Prospective Validation of Renal Function–Based Carboplatin Dosing in Children With Cancer: A United Kingdom Children’s Cancer Study Group Trial

2000 ◽  
Vol 18 (21) ◽  
pp. 3614-3621 ◽  
Author(s):  
Huw Thomas ◽  
Alan V. Boddy ◽  
Martin W. English ◽  
Rachel Hobson ◽  
John Imeson ◽  
...  

PURPOSE: Carboplatin dosing in adults with cancer is based on renal function. The purpose of the current study was to validate a previously developed pediatric carboplatin-dosing formula.PATIENTS AND METHODS: Thirty-eight pediatric patients were randomized to receive a carboplatin dose calculated according to surface area or a renal function–based dosing formula. On the next course of therapy, the alternative dosing method was used for each patient. Carboplatin pharmacokinetics (based on free plasma platinum concentrations) were measured after both courses.RESULTS: The mean observed areas under the carboplatin concentration–versus-time curve (AUCs) after renal function– and surface area–based dosing were 98% and 95% of the target AUCs, respectively. The variation in the observed AUC was significantly less after renal function–based dosing (F test, P = .02), such that 74% of courses had an observed AUC within ± 20% of the target value, versus 49% for courses after dosing according to surface area. Only one of 22 courses at the center with the most experience with renal function–based dosing was associated with an AUC outside ± 20% of the target value, versus nine of 22 courses after surface area–based dosing in the same center. There was a relationship (r2= .71) between carboplatin AUC and thrombocytopenia in 10 neuroblastoma patients treated with a combination of carboplatin, vincristine, etoposide, and cyclophosphamide.CONCLUSION: Renal function–based carboplatin dosing in children results in more consistent drug exposure than surface area–based drug administration.

2001 ◽  
Vol 40 (04) ◽  
pp. 107-110 ◽  
Author(s):  
B. Roßmüller ◽  
S. Alalp ◽  
S. Fischer ◽  
S. Dresel ◽  
K. Hahn ◽  
...  

SummaryFor assessment of differential renal function (PF) by means of static renal scintigraphy with Tc-99m-dimer-captosuccinic acid (DMSA) the calculation of the geometric mean of counts from the anterior and posterior view is recommended. Aim of this retrospective study was to find out, if the anterior view is necessary to receive an accurate differential renal function by calculating the geometric mean compared to calculating PF using the counts of the posterior view only. Methods: 164 DMSA-scans of 151 children (86 f, 65 m) aged 16 d to 16 a (4.7 ± 3.9 a) were reviewed. The scans were performed using a dual head gamma camera (Picker Prism 2000 XP, low energy ultra high resolution collimator, matrix 256 x 256,300 kcts/view, Zoom: 1.6-2.0). Background corrected values from both kidneys anterior and posterior were obtained. Using region of interest technique PF was calculated using the counts of the dorsal view and compared with the calculated geometric mean [SQR(Ctsdors x Ctsventr]. Results: The differential function of the right kidney was significantly less when compared to the calculation of the geometric mean (p<0.01). The mean difference between the PFgeom and the PFdors was 1.5 ± 1.4%. A difference > 5% (5.0-9.5%) was obtained in only 6/164 scans (3.7%). Three of 6 patients presented with an underestimated PFdors due to dystopic kidneys on the left side in 2 patients and on the right side in one patient. The other 3 patients with a difference >5% did not show any renal abnormality. Conclusion: The calculation of the PF from the posterior view only will give an underestimated value of the right kidney compared to the calculation of the geometric mean. This effect is not relevant for the calculation of the differntial renal function in orthotopic kidneys, so that in these cases the anterior view is not necesssary. However, geometric mean calculation to obtain reliable values for differential renal function should be applied in cases with an obvious anatomical abnormality.


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 2521-2521 ◽  
Author(s):  
S. G. Poole ◽  
M. J. Dooley ◽  
D. Rischin

2521 Background: The dose of carboplatin is usually calculated using the Calvert formula, with various bedside estimates utilized rather than directly measured GFR. The 4-v MDRD equation (Levey AS, et al. Ann Intern Med 2006; 145: 247–254) is now advocated as the routine method of estimating renal function from serum creatinine in all patients. Adoption in clinical practice is occurring despite lack of validation in oncology patients. The aim of this study was to compare carboplatin doses derived from the Calvert formula using measured GFR and the estimates of the 4-v MDRD equation and other established estimates. Methods: GFR was determined using technetium-99m diethyl triamine penta-acetic acid (Tc99mDTPA) clearance. Serum creatinine (Jaffe method) was measured and GFR estimates calculated using 4-v MDRD, Cockcroft and Gault formula (CGF), Wright, Martin, and Jelliffe (JF) formulae. Carboplatin doses were calculated using the Calvert formula, targeting an area under the curve of 7mg.ml- 1.min-1. Results: GFR was measured in 510 adult oncology patients (323 male, 187 female, mean age 63 years, range 17–87 years, mean GFR 84 mL/min, range 16–205 mL/min). The mean (range) carboplatin dose was 765 mg (287–1,610 mg), 681 mg (237–1,306 mg), 674 mg (249–2,044 mg), 721 mg (261–1,536mg), 741 mg (261–2,128mg), 620 mg (244- 1,329 mg) for measured GFR, 4-v MDRD, CGF, Wright, Martin, and JF formulas respectively. The accuracy (% within 20% of ‘true’ dose) was 58%, 63%, 73%, 72% and 49% for 4-v MDRD, CGF, Wright, Martin, and JF formulas respectively. Carboplatin doses derived using the 4-v MDRD estimate of GFR become increasingly less accurate with increasing GFR (see table ). All other formulas performed similarly. Conclusions: The 4-v MDRD equation resulted in an imprecise estimation of carboplatin doses with the degree of variability dependant on the level of renal function. [Table: see text] No significant financial relationships to disclose.


1996 ◽  
Vol 40 (8) ◽  
pp. 1866-1869 ◽  
Author(s):  
J G Gillum ◽  
J M Sesler ◽  
V L Bruzzese ◽  
D S Israel ◽  
R E Polk

Rifampin and rifabutin induce the metabolism of many drugs, which may result in subtherapeutic concentrations and failure of therapy. However, differences between rifabutin and rifampin in potency of induction, and the specific enzymes which are altered, are not clear. This study, involving 12 adult male volunteers, compared the effects of 14-day courses of rifampin and rifabutin on clearance of theophylline, a substrate for the hepatic microsomal enzyme CYP1A2. Subjects were given oral theophylline solution (5 mg/kg of body weight) on day 1 and then randomized to receive daily rifampin (300 mg) or rifabutin (300 mg) on days 3 to 16. Theophylline was readministered as described above on day 15. The first treatment sequence was followed by a 2-week washout period; subjects then received the alternative treatment. Theophylline concentrations were determined for 46 h after each dose, and pharmacokinetic parameters were determined. One subject developed flu-like symptoms while taking rifabutin and withdrew voluntarily. Results from the remaining 11 subjects are reported. Compared with the baseline, the mean area under the concentration-time curve (AUC) (+/- standard deviation) for theophylline declined significantly following rifampin treatment (from 140 +/- 37 to 100 +/- 24 micrograms . h/ml, P <0.001); there was no significant change following rifabutin treatment (136 +/- 48 to 128 +/- 45 micrograms.h/ml). Baseline theophylline AUCs before each treatment phase were not different. A comparison of equal doses of rifampin and rifabutin administered to healthy volunteers for 2 weeks indicates that induction of CYP1A2, as measured by theophylline clearance, is significantly less following rifabutin treatment than it is following rifampin treatment. However, the relative induction potency for other metabolic enzymes remains to be investigated.


1996 ◽  
Vol 40 (3) ◽  
pp. 696-700 ◽  
Author(s):  
J K James ◽  
S M Palmer ◽  
D P Levine ◽  
M J Rybak

Ten patients were treated with conventional dosing (CD) and continuous-infusion (CI) vancomycin therapy in this prospective, randomized, crossover study. Patients were randomized to receive either CD or CI therapy for 2 consecutive days and then crossed over to receive the opposite regimen for 2 days. CD therapy consisted of 1 g of vancomycin every 12 h. CI therapy consisted of a 500-mg loading dose followed by 2 g infused over 24 h. Ten serum samples were obtained on the second day of each therapy for pharmacokinetic and pharmacodynamic analyses. Two clinical isolates of Staphylococcus aureus, one methicillin sensitive (MSSA 1199) and one methicillin resistant (MRSA 494), were chosen for pharmacodynamic evaluation of both regimens. The patient demographics (means +/- standard deviations [SD]) were as follows: sex, six males, four females; age, 36 +/- 11 years; and serum creatinine, 0.72 +/- 0.18 mg/dl. Mean pharmacokinetic parameters +/- SD for CD therapy were as follows: elimination rate constant, 0.16 +/- 0.07 h-1; half-life, 5.6 +/- 3.5 h; volume of distribution, 33.7 +/- 25 liters, 0.5 +/- 0.2 liters/kg; maximum concentration in serum, 53.4 +/- 19.3 micrograms/ml; and minimum concentration, 8.4 +/- 5.9 micrograms/ml. The steady-state concentration for CI was 20.2 +/- 11.1 micrograms/ml. Overall, both regimens resulted in the MIC being exceeded 100% of the time. The mean CD trough serum bactericidal titer (SBT) was 1:8, and the average CI SBTs were 1:16 for both isolates. Even though there was no statistically significant difference between CD trough and CI SBTs, the CI SBTs remained > 1:8 for 100% of the time versus 60% of the time for CD therapy. During CI therapy, 20 and 40% of the patients maintained SBTs of > 1:32 throughout the dosing interval for MSSA 1199 and MRSA 494, respectively. During CD therapy, however, only 10% of patients maintained SBTs of > 1:32 during the entire dosing interval for both isolates. The mean areas under the bactericidal titer-time curve (AUBC24s) +/- SD for MSSA 1199 were 528 +/- 263 for CD therapy and 547 +/- 390 for CI therapy. The mean AUBC24s +/- SD against MRSA 494 were 531 +/- 247 for CD and 548 +/- 293 for CI therapy. Similar to the AUBC24, the mean area under the concentration-time curve for a 24-h dosing interval divided by the MIC (AUC/MIC24) ratios +/- SD were 550.0 +/- 265.7 for CD and 552.6 +/- 373.4 for CI therapy, respectively. No statistically significant differences were found between any of the pharmacodynamic parameters for CD and CI therapy. In addition, no adverse effects with either CD or CI therapy were observed during the study. We conclude that CI and CD vancomycin therapy demonstrated equivalent pharmacodynamic activities. Although CI therapy was more likely to result in SBTs that remained above 1:8 for the entire regimen, the clinical impact of this result is unknown. Serum drug concentration variability was observed with both treatment regimens but to a lesser extent with CI administration. CI administration of vancomycin should be further evaluated to determine the clinical utility of this method of administration.


1998 ◽  
Vol 42 (4) ◽  
pp. 821-826 ◽  
Author(s):  
John M. Adams ◽  
Mark J. Shelton ◽  
Ross G. Hewitt ◽  
Thaddeus H. Grasela ◽  
Mary DeRemer ◽  
...  

ABSTRACT We used information available from routine clinic visits to characterize the pharmacokinetics of didanosine in 82 human immunodeficiency virus-infected patients. A total of 271 blood samples were collected for the measurement of didanosine concentrations in plasma (mean ± standard deviation [SD], 3.30 ± 2.21 samples/patient). Bayesian estimates of didanosine oral clearance (CLoral) were obtained for these patients by the POSTHOC option within the NONMEM software package. Population priors from a previous NONMEM analysis of didanosine pharmacokinetics were used. The mean ± SD CLoral was 132 ± 27.7 liters/h, which agrees reasonably well with estimates obtained from previous pharmacokinetic studies of didanosine. Estimates of individual didanosine exposure were then used to consider potential relationships between drug exposure and surrogate marker response over a 6-month period. No correlations were found between the didanosine area under the concentration-time curve from 0 to 6 months and the absolute CD4 cell count (r = 0.305; 0.1 <P < 0.2), weight response (r = 0.0857; P > 0.4), or percentage of CD4 lymphocytes (r = 0.0559; P > 0.4). Future efforts to characterize didanosine exposure in outpatients by random sampling methods should involve more directed efforts to limit residual variability in the data.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2239-2239
Author(s):  
Hermann Einsele ◽  
Pierre Reusser ◽  
Holger Hebart ◽  
Bernd Hertenstein ◽  
Martin Bornhaeuser ◽  
...  

Abstract Background: After alloSCT, oral valganciclovir (VALGCV) is a promising alternative to IV GCV against CMV but its pharmacokinetics (PK) have not been studied. Methods: We investigated the PK of GCV after VALGCV in a randomized, crossover phase II-study of 48 patients (pts) after alloSCT. Pts who had >400 copies/ml of CMV DNA in plasma measured by quantitative PCR were randomized to receive a fixed dose of VALGCV 900 mg BID (adjusted for renal function) for 7 days, followed by IV GCV as 1-h-infusion at 5mg/kg every 12 h for another 7 days, or to receive the inverse sequence of study drug administration. The PK of GCV were assessed on days 4 and 11. Safety monitoring was done until day 84 after alloSCT. Results: 28 pts were fully assessable for PK analyses. Among the 22 pts without intestinal graft-versus-host disease (GVHD), the mean±SD AUC 0–12 (mg/L*h) was 53.8±18.0 on VALGCV vs 39.5±13.9 on IV GCV (mean difference 14.3 [95% CI 7.6 to 20.9]); Cmax (mg/L) was 8.8±2.4 vs 10.3±2.1; tmax was 2.7±0.8 vs 1.1±0.6; and t1/2 was 4.2±1.1 vs 3.4±0.8. Among the 6 pts with intestinal GVHD, the mean±SD AUC 0–12 (mg/L*h) was 46.6±24.9 on VALGCV vs 35.3±12.8 on IV GCV (mean difference 11.3 [95% CI −13.4 to 35.9]); Cmax (mg/L) was 7.1±3.6 vs 11.1±3.1; tmax (h) was 2.7±0.8 vs 1.2±0.4; and t1/2 (h) was 5.6±2.0 vs 3.3±0.7. The bioavailability of GCV after VALGCV was 53%. Using a VALGCV fixed oral dose (1.800mg) for preemptive therapy in pts with low body weight led to a sharp increase of the VALGCV / IV GCV ratio (i.e. 50kg = 1.9). With a limited number of pts with low body weight included in this study no severe GCV associated toxicity was seen in these pts. Non-fatal CMV pneumonia developed in 2 pts during follow-up after antiviral therapy, and servere neutropenia < 500/μl occurred in 3 pts. Clearance of CMV DNA was equally effective in both arms. Conclusions: In alloSCT, exposure to GCV after preemptive therapy using VALGCV is higher compared to that with IV GCV in patients with and without intestinal GVHD. In addition to patients with renal dysfunction patients with low body weight < 60kg and normal renal function should be treated very carefully to avoid over-exposure to GCV. Although no severe toxicity was demonstrated in this pk-study a further study to address the safety and efficacy of VALGCV in alloSCT is needed.


1999 ◽  
Vol 43 (6) ◽  
pp. 1516-1519 ◽  
Author(s):  
Leock Y. Ngo ◽  
Ram Yogev ◽  
Wayne M. Dankner ◽  
Walter T. Hughes ◽  
Sandra Burchett ◽  
...  

ABSTRACT To evaluate if atovaquone (ATQ) interacts pharmacokinetically with azithromycin (AZ) in human immunodeficiency virus-infected children, 10 subjects (ages, 4 to 13 years) were randomized in a crossover study to receive AZ (5 mg/kg/day) alone (ALONE) or AZ (5 mg/kg/day) and ATQ (30 mg/kg/day) simultaneously (SIM) prior to receiving AZ and ATQ staggered by 12 h. Despite a lack of significant difference in the mean AZ pharmacokinetic parameters, the steady-state values of AZ’s area under the concentration-time curve from 0 to 24 h and maximum concentration in serum were consistently lower (n = 7 of 7) for the SIM regimen than they were for the ALONE regimen. A larger study will be required to determine if ATQ affects AZ pharmacokinetics and efficacy in a clinically significant manner.


2014 ◽  
Vol 59 (2) ◽  
pp. 1246-1251 ◽  
Author(s):  
Wendy M. Kersemaekers ◽  
Thijs van Iersel ◽  
Ulla Nassander ◽  
Edward O'Mara ◽  
Hetty Waskin ◽  
...  

ABSTRACTThis study evaluated the safety, tolerability, and pharmacokinetics of a posaconazole i.v. (intravenous) solution. This was a single-center, 2-part, randomized, rising single- and multiple-dose study in healthy adults. In part 1, subjects received 0 (vehicle), 50, 100, 200, 250, or 300 mg posaconazole in a single dose i.v. by 30-min peripheral infusion (6 cohorts of 12 subjects each [9 active and 3 placebo], making a total of 72 subjects). Blood samples were collected until 168 h postdose. In part 2, subjects were to receive 2 peripheral infusions at a 12-h interval on day 1 followed by once-daily infusion for 9 days. However, part 2 was terminated early because of high rates of infusion site reactions with multiple dosing at the same infusion site. The pharmacokinetics results for part 1 (n= 45 subjects) showed that the mean posaconazole exposure (area under the concentration-time curve from time zero to infinity [AUC0–∞]) ranged from 4,890 to 46,400 ng · h/ml (range of coefficient of variation values, 26 to 50). The dose-proportionality slope estimate (90% confidence interval) for AUC0–∞was 1.30 (1.19 to 1.41), indicating a greater-than-dose-proportional increase. The data for safety in part 1 show that 29/72 subjects had ≥1 adverse event. Infusion site reactions were reported in 2/9 vehicle subjects, 0/18 placebo subjects, and 7/45 i.v. posaconazole subjects. The data for safety in part 2 show that infusion site reactions were reported in 1/4 (25%) placebo subjects, 3/9 (33%) vehicle control subjects, and 4/5 (80%) i.v. posaconazole (100 mg) subjects (3 posaconazole recipients subsequently developed thrombophlebitis and were discontinued from treatment). In conclusion, the posaconazole i.v. solution showed a greater-than-dose-proportional increase in exposure, primarily at doses below 200 mg. When administered peripherally at the same infusion site, multiple dosing of i.v. posaconazole led to unacceptably high rates of infusion site reactions. Intravenous posaconazole was otherwise well tolerated. Single doses of i.v. posaconazole were tolerated when given through a peripheral vein over 30 min.


2019 ◽  
Vol 63 (10) ◽  
Author(s):  
Richard A. Preston ◽  
Grigor Mamikonyan ◽  
Mushtaque Mastim ◽  
Dyal Garg ◽  
Christopher J. Kemper ◽  
...  

ABSTRACT WCK 4282 is a combination product of cefepime (FEP) and tazobactam (TAZ) in a 1:1 ratio currently under development for the treatment of multidrug-resistant Gram-negative bacterial infections. We investigated the effect of renal impairment on the pharmacokinetics (PK) and safety of WCK 4282 in 48 subjects with various degrees of renal function. Subjects were categorized on the basis of their Cockcroft-Gault equation-estimated creatinine clearance (CLCR). We enrolled 6 subjects each into those with mild (CLCR, 60 to <90 ml/min), moderate (CLCR, 30 to <60 ml/min), or severe (CLCR, <30 ml/min) renal impairment and those with end-stage renal disease (ESRD) requiring hemodialysis and 24 healthy control subjects (CLCR, ≥90 ml/min). Healthy subjects and subjects with mild and moderate renal impairment received a single 90-min infusion of 4 g of WCK 4282 (2 g FEP and 2 g TAZ). Subjects with severe renal impairment and ESRD received 2 g of WCK 4282 (1 g FEP and 1 g TAZ) over 90 min. The plasma exposure of FEP-TAZ increased as renal function decreased. In subjects with mild, moderate, and severe renal impairment and ESRD, the mean exposure (area under the plasma concentration versus time curve from time zero extrapolated to infinity) of FEP and TAZ increased by 1.3- and 1.2-fold, 2.3- and 2.3-fold, 4.7- and 4.0-fold, and 8.5- and 11.6-fold, respectively. The urinary recovery of FEP and TAZ decreased with increasing renal impairment. There were no adverse events reported during the study. The findings suggest that dose adjustments for WCK 4282 will be required according to the degree of renal impairment. A single infusion of WCK 4282 was found to be safe and well tolerated in subjects with normal and impaired renal function. (This study has been registered at ClinicalTrials.gov under identifier NCT02709382.)


2016 ◽  
Vol 47 (4) ◽  
pp. 1229-1234 ◽  
Author(s):  
Sander P. van Rijn ◽  
Richard van Altena ◽  
Onno W. Akkerman ◽  
Dick van Soolingen ◽  
Tridia van der Laan ◽  
...  

Treatment of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) is becoming more challenging because of increased levels of drug resistance against second-line TB drugs. One promising group of antimicrobial drugs is carbapenems. Ertapenem is an attractive carbapenem for the treatment of MDR- and XDR-TB because its relatively long half-life enables once-daily dosing.A retrospective study was performed for all patients with suspected MDR-TB at the Tuberculosis Center Beatrixoord of the University Medical Center Groningen (Haren, the Netherlands) who received ertapenem as part of their treatment regimen between December 1, 2010 and March 1, 2013. Safety and pharmacokinetics were evaluated.18 patients were treated with 1000 mg ertapenem for a mean (range) of 77 (5–210) days. Sputum smear and culture were converted in all patients. Drug exposure was evaluated in 12 patients. The mean (range) area under the concentration–time curve up to 24 h was 544.9 (309–1130) h·mg·L−1. The mean (range) maximum observed plasma concentration was 127.5 (73.9–277.9) mg·L−1.In general, ertapenem treatment was well tolerated during MDR-TB treatment and showed a favourable pharmacokinetic/pharmacodynamic profile in MDR-TB patients. We conclude that ertapenem is a highly promising drug for the treatment of MDR-TB that warrants further investigation.


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