation). PERSPECTIVE: Belgian health care payer. RESULTS: In period B, 135 patients were randomized: B0, n = 60; B1, n = 75. Pharmacists provided recommendations in 148/706 (21.0%) therapies with 83.1% acceptance. Mean drug cost difference between B0 (430.6 euros, SEM 406.0) and B1 (221.2 euros, SEM 58.7) (P = 0.870) became significant after excluding outlier drug costs (B0, 184.4 euros, SEM 42.5; B1, 90.5 euros, SEM 17.7; P < 0.001). Recommendations were cost-beneficial (break-even drug costs or savings) in 53.8% of patients with a benefit-cost ratio of 25:1 (confidence interval -5:1 to 94:1). In sensitivity analysis excluding outlier drug costs, B0 costs were significantly higher than both A and C, indicating high baseline expenses in B0. CONCLUSIONS: The randomized interventional comparative trial in a small ICU patient group suggested the potential cost-benefit of clinical pharmacy on daily ICU drug costs. However, after matching, this benefit was attenuated. A final conclusion demands a larger randomized trial adopting a similar design with matched controls. Future research should include clinical impact of recommendations.

Prophylactic use of levofloxacin during medicinal leech therapy.

BACKGROUND: Medicinal leech therapy is effective in establishing venous outflow in congested flaps and replants. However, its use is also associated with infections, especially from Aeromonas species. To prevent this nosocomial infection, levofloxacin has been established as prophylaxis during leech therapy in our hospital. OBJECTIVES: To study the implementation rate of a guideline, to study the effect of levofloxacin on possible Aeromonas infections, and to evaluate the financial impact of this preventive measure. SETTING: A retrospective analysis on all patients treated with Hirudo medicinalis between July 2007 and March 2011 was performed at the Ghent University Hospital, Belgium. METHOD: A list of patients treated with leeches was retrieved from the pharmacy database. Patient characteristics, date of start and stop of leech therapy were collected. Data on routine diagnostic cultures during leech therapy, date and type of clinical sample, while cultivated micro-organism with antibiotic susceptibility were obtained from the laboratory database. MAIN OUTCOME MEASURE: percentage implementation rate of a guideline, presence of Aeromonas infections, financial impact of levofloxacin prophylaxis. RESULTS: Fifty-one patients were treated with leeches. Forty-six (90.2 %) patients were treated according the guideline. Fourteen out of 51 patients (27.5 %) were suspected for postoperative wound infections. From them, 60 clinical samples were sent for microbiological analysis. These included exudates (26.7 %), peroperative samples (5.0 %), puncture fluid (1.7 %), blood cultures (3.3 %) or smears from burns (63.3 %). No Aeromonas species were cultivated. Comparison between period before and after implementation of levofloxacin prophylaxis revealed that levofloxacin prevents colonization or infection with Aeromonas species in relation to leech therapy. The direct cost for levofloxacin prophylaxis in the current study was 2,570 euro. Based on data obtained in a previous study, we presume that a minimum cost-saving of 20,500 euro was realised during the current study period by implementation of antimicrobial prophylaxis. CONCLUSIONS: This study demonstrates successful implementation of a guideline for levofloxacin prophylaxis during leech therapy. Following its introduction, no Aeromonas species related to the use of leeches were isolated as compared to 8.5 % in the baseline period.

Epidemiology and cost analysis of pharmacist interventions at Ghent University Hospital.

BACKGROUND: Performing bedside clinical recommendations is important for the prevention of adverse drug events. From an economic perspective, the economic value of adverse drug event avoidance needs to be weighed against the labour costs of pharmacists. OBJECTIVE: To perform a cost analysis of pharmacist interventions with valproic acid, digoxin, methotrexate and penicillin. SETTING: Ghent University Hospital in Belgium (1,062-beds). METHOD: Interventions for valproic acid, digoxin, methotrexate and penicillin were selected from a clinical pharmacy database, CLINOR. The average number of registered interventions per year was 1,209 (period 2005-mid 2011). MAIN OUTCOME MEASURE: Cost difference (cost value) between that of the avoided toxicity and that of the intervention (a positive cost value is cost saving). RESULTS: Per annum, pharmacists performed interventions for valproic acid (n = 18) and digoxin (n = 21); the annual cost value of interventions for valproic acid was €18,853.7 with a standard deviation of €15,020.6; for digoxin it was €41,832.0 ± €15,348.5. With oral methotrexate, accidental toxicity occurs rarely but it can be life threatening. Two important pharmacist interventions were reported per year. The routine switching of penicillin therapy to alternative antibiotics, in patients with previous allergy, may invoke costs rather than benefits (two interventions per year). In half of cases, therapy was reinitiated without any further adverse drug event. CONCLUSION: Clinically important pharmacy interventions are not automatically cost beneficial. Interventions that prevent digoxin and valproic acid toxicity were cost effective in this setting. The routine advice to switch the antibiotic class for every reported penicillin allergy is unlikely to avoid adverse drug events and challenges the cost value of this intervention. Interventions with methotrexate are relevant because they can be lifesaving. However, due to their low incidence, effective detection of these errors is crucial for reducing harm.

The use of hypnosedative drugs in a university hospital: has anything changed in 10 years?

AIM: Our goal was to investigate the use of hypnosedatives (HSs) before and during hospitalization, explore the relationship between their use and various demographic and clinical variables, and compare the results with data from a similar 2000 study with particular interest in adherence to hospital formulary guidelines. METHODS: A cross-sectional observational survey of 326 hospitalized patients recruited from ten wards of the Ghent University Hospital, Gent, Belgium, with a patient interview and by evaluating medical and nursing files. RESULTS: In 30.7% of patients, the use of a HS before admission was reported. According to the patient interview, 33.1% used a HS during hospitalization. However, according to medical and nursing files, use of HSs in the hospital was 10% higher (43.3%). In 19.4% of patients who took HSs before admission, their use was discontinued in the hospital. In 15.6% of patients who took no HS before admission, a HS was started in the hospital, according to the formulary guidelines (data from files). There was a positive correlation between HS use in the hospital and older age, longer hospitalization, not coming from home, higher number of HSs taken before hospitalization, sleeping problems emerging during hospitalization, and central nervous system (CNS) disorders. In comparison with 2000, we registered a slight decrease in HS use during hospitalization and a decrease in the number of newly started patients. CONCLUSIONS: The prevalence of HS use in our university hospital is high, mostly as a result of continuation of HSs started before admission, as there seems to be no general policy of active cessation. Compared with the survey performed 10 years ago, fewer hospitalized patients are newly started on HSs, and when this is the case, the formulary guidelines are followed.

Implementation of guidelines for sequential therapy with fluoroquinolones in a Belgian hospital.

OBJECTIVE: This study measured the impact of three interventions for physicians, in order to implement guidelines for sequential therapy (intravenous to oral conversion) with fluoroquinolones. SETTING: A Belgian university hospital with 1,065 beds. Method The first intervention consisted of the hospital-wide publication of guidelines in the local drug letter towards all prescribers. The consumption of fluoroquinolones was measured by means of an interrupted time-series (ITS) analysis 21 months before (period A) and 24 months after publication (period B). The second intervention was an educational interactive session, by infectious disease specialists, to the medical staff of orthopaedics and endocrinology. The third intervention comprised a proactive conversion programme on the abdominal surgery, gastro-enterology and plastic surgery wards, where pharmacists attached a pre-printed note with a suggestion to switch to an oral treatment every time a patient met the criteria for switching. The second and third intervention took place 6 months after the first intervention. Fluoroquinolone treatments were evaluated during a 2 month period before (group 1) and after the introduction of the second (group 2) and third (group 3) intervention. MAIN OUTCOME MEASURE: The monthly ratio of intravenous versus total fluoroquinolone consumption (daily defined doses per 1,000 bed days) was measured to assess the impact of the first intervention. The impact of the second and third intervention was measured in relation to the number of days that intravenous therapy continued beyond the day that the patient fulfilled the criteria for sequential therapy and the antibiotic cost. RESULTS: The ITS demonstrated a reduction of 3.3% in the ratio of intravenous versus total consumption after the publication of the guidelines (P = 0.011). In group 1, patients were treated intravenously for 4.1 days longer than necessary. This parameter decreased in group 2 to 3.5 days and in group 3 to 1.0 day (P = 0.006). The mean additional cost for longer intravenous treatment decreased from 188.0 euro in group 1, to 103.0 euro in group 2 and 44.0 euro in group 3 (P = 0.037). CONCLUSION: This study demonstrated that active implementation of guidelines is necessary. A proactive conversion programme by a pharmacist resulted in a reduction in the duration of the intravenous treatment, and the treatment cost.

Recommended structure for reporting economic evaluation on pharmaceuticals in Belgium.

Pharmaco-economic evaluations become more important for the reimbursement of pharmaceuticals, and will be obligatory for new pharmaceutical drugs for which an added therapeutic value is claimed and a price premium is proposed by the manufacturer. Therefore, it is important to guide purchasers and providers of pharmaceutical care in their efforts related to the evaluation process. Standard Report Format can support the quality, transparency and exhaustiveness of the data submitted. A multidisciplinary task force developed a Standard Report Format for pharmaco-economic evaluations in Belgium.