Vancomycin Serum Concentration Monitoring Research Articles

Vancomycin removal and pharmacokinetics during accelerated venovenous hemofiltration.

Vancomycin pharmacokinetics are affected by renal replacement therapy and physiologic changes in critically ill patients. Literature regarding vancomycin removal and pharmacokinetics during accelerated venovenous hemofiltration (AVVH), a form of prolonged intermittent renal replacement therapy, is limited. To describe the removal and pharmacokinetics of vancomycin during AVVH. Eighteen critically ill adults receiving vancomycin and AVVH were included. Vancomycin serum concentrations were obtained within 4 h before and 2-6 h after the AVVH session. Patients' serum concentrations were plotted against time, and individual pharmacokinetic parameters were determined by a one-compartmental analysis. Continuous data are reported as a median (interquartile range [IQR]) and categorical data as a percentage. The median AVVH effluent rate was 39.3 mL/kg/h (IQR 35.5-48 mL/kg/h) for a duration of 9 h (IQR 8-9.75 h). AVVH decreased vancomycin concentrations by 29.8% (IQR 24.9%-35.9%), at a rate of 3.4% per hour (IQR 3.1%-4.3% per hour) of AVVH. The vancomycin elimination rate constant and half-life were 0.039 h-1 (IQR 0.036-0.053 h-1 ) and 17.6 h (IQR 13.1-18.8 h), respectively. The area under the curve during AVVH was 171.7 mg*h/L (IQR 149.1-190 mg*h/L). The volume of distribution in 10 patients was 1 L/kg (IQR 0.73-1.1 L/kg). After AVVH, vancomycin 1000 mg (IQR 750-1000 mg) was needed to maintain a serum trough concentration ≥15 mg/L. Vancomycin is significantly removed by AVVH, which requires supplemental dosing after completion of the AVVH session to maintain desired serum concentrations. Therapeutic drug monitoring of vancomycin serum concentrations is recommended for patients undergoing AVVH.

The intravenous vancomycin prescription practices of French infectious disease specialists: A cross-sectional observational study

IntroductionVancomycin prescription modalities remain non-consensual. We examined and evaluated the vancomycin prescription habits of infectious disease specialists in France. MethodsThrough an anonymized online questionnaire sent to members of the French Infectious Diseases Society, detailed information on vancomycin prescription modalities was collected. ResultsOut of the 712 physicians contacted, 179 (25%) completed the questionnaire; 174 (97%) of them routinely prescribed intravenous vancomycin: 95 (55%) by continuous infusion only, 12 (7%) by intermittent infusion, while 67 (38%) used the two modalities.Among continuous administration users, 157 (97%) applied a loading dose of 15 mg/kg or less (n = 80, 49%), 20–25 mg/kg (n = 33, 20%), or 30 mg/kg or more (n = 45, 28%); 143 (88%) used a maintenance dosage of 30 mg/kg/day and 157 (97%) carried out drug monitoring. ConclusionIn France, infectious disease specialists favor continuous administration of vancomycin using a loading dose, with systematic monitoring of vancomycin serum concentrations.

Precision and accuracy of commercial assays for vancomycin therapeutic drug monitoring: evaluation based on external quality assessment scheme.

Vancomycin remains a mainstay of the treatment of Gram-positive bacterial infections. It is crucial to accurately determine vancomycin serum concentration for adequate dose adjustment. To evaluate the precision and accuracy of commercial assay techniques for vancomycin concentration and to assess the comparability of vancomycin detection methods in Chinese laboratories. Human serum samples spiked with known concentrations of vancomycin were provided to laboratories participating in the external quality assessment scheme (EQAS). Assay methods included chemiluminescence, enzyme immunoassay (EIA) and so on. The dispersion of the measurements was analysed and the robust coefficient of variation (rCV), relative percentage difference (RPD) and satisfactory rate for method groups were calculated. Moreover, performance of the Chinese laboratories was assessed. A total of 657 results from 75 laboratories were collected, including 84 samples from 10 Chinese laboratories. The median rCV, median RPD and satisfactory rates classified by methods ranged from 1.85% to 15.87%, -14.75% to 13.34% and 94.59% to 100.00%, respectively. Significant differences were seen in precision, between kinetic interaction of microparticles in solution (KIMS) and other methods, and in accuracy, between enzyme-multiplied immunoassay technique (EMIT), fluorescence polarization immunoassay (FPIA) and other techniques. Vancomycin detection in China mainly depended on the chemiluminescence and EMIT methods, which tended to result in lower measurements. Although almost all assays in this study achieved an acceptable performance for vancomycin serum concentration monitoring, obvious inconsistencies between methods were still observed. Chinese laboratories were more likely to underestimate vancomycin concentrations. Thus, recognizing inconsistencies between methods and regular participation in vancomycin EQAS are essential.

Single-dose and Steady-state Pharmacokinetics of Vancomycin in Critically Ill Patients Admitted to Medical Intensive Care Unit of India.

ABSTRACTRationaleVancomycin remains the standard of care for gram-positive bacterial infections, though there are significant developments in newer antibacterial agents. Efficacy can be improved by linking pharmacokinetic with pharmacodynamic principles, thus leading to optimum antibiotic exposure. There is scarcity of pharmacokinetic data in Indian intensive care unit (ICU) population.Materials and methodsFifteen subjects with suspected or proven gram-positive bacterial infection of either gender between 18 years and 65 years of age were enrolled. Vancomycin at the dose of 1 g every 12 hours was administered over 1-hour period and pharmacokinetic assessments performed on blood samples collected on days 1 and 3. Vancomycin concentrations were measured on validated liquid chromatography mass spectrometry method. Pharmacokinetic parameters were calculated using Winnonlin (Version 6.3; Pharsight, St. Louis, MO).ResultsThe mean Cmax, elimination half-life, AUC0–12hours, volume of distribution, and clearance of single dose were 36.46 μg/mL (±14.87), 3.98 hours (±1.31), 113.51 μg/mL (±49.51), 52.01 L (±31.31), and 8.90 mL/minute (±3.29), respectively, and at steady state were 40.87 μg/mL (±19.29), 6.27 hours (±3.39), 147.94 μg/mL (±72.89), 56.39 L (±42.13), and 6.98 mL/minute (±4.48), respectively. The elimination half-life increased almost two-fold at steady state. The steady state mean AUC0–24 was 295.89 µg/mL (±153.82). Out of 45 trough levels, 32 (71.11%) concentrations were below recommended range.ConclusionRecommended AUC0–24hours and trough concentrations were not achieved in majority of patients with current dosing, suggesting reevaluation of current vancomycin dosing. Individualized treatment based on close monitoring of vancomycin serum concentrations in critically ill patients is imperative.How to cite this articleMali NB, Deshpande SP, Wandalkar PP, Gupta VA, Karnik ND, Gogtay NJ, et al. Single-dose and Steady-state Pharmacokinetics of Vancomycin in Critically Ill Patients Admitted to Medical Intensive Care Unit of India. IJCCM 2019;23(11):513–517.

Monitoring of vancomycin serum concentrations and the evaluation of its safety and treatment outcomes in adult patients

To investigate the relationship between the serum level of vancomycin and its clinical efficacy as well as adverse reactions in adult patient so as to provide recommendations for clinical management. An open observational research was performed from 1st July 2013 to 31st December 2017 in Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, which recruited the adult patients who were infected with Gram positive (G+) bacteria and treated with vancomycin. The initial dose was decided by the patient's creatinine clearance rate, and the treating dose was directed by the serum drug concentration and the patient's clinical response. By recording the associated clinical information (pathogen eradication, blood test results, adverse reactions, etc.), the clinical outcome and adverse reactions for vancomycin to treat G+ bacterial infections were analyzed. Eighty-nine cases who meet research standards were finally recruited, with 67.42% of male patients, and an average age of (50.5±17.9) years. The most common type of infection was bloodstream infection (61.80%), followed by low respiratory infection (17.98%). Infections caused by Staphylococcus aureus accounted for 39.33%. The bacterial eradication rate was 89.89% (80/89) and the total effective rate was 77.53% (69/89). The effective rate was 80.30% (53/66) with minimum inhibitory concentration (MIC) < 2 mg/L vs. 69.57% (16/23) with MIC ≥ 2 mg/L, the difference was not statistically significant (χ2 = 1.129, P = 0.288). The effective rate was 72.92% (35/48) with trough levels < 10 mg/L vs. 82.93% (34/41) with trough levels ≥ 10 mg/L, the difference was not statistically significant (χ2 = 1.272, P = 0.259). There were 4 cases of vancomycin associated nephrotoxicity, the incidence of nephrotoxicity was 4.49%, and the vancomycin serum trough levels were 17.22-28.53 mg/L. There were 33 cases of liver dysfunction, and elevated γ-glutamine transferase, alkaline phosphatase and aspartate aminotransferase were most common. There were 2 cases of neutropenia and 2 patients appeared rash during vancomycin period. Treatment outcomes were similar regardless of vancomycin MIC and serum trough level. The incidence of vancomycin associated nephrotoxicity rises apparently when serum trough level is over 15 mg/L. Chinese Clinical Trail Registry, ChiCTR-OPC-16007920.

Optimizing initial vancomycin dosing in burn patients

Rationale Burned patients have altered vancomycin pharmacokinetics necessitating adjusted dosing. Published initial dosing recommendations to target troughs of 15–20 mg/L for this population are lacking. Objective This study was conducted to develop initial vancomycin dosing recommendations based on the pharmacokinetics of vancomycin in acute burn patients. Methods A retrospective chart review of 49 vancomycin treated burn patients was conducted. Mean pharmacokinetic parameters were determined and Monte Carlo Simulation was used to develop initial vancomycin dosing recommendations that target trough concentrations between 15 and 20 mg/L. Results Vancomycin pharmacokinetic parameters were significantly ( p < 0.05) different for vancomycin levels obtained 48 h to 14 days after burn versus >14 days after burn. Monte Carlo simulation indicated that the most commonly used empiric dosing regimen (1 g iv q12 h) attained targets with a probability of <10% in all burned patients. The probability of attaining targets was optimized to 20–25% by using 1.5 g iv q8 h, 1.75 g iv q8 h, 1 g iv q6 h, 1.25 g iv q6 h or 750 mg iv q4 h in patients 48 h to 14 days after burn and 1–1.25 g iv q8 h or 500 mg iv q4 h in patients >14 days after burn. Conclusions This study provides initial vancomycin dosing recommendations for burned patients 48 h to 14 days after burn and patients >14 days after burn. However, because of the heterogeneity in pharmacokinetics and the observation that vancomycin pharmacokinetics change with time after burn, monitoring of vancomycin serum concentrations is required to ensure targets are met and maintained.

Predictability of vancomycin trough concentrations using seven approaches for estimating pharmacokinetic parameters

Seven methods for estimating vancomycin pharmacokinetic parameters were studied to determine which method best predicted measured concentrations for patients at a community teaching hospital. Data from adult patients who were given vancomycin and had at least one steady-state trough concentration measured were retrospectively reviewed. Data analyzed included laboratory test values, concomitant medications, weight, height, sex, age, laboratory cultures, medical procedures performed, vancomycin dose and interval, measured vancomycin concentrations, and time of measurement. Relevant data were used in seven predictor methods that estimate volume of distribution, vancomycin clearance, and elimination rate constant to determine which yielded the best predictions of actual measured concentrations in the patient population. Data from 189 patients were included in the analyses. The coefficients of determination for the methods ranged from 0.114 to 0.234. Bias ranged from -5.90 to 0.69 mg/L, and precision ranged from 6.05 to 8.08. The Matzke method had the best combination of the least bias and best precision. Predictions were within 2.5 and 5 mg/L of measured concentrations 18.0-43.9% and 43.4-66.1% of the time, respectively. The percentage of predictions within 25% and 50% of measured concentrations ranged from 7.9% to 31.2% and from 18.0% to 48.1%, respectively. Ten (5.3%) patients had trough concentrations exceeding 20 mg/L, and 11 (5.8%) had trough concentrations of < or = 3 mg/L. The seven methods studied for estimating vancomycin pharmacokinetic parameters varied widely in predicting vancomycin trough concentrations compared with measured serum concentrations and were not sufficiently reliable to replace therapeutic monitoring of vancomycin serum concentrations.

Aminoglycoside and vancomycin serum concentration monitoring and mortality due to neonatal sepsis in Saudi Arabia.

To assess the effectiveness of monitoring of serum concentration of aminoglycosides in neonates. A retrospective evaluation of serum concentration monitoring of aminoglycosides (gentamicin and amikacin) and vancomycin in neonates treated for sepsis in a maternity and children hospital in Jeddah, Saudi Arabia, over the period 1998-2000. The total number of requests for monitoring increased sixfold in 1999 and 12-fold in 2000 relative to 1998. For aminoglycosides, the incidence of both subtherapeutic peak and toxic trough serum levels decreased significantly (P < 0.05) in 1999 and 2000 compared with 1998. Furthermore, the rate of neonatal mortality caused by sepsis showed reduction in both 1999 (34%) and 2000 (35%) in comparison with 1998 (45%). Vancomycin trough (effective) concentration monitoring revealed no change in the incidence (30%) of levels at subtherapeutic values (<5.0 microg/mL) between the compared years. Furthermore, the rate of toxic levels (>10 microg/mL) increased in both 1999 (31%) and 2000 (39%) relative to 1998 (25%). Therapeutic drug monitoring of vancomycin needs re-evaluation in the hospital to explain why existing methods are ineffective.

Impact of Monitoring Vancomycin Peak and Trough Concentrations versus Trough Concentrations Alone on Dose Adjustments: An Outcomes Analysis

Objective: To determine whether monitoring both steady-state peak and trough serum vancomycin concentrations or steady-state trough serum vancomycin concentrations alone resulted in differences between two groups of patients in terms of dose adjustment, clinical outcome, and toxicity. Design: The study was a retrospective chart review of patients treated with vancomycin during two time periods. Group 1 represented patients hospitalized between July 1, 1996, and January 31, 1997. These patients routinely had vancomycin peak and trough concentrations measured. Group 2 represented patients hospitalized from July 1, 1997, to January 31, 1998, who were monitored with trough vancomycin concentrations only. Setting: A university teaching hospital. Patients: Adults at least 18 years of age who received a constant dose of intravenous vancomycin for at least three consecutive days were eligible for inclusion in the study. Patients were selected from lists generated by the Microbiology Department. The lists contained vancomycin serum concentrations measured during those time frames. Main Outcome Measures: The main outcome measure was to assess whether dose adjustments by prescribers were influenced by both vancomycin peak and trough concentrations or by the trough concentration alone. Results: Forty-nine and 37 patients met the criteria for inclusion into group 1 and group 2, respectively. The mean duration of therapy in group 1 (15 ± 10 d) was not statistically different from that of group 2 (14 ± 12 d). Patients in both groups received a mean daily vancomycin dose of approximately 1,500 mg. In analyzing treatment decisions, trough concentration was the only significant factor influencing a change in total daily dose of vancomycin (p = 0.038). Furthermore, although the method of vancomycin serum concentration monitoring varied between the two groups, the mean clinical outcome parameters were comparable. Conclusions: Prescribers tended to adjust vancomycin regimens based only on trough serum concentrations; monitoring peak serum vancomycin concentrations did not enhance patient care. Mean outcome parameters in the two groups were comparable.

Usefulness of vancomycin serum concentration monitoring in the critically ill patient

Usefulness of vancomycin serum concentration monitoring in the critically ill patient

Predictive performance of a vancomycin-aminoglycoside population model.

To evaluate the Wragge-Cooper method of predicting vancomycin serum concentrations utilizing knowledge of aminoglycoside pharmacokinetic parameters in general medicine and intensive care unit populations, and to develop a revised model if necessary. This study consists of two phases evaluating 50 adults receiving concurrent vancomycin and aminoglycoside therapy. Patients were identified by a retrospective review of medical records. Bayesian analysis of measured serum aminoglycoside and vancomycin concentrations was performed to determine the individualized pharmacokinetic parameters. Phase I of the study tested the predictive performance of a published model incorporating aminoglycoside elimination (Wragge-Cooper) in 25 patients (group 1), and a revised model was developed. Phase II determined the predictive performance of the revised model (revised) and its performance relative to the Wragge-Cooper model and a traditional model incorporating estimated creatinine clearance (traditional) in an additional 25 patients (group 2). Two tertiary care university teaching hospitals. The predictive performance of the models was determined by comparing predicted with measured vancomycin serum concentrations. Bias and precision were evaluated by calculating the mean prediction error (ME) and mean absolute error (MAE), respectively. Linear regression was performed to determine relationships between parameters. The Wragge-Cooper model consistently underpredicts vancomycin serum concentrations in general medicine and intensive care unit populations (ME = -5.18, MAE = 6.63). Relative predictive performance analysis indicates no significant difference in bias or precision between the traditional and Wragge-Cooper models (delta ME 1.17, delta MAE -0.80). Regression analysis of individualized aminoglycoside and vancomycin elimination derived from patients in group 1 reveals the following relationship: vancomycin k10 (1/h) = 0.081 + 1.037ke,amg, r = 0.73. The revised model is significantly less biased and more precise compared with the traditional model (delta ME -4.48; delta MAE 1.22), and is significantly less biased (delta ME 4.29) but no more precise than the Wragge-Cooper model (delta MAE -0.58), using patients from group 2. The revised model is an accurate method of predicting vancomycin serum concentrations in both general medicine and intensive care unit populations. Use of this model enables individualization of vancomycin dosage in patients receiving concurrent aminoglycoside therapy and minimizes vancomycin serum concentration monitoring.

The effect of omeprazole pretreatment on acetaminophen metabolism in rapid and slow metabolizers of S-mephenytoin*

Omeprazole, a widely used and potent gastric proton pump inhibitor, induces cytochrome P450 (CYP) 1A2 in humans. Induction is most pronounced in slow metabolizers of S-mephenytoin because CYP2C19 (S-mephenytoin hydroxylase) is responsible for the elimination of omeprazole. Acetaminophen (INN, paracetamol), a widely used and effective analgesic and antipyretic agent, causes serious hepatic and renal toxicity at high doses by conversion of acetaminophen to the toxic intermediate N-acetyl-p-benzoquinone imine (NAPQI) through CYP1A2, CYP2E1, and CYP3A4. This study evaluated whether omeprazole pretreatment in five rapid and five slow metabolizers of S-mephenytoin could increase thioether (an estimate of NAPQI production) metabolite formation from acetaminophen. The results of this study show that, despite induction of CYP1A2 activity in slow metabolizers (a 75% increase in plasma clearance of caffeine), the formation of NAPQI from acetaminophen was not increased after 7 days of omeprazole administration (40 mg/day). This suggests that induction of CYP1A2 activity by omeprazole is unlikely to increase the risk of acetaminophen hepatotoxicity.

Changes in Vancomycin Pharmacokinetics in Critically Ill Infants

We aimed to assess the pharmacokinetics of vancomycin in critically ill infants, and to evaluate the standard recommended dose of 10 mg/kg 6 hourly. All infants admitted to the Baragwanath Hospital ICU who had arterial lines in situ, and for whom vancomycin 10 mg/kg 6 hourly was prescribed for an infective insult and who had parental consent, were included in the study. Vancomycin was infused over 60 minutes. Serum samples were taken immediately before the dose and at 30, 60, 120 and 300 minutes after the end of the vancomycin infusion, on days 2 and 8 of therapy. Extrapolated peak concentration (Cmax), trough concentration (Cmin), apparent volume of distribution (Vd), elimination half-life (t1/2el) and clearance (CL) were determined for each patient. Day 2 values were compared with those of day 8. Day 2 serum concentrations were assayed on 20 patients and day 8 concentrations in 15. The mean vancomycin Vd on day 2 (0.81 l/kg) was significantly (P = 0.007) larger than that on day 8 (0.44 l/kg). The change in Vd resulted in a significant change in mean Cmax (29.1 vs 35.5 micrograms/ml) (P = 0.02) and mean t1/2el (5.3 vs 3.4h) (P = 0.01) over the treatment period. Critically ill infants displayed a large initial volume of distribution which probably resulted from aggressive fluid resuscitation. This also results in a large variation in other pharmacokinetic parameters, namely Cmax and t1/2el. Although the routine monitoring of vancomycin serum concentrations remain controversial, we feel that in view of these large pharmacokinetic variations, the critically ill infant is a specific group where monitoring of vancomycin serum levels is indicated.

Pharmacokinetic optimisation of vancomycin therapy.

Renewed interest in vancomycin over the past decade has led to an abundance of data concerning the pharmacokinetics of vancomycin, and its dosage selection and concentration-response relationships. No definitive data exist that correlate vancomycin serum concentrations with clinical outcomes. However, inconsistencies in sampling times for peak serum concentrations and differences in infusion times make interpreting vancomycin serum concentrations difficult. Furthermore, the evidence implicating vancomycin as a cause of oto- or nephrotoxicity is circumstantial, and these adverse effects may occur only in high-risk populations. Owing to the variability in its dose-serum concentration relationship and multicompartmental pharmacokinetics, several methodologies have been developed for instituting and adjusting vancomycin dosages. Nomograms rely on a fixed volume of distribution and the relationship between vancomycin clearance and creatinine clearance. Since both of these factors may be altered in certain populations, dosage methodologies (both traditional and Bayesian) that use population- or patient-specific pharmacokinetic data perform better than standard nomograms for initiating vancomycin therapy. Controversy still exists as to whether a 1- or a 2-compartment model is more appropriate for making dosage adjustments; however, steady-state rather than non-steady-state vancomycin serum concentrations should be used for dosage adjustments. Certain pathophysiological states such as age, bodyweight and renal function contribute to altered pharmacokinetics and may alter the design of the dosage regimen. Since no definitive relationship exists between vancomycin serum concentrations and either clinical outcome or adverse effects, considerable controversy surrounds the utility of monitoring serum vancomycin concentrations. Therefore, routine vancomycin serum concentration monitoring may be warranted only in specific populations, such as patients receiving concurrent aminoglycoside therapy or those receiving higher than usual dosages of vancomycin, patients undergoing haemodialysis and patients with rapidly changing renal function.

Rationalization of Vancomycin Serum Concentration Monitoring

ABSTRACT The common practice of adjusting vancomycin dosage based on peak and trough serum levels is examined. To justify the routine monitoring of serum levels of any drug, it must have predictable pharmacokinetics; there must be a correlation between serum levels and effect; and the drug must have a narrow therapeutic index. Peak vancomycin levels are difficult to predict due to the drug's highly variable distribution phase half-life. Since troughs are drawn after distribution is complete, they are readily predictable. Vancomycin's ototoxic potential is doubtful and the incidence of nephrotoxicity is low in patients not receiving concomitant nephrotoxic drugs. There are several studies suggesting that vancomycin may potentiate the nephrotoxicity of other drugs. Trough vancomycin levels greater than 1O mg/L have been correlated to nephrotoxicity; there is no evidence correlating peak levels to ototoxicity or nephrotoxicity. Information relating the efficacy of vancomycin to serum levels is not available. However, based on the minimum inhibitory concentrations for susceptible bacteria and vancomycin's concentration independent killing properties, trough levels between 5 and 10 mg/L would appear adequate. This information suggests that routine monitoring of trough, but not peak, vancomycin serum levels is justified. Initial vancomycin doses should be calculated using available nomograms. Trough vancomycin levels should be maintained between 5 and 10 mg/L by use of dosing nomograms or empiric adjustment. RESUME On a evalue la pratique courante selon laquelle on ajuste la dose de vancomycine selon les concentrations plasmatiques maximales et minimales. Le dosage plasmatique regulier de tout medicament n'est justifie que si sa pharmacocinetique est previsible; s'il existe une correlation entre les concentrations seriques et les effets observes; et si le medicament a une zone therapeutique etroite. Il est difficile de prevoir les pics plasmatiques de la vancomycine parce que sa distribution et sa demi-vie sont grandement variables. Comme les creux plasmatiques sont preleves apres que la vancomycine soit completement distribuee, ils sont donc facilement previsibles. Le risque d'ototoxicite de la vancomycine est discutable et la frequence de nephrotoxicite est faible chez les patients qui ne recoivent pas concurremment d'autres medicaments nephrotoxiques. Les resultats de nombreuses etudes ont laisse croire que la vancomycine pouvait accroitre le potentiel nephrotoxique d'autres medicaments. On a associe la nephrotoxicite a des concentrations plasmatiques minimales superieures a 10 mg/L; on n'a cependant obtenu aucune preuve de correlation entre l'ototoxicite ou la nephrotoxicite et des concentrations plasmatiques maximales. On ne dispose non plus d'aucune information sur le lien entre les concentrations plasmatiques de la vancomycine et l'efficacite de ce medicament. Cependant, en se basant sur les concentrations minimales inhibitrices de la vancomycine pour les bacteries qui y sont sensibles et sur son pouvoir bactericide independant des concentrations, des concentrations minimales entre 5 et 10 mg/L semblent etre suffisantes. Cette information porte a croire que la mesure systematique des concentrations plasmatiques minimales de la vancomycine, et non celle des concentrations maximales, est justifiee. Les doses initiales de vancomycine devraient etre etablies en utilisant les nomogrammes disponibles. Les concentrations minimales devraient etre maintenues entre 5 et 10 mg/L en ayant recours aux nomogrammes ou a l'ajustement empirique de la dose.

Vancomycin Serum Concentration Monitoring: A Continued Debate

Vancomycin Serum Concentration Monitoring: A Continued Debate

Survey of vancomycin monitoring guidelines in Illinois hospitals.

Disparity exists in published recommendations for monitoring of vancomycin serum concentrations. To evaluate the degree of disparity of practice in Illinois, directors of pathology of 202 Illinois hospitals were surveyed to assess their vancomycin monitoring practices. Of the 202 surveys mailed, 82 were returned for a response rate of 41 percent. Most hospitals have 200-500 beds (60 percent) and are nonteaching institutions (72 percent). Two thirds of the hospitals sent vancomycin to an outside laboratory for analysis. Timing of postinfusion (peak) concentrations ranged from 0 minutes following end of infusion to 360 minutes. Approximately one half of the institutions reported a peak therapeutic range of 30-40 mg/L at 30 minutes following end of infusion. A great majority of institutions were consistent in recommended trough range, with 48 of 55 reporting 5-10 mg/L. Although there is some consistency among at least half of the hospitals, there is a great deal of variability among the other half in peak monitoring guidelines.