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1.
Etoposide phosphate is a water-soluble prodrug of etoposide. The plasma pharmacokinetics of etoposide following oral administration of etoposide phosphate or oral etoposide were compared. Seventeen patients with solid tumours were enrolled to receive oral etoposide phosphate 125 mg m(-2) on days 1-5 every 3 weeks, with escalation to 175 mg m(-2) from course 3 when possible. Patients were randomized to receive oral etoposide phosphate or oral etoposide on day 1 of course 1 and the alternative compound on day 1 of course 2. Fifteen patients received two or more courses and were evaluable for pharmacokinetic comparisons. The median AUC(inf) (area under the concentration vs time curve from zero to infinity) of etoposide was 77.7 mg l(-1) h after etoposide phosphate (95% CI 61.3-100.5) and 62.0 mg l(-1) h after oral etoposide (95% CI 52.2-76.9). The difference in favour of etoposide phosphate was borderline significant: median 9.9 mg l(-1) h (95% CI 0.1-32.8 mg l(-1) h; P = 0.05). However, the inter-patient variability of etoposide AUC(inf) was not improved (coefficients of variation 42.3% and 48.4%). Etoposide phosphate was undetectable in plasma after oral administration. Toxicities of oral etoposide phosphate were not different from those known for etoposide. In conclusion, oral etoposide phosphate does not offer a clinically relevant benefit over oral etoposide.  相似文献   

2.
We previously established a limited sampling model (LSM) for the area under the concentration versus time curve (AUC) of irinotecan (CPT-11). Using this LSM, we performed a pharmacokinetic-pharmacodynamic analysis of CPT-11 in a multicentric Phase II study for non-small cell lung cancer. Ten institutes participated in this study, 36 patients were registered, and 30 patients were evaluable for the pharmacokinetic-pharmacodynamic analysis. CPT-11 and etoposide were administered daily for three consecutive days, both at a dose of 60 mg/m2. Blood samples were obtained 4 and 8 h after infusion on days 1 and 3. When using the LSM, there is a significant possible source of error in the timing of these selected points. In this study, however, the sample timing error was small. Mean timing errors were 1.0-4.0 min at each point. The estimated CPT-11 AUCs were: Day 1 Day 2 Day 1 + 3 Mean +/- SD (mg.h/liter) 3.76+/-0.68 4.10+/-0.86 7.86+/-1.43 Range 2.01-5.03 2. 29-5.72 4.30-10.68 Max/min 2.50 2.45 2.48 High interpatient variability was observed in the AUC. The CPT-11 AUC correlated positively with the grade of emesis (P = 0.003) and the percent decreases in WBC count (P = 0.001) and absolute neutrophil count (P =0.0006), but it did not correlate with the grade of diarrhea or response. We concluded that the LSM was useful in estimating individual pharmacokinetic parameters in multicentric trials.  相似文献   

3.
The toxicity and therapeutic activity, including the effect on quality of life, of the carboplatin-oral etoposide combination, given with an intrapatient dose escalation, was tested in 38 non-small cell lung cancer (NSCLC) patients aged over 70 years, and in 8 younger patients with a performance status of 2. In the absence of grade 3-4 toxicity, doses were escalated as follows: first course (carboplatin AUC 4; etoposide 50 mg twice daily orally days 1-14); second course (carboplatin AUC 5; etoposide 50 mg twice daily orally days 1-14); third course (carboplatin AUC 5; etoposide 50 mg twice daily orally days 1-21). A total of 141 chemotherapy cycles were delivered. The treatment was, in general, well tolerated and no toxic deaths occurred. More than 60% of patients received 100% of the planned dose intensity. Transient grade 4 neutropenia or thrombocytopenia occurred in 6 and 2 patients, respectively, but only 2 patients had to be hospitalised because of fever. All patients were evaluated for activity on an 'intention to treat basis'. Ten partial responses and 20 stable disease were recorded, for an overall response rate of 22% (95% confidence interval (CI) = 11-36). 9/38 (24%; 95% CI = 12-41) elderly patients obtained a partial response. The median response duration was 4 months. A quality of life improvement was observed in 19 of the 46 enrolled patients (41%; 95% CI = 27-57), and 15/46 (33%; 95% CI = 19-48) showed a performance status improvement. The quality of life score improved in 17/38 (45%) elderly patients. 8/10 responders and 11/20 patients with stable disease showed a concomitant improvement in quality of life. At a median potential follow-up of 16 months (range 2-21), 31 patients had had progression of disease and 23 had died, for a median time to progression (TTP) and overall survival (OS) of 5 and 10 months, respectively. The median survival time was 11 months in the elderly patients. The median time to subjective impairment (TSI) was 6 months (7 months in the elderly group). One-year estimated TTP, TSI and OS rates were 22, 29 and 41%, respectively. At multivariate Cox analysis, a > 25% improvement in the quality of life score was more predictive of a better survival outcome than the response achievement.  相似文献   

4.
Therapeutic monitoring of cyclosporine (CsA) by using area-under-the-concentration-time-curve (AUC) values in renal transplant recipients has been previously demonstrated to predict posttransplant clinical outcome. Two previous studies also reported that limited sampling equations could accurately determine the AUC of CsA using one to six blood concentration determinations in adults. The purpose of this study was to validate the accuracy of these equations in a pediatric population. In 18 pediatric patients who received renal allografts, three limited sampling equations, which used one, four, or five concentration time points, accurately estimated CsA AUC when compared with an actual 7- to 9-point curve. An equation that used a single concentration time point at 5 hours was unbiased and provided the best precision in calculating a 12-hour interval AUC. This equation had a mean absolute percentage error of 5.8% (95% confidence interval, 3.3 to 8.3). Equations using four or five concentration time points were found to provide estimates of AUC for a 24-hour interval AUC, with less than 10% error. These findings suggest that limited sampling models using as few as one to four concentration time points provide accurate estimations of CsA AUC in pediatric patients. The use of these limited sampling models provides the clinical advantage of lower blood sampling requirements and reduced costs associated with the monitoring of cyclosporine.  相似文献   

5.
PURPOSE: To determine the response rate and survival of chemotherapy-naive patients with extensive-stage small-cell lung cancer (SCLC) treated with topotecan, and to determine the relationship of topotecan pharmacokinetics with response and toxicity. PATIENTS AND METHODS: Forty-eight patients with previously untreated, extensive-stage SCLC received 2.0 mg/m2 of topotecan daily for 5 days. The first 13 patients were treated without colony-stimulating factor (CSF) support; the next 35 patients received 5 micrograms/kg of granulocyte-colony-stimulating factor (G-CSF) for 10 to 14 days starting on day 6. Cycles were repeated every 3 weeks for a maximum of four cycles. Patients who had a partial response to topotecan after four cycles, stable disease after two cycles, or progressive disease at any time received salvage chemotherapy with cisplatin and etoposide. Topotecan pharmacokinetics were measured using a four-point sampling scheme. RESULTS: Of 48 patients, none had a complete response and 19 had a partial response, for an objective response rate of 39% (95% confidence interval [CI], 25.2% to 53.0%). The median response duration was 4.8 months (95% CI, 3.0 to 7.3). After a median follow-up duration of 18.2 months, the overall median survival time was 10.0 months (95% CI, 8.2 to 12.7); the 1-year survival rate was 39% (95% CI, 25.2% to 53.0%). Eight of 34 patients (24%) who received salvage chemotherapy responded. Four of 17 patients who did not respond to first-line therapy with topotecan responded to cisplatin and etoposide. The most common toxicity was hematologic. Ninety-two percent of patients treated without G-CSF developed grade 3 or 4 neutropenia, compared with 29% who received G-CSF. However, the incidence of neutropenic fevers was similar between the two groups (8% and 11%, respectively), and one patient in each group died of neutropenic fevers. There were no differences in objective tumor response, duration of response, time to treatment failure, or survival between the 13 patients who entered the study before G-CSF administration was mandated and the 35 patients who entered after and received G-CSF. There was poor correlation between the WBC count and absolute neutrophil counts (ANCs) and both the area under the curve (AUC) and maximum concentration++ (Cmx) of total topotecan in plasma. There was no correlation between the tumor response and either AUC or Cmx of total topotecan. CONCLUSION: The activity of topotecan in extensive-stage SCLC noted in this study warrants further investigation of this agent in phase III clinical trials.  相似文献   

6.
We aimed to evaluate the pharmacokinetics and pharmacodynamics of etoposide given chronically by the p.o. route to patients with small cell and non-small cell lung cancer. Single daily p.o. doses of 100 mg etoposide were given for 21 consecutive days every 4 weeks to 39 previously untreated patients with small cell lung cancer and 10 patients with non-small cell lung cancer. Bioavailability was studied after one i.v. and one p.o. dose of 100 mg etoposide given 48 h before and on day 1 of treatment, respectively. Etoposide plasma levels were measured using the HPLC method. Inter- and intrapatient variability of the area under the curve of the concentration versus time (AUC) during the first cycle were evaluated using a limited sampling model; the variability of etoposide plasma concentrations (Ecs) during the first cycle was assessed by weekly blood samples taken 24 h after dosing. The overall bioavailability of etoposide (mean +/- SD) was 67% +/- 22% and was not affected by fasting. A much higher inter- than intrapatient variability of both the AUC and 24-h Ec determined on days 8, 15, and 22 was found. Neutropenia was dose limiting and of varying degrees (mean +/- SD of absolute neutrophil count nadir at the first cycle: 1.5 +/- 1.2 x 10(3)/microliter). Neutropenia WHO grade >/=3 occurred in 38% of the patients after the first cycle. Pharmacodynamic analyses showed a significant relationship between the mean 24-h Ec and neutropenia, expressed as log- of absolute neutrophil count nadir or as a relative decrease of neutrophils. A correlation between a critical value of mean 24-h Ec (0.34 microgram/ml) and a high probability of achieving a greater than 80% decrease in absolute neutrophil count was found. Two pharmacodynamic models (one previously described and one developed in this study) were used to evaluate the possibility of predicting neutropenia on the basis of individual etoposide pharmacokinetics and baseline absolute neutrophil count. Pharmacokinetic studies have shown a high interpatient variability and a relatively low intrapatient variability of AUC and 24-h Ec. The application of the pharmacodynamic models and mean 24-h Ec cutoff values has proven statistically valid to predict the occurrence of severe neutropenia. However, it remains to be demonstrated in a prospective manner whether the application of pharmacokinetic/ pharmacodynamic knowledge can improve the overall therapeutic outcome of chronic p.o. treatment with etoposide.  相似文献   

7.
BACKGROUND: The safety and efficacy of idarubicin, etoposide, and carboplatin as remission induction therapy for patients younger than 60 years with untreated acute myeloid leukemia was studied as an alternative to standard regimens based on cytarabine plus anthracycline. METHODS: Eligible patients received idarubicin (36-40 mg/m2), etoposide (500 mg/m2), and carboplatin (1000-1500 mg/m2) over 5 days. Those who achieved complete remission received a single course of cytarabine 1.5 gm/m2 every 12 hours for a total of 12 doses. D-xylose absorption was studied as a marker for cytotoxic therapy-induced gut mucosal damage. Cytogenetic and immunophenotyping studies were performed at the time of diagnosis and examined for prognostic importance. RESULTS: Remission was achieved in 29 (67%) of 43 patients with a single induction course. The median leukemia free and overall survival times were 15.4 months (95% CI 6.5-24.2) and 12.5 months (95% CI 5.9-19.1), respectively. Induction mortality was 14%. Karyotype (normal, simple, or complex vs. very complex) was the strongest predictor of remission (79% vs. 25%, P=0.01), leukemia free survival (odds ratio [OR] 19.3, 95% CI 2.7-138.9), and overall survival (OR 5.4, 95% CI 2.1-13.9). Dose-limiting gut mucosal toxicity was greatest during Weeks 2 and 3. Bloodstream infections occurred in 49% of patients at a median of 12 days. Grade 3-4 diarrhea, nausea, stomatitis, esophagitis/dysphagia, and vomiting developed in 33%, 26%, 23%, 9%, and 2% of cases, respectively, at a median of 17, 16, 11, 15.5, and 21 days, respectively. CONCLUSIONS: This regimen was active in adults younger than 60 years with untreated acute myeloid leukemia and normal, simple, or complex karyotypes. Remission duration was confounded by karyotype. Mucosal toxicity limited the tolerability of this regimen. These adverse effects might be overcome by increasing the intensity of postremission therapy and modifying the dosing schedule.  相似文献   

8.
OBJECTIVE: This study was undertaken in order to evaluate the impact of pharmacokinetics on the toxicity of oral etoposide administered daily for 21 days. METHODS: The daily dose was 50 mg/m2. Thirty-two patients 24 males and eight females, 36 76 years old, treated for various tumour types), were evaluated. Blood samples were obtained on day 1 for all patients, and on day 21 for 16 patients. Plasma etoposide concentrations were determined by high-performance liquid chromatography, and etoposide plasma protein binding by equilibrium dialysis. RESULTS: On day 1, the mean value (with coefficient of variation for interindividual variability) for the unbound fraction (fu), area under the concentration versus time curve (AUC), and unbound AUC was 9.8% (59%), 34 mg x h/l (39%), and 3.5 mg x h/l (92%), respectively. The ratio between AUC on day 1 and day 21 ranged between 0.5 and 1.8 (mean 0.9, with CV 33%). The plasma trough unbound concentrations and the unbound AUCs both corresponding to the first administration were significantly higher in the 11 patients who had a severe neutropenia than in the 21 patients who had no or moderate toxicity. However, total etoposide concentrations did not differ between these two groups. A limited sampling strategy using the NONMEM program and a database of 89 patients previously studied was performed. The optimal sampling schedule (i.e. 1, 4, and 24 h after oral etoposide administration) allowed to obtain the AUC accurately on day 1. CONCLUSION: Individual adjustment of oral etoposide based on unbound pharmacokinetics after the first administration appears relevant and feasible.  相似文献   

9.
This open-label, non-randomized, parallel-group trial investigated the pharmacokinetics of raltitrexed (Tomudex, formerly ZD1694) after a single intravenous dose of 3.0 mg m(-2), comparing eight cancer patients with mild to moderate renal impairment (creatinine clearance 25-65 ml min(-1)) with eight cancer patients with normal renal function (creatinine clearance >65 ml min(-1)). The primary end points were area under the plasma raltitrexed concentration-time curve from the start of the infusion to the last determined concentration (AUC(0-tldc)) and AUC to infinity (AUC(0-infinity)); secondary end points were peak concentrations of raltitrexed (Cmax) and elimination half-life (t(1/2gamma)). The groups were compared statistically using analysis of covariance. The AUCs were greater for patients with renal impairment than for patients with normal renal function (2452.2 compared with 1247.3 ng h ml(-1) for AUC(0-tldc) (ratio 1.97; 95% CI 1.36-2.84); 2961.5 compared with 1457.0 ng h ml(-1) for AUC(0-infinity) (ratio 2.03; 1.25-3.29). These differences were statistically significant (P = 0.002 and P = 0.008 for AUC(0-tldc) and AUC(0-infinity) respectively. Terminal half-life was longer for the renally impaired patients (271.2 compared with 143.3; P = 0.030). There was no significant statistical difference between the groups for Cmax (652.9 compared with 564.7 ng ml(-1) for patients with impaired and normal renal function respectively: ratio 1.16; 0.91-1.46; P = 0.204). There was a clear relationship between raltitrexed clearance and creatinine clearance. Adverse events, severe (WHO grade 3 or 4) toxicity and hospitalization due to adverse events were more frequent in the group with renal impairment. Therefore, a reduction in raltitrexed dose and increased interval between doses is recommended for patients with mild to moderate renal impairment.  相似文献   

10.
OBJECTIVE: To determine the minimal clinically significant difference (MCSD) on a visual analog patient satisfaction scale. METHODS: The authors prospectively collected patient satisfaction evaluations during a clinical trial assessing the effect of introducing personal television sets on overall patient satisfaction from their ED encounters. Patient satisfaction was assessed with 2 scales: a 100-mm visual analog scale (VAS) (0 = least satisfied, 100 = most satisfied) and a 7-point categorical scale ("terrible," "mostly dissatisfied," "mixed," "partially satisfied," "mostly satisfied," "pleased," and "delighted"). The differences between the mean VAS scores of "delighted" and "pleased" patients, and between "pleased" and "mostly satisfied" patients were used to determine the MCSD on the VAS. Reliability of each of the scales was determined. RESULTS: 181 patients were evaluated. Mean age was 41 years; 59% were female. On a subset of 19 patients, the VAS yielded an interobserver correlation of 0.93. The kappa measurement of agreement on the categorical scale was 0.77. The mean difference between "delighted" and "pleased" patient VAS satisfaction scores was 6.8 mm (95% CI, 1.3-12.3 mm). The mean difference between "pleased" and "mostly satisfied" patient VAS satisfaction scores was 10.7 mm (95% CI, 5.5-15.8 mm). CONCLUSION: The MCSD in patient satisfaction scores measured with a 100-mm VAS was approximately 7-11 mm. Future studies evaluating differences in patient satisfaction should be designed to detect this difference.  相似文献   

11.
Epirubicin is known to be metabolized in the liver. Therefore, drugs such as cimetidine, which inhibit the cytochrome P-450 enzyme system or reduce liver blood flow, may reduce the plasma clearance of epirubicin. In a small study, epirubicin 100 mg/m2 every 3 weeks was administered intravenously to eight patients, who also received oral cimetidine (400 mg b.d. for 7 days starting 5 days before chemotherapy) with either the first or second cycles. Epirubicin pharmacokinetics and liver blood flow (idocyanine green clearance) were assessed at each course. The areas under the plasma concentration time curves (AUCs) were used to compare the systemic exposure to epirubicin and its metabolites with each course. The estimated median percentage increase (95% confidence interval CI) in the AUC with cimetidine were: epirubicin 50% (95% CI -18 to 193, epirubicinol 41% (95% CI 1 to 92). Despite the small numbers studied, the increase in the active metabolite epirubicinol was significant (P < 0.05). These changes in exposure were not explained by reduced cytochrome P-450 activity as the 7-deoxy-doxorubicinol aglycone AUC was not reduced (357% increase: 95% CI 17 to 719) or by a decrease in liver blood flow (17% increase: 95% CI -39 to 104). Cimetidine is likely to be coprescribed or self-administered with epirubicin and therefore clinicians should be aware of this potential interaction.  相似文献   

12.
PURPOSE: To investigate the effect of organ function on total and free etoposide pharmacokinetics and hematologic toxicity. PATIENTS AND METHODS: Seventy-two patients who received single-agent intravenous (i.v.) etoposide over 5 or 8 days (total dose, 500 mg/m2) were studied. Pharmacokinetic parameters were derived after analysis of total plasma etoposide by high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection, and etoposide protein binding by ultrafiltration of an etoposide-spiked, pretreatment serum sample, followed by HPLC analysis. Free etoposide area under the concentration-time curve (AUC) was derived from the total AUC and protein binding. RESULTS: Patients with renal impairment (serum creatinine level > 130 mumol/L) had a lower plasma etoposide clearance (13.6 v 18.5 mL/min/m2; P = .016), resulting in an increased total-drug and free-drug AUC (total etoposide AUC 615 v 452 micrograms/mL.hr; P = .016; free etoposide AUC 26.0 v 17.6 micrograms/mL.hr; P = .026) and increased hematologic toxicity (nadir neutrophil count 0.3 v 1.9 x 10(9)/L; P = .005). Patients with albumin levels less than 35 g/L had no change in total etoposide kinetics but had an increase in unbound etoposide (5.2% v 4.1%; P = .01), resulting in an increase in free etoposide AUC (27.5 v 16.5 micrograms/mL.hr; P = .003) and more profound toxicity (nadir neutrophil count 0.6 v 1.9 x 10(9)/L; P = .004). In patients with normal albumin and creatinine, increased toxicity in those older than 65 years was associated with a reduced drug clearance, and in those with increased liver enzymes by a trend toward an increase in free etoposide AUC. CONCLUSION: Increased hematologic toxicity after etoposide in patients with abnormal organ function is mediated by an increase in free etoposide AUC. A reduction in dose is clearly indicated in such patients.  相似文献   

13.
Since the early 1970s, three generations of combination chemotherapy for intermediate-grade non-Hodgkin's lymphomas (NHL) have been developed. One of the third-generation regimens is MACOP-B (methotrexate, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin). The VACOP-B regimen is a modification of MACOP-B in which methotrexate is omitted and etoposide is added. This study assesses treatment outcome using the MACOP-B and VACOP-B combination chemotherapy in a population of young patients with intermediate-grade NHL treated in a single tertiary hematological center. The files of 45 patients aged 18-55 who were diagnosed as having intermediate-grade NHL (working formulation types F-H) and treated between January 1986 and March 1994 were reviewed. Treatment response, overall survival, disease-free survival and treatment toxicity were determined. The predictive value of the age-adjusted international prognostic index was also assessed. Median follow-up was 80 months in the MACOP-B group and 29 months in the VACOP-B group. The complete response rate was 71% (95% confidence interval CI: 58-84), 4-year overall survival was 74 +/- 7% and 4-year disease-free survival was 79 +/- 8%. No toxicity-related deaths were observed. The main adverse effects were WHO grade 3 or 4 neutropenia (51%), anemia (24%) and mucositis (20%). Only the CR rate was correlated with the Age-Adjusted International Prognostic Index. Mean relative dose intensity was high (95.7%, 95%) CI: 91.7-99.7) and had no correlation with treatment outcome. The MACOP-B and VACOP-B combination chemotherapy regimens were found to be effective and minimally toxic for young patients up to 55 years old with intermediate-grade NHL.  相似文献   

14.
This study was designed to determine the bioavailability of etoposide capsules administered orally at doses of 50 and 75 mg. Patients with inoperable or relapsed lung cancer, who had an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2 and adequate organ function, were eligible. A group of 17 patients were evaluable, all of whom were 75 years old or less, with an ECOG performance status of 0 or 1. The bioavailability of oral etoposide was determined by measuring the area under the etoposide plasma concentration versus time curve (AUC) on days 1, 10 and 21 during a once-daily regimen of oral administration for 21 consecutive days and comparing the value with the AUC achieved following intravenous administration 1 or 2 weeks after the last oral dose. The bioavailability of 50, 75 and 100 mg oral etoposide was determined in six, nine and two patients, respectively. The mean etoposide bioavailabilities (+/- SD) of the 50-mg and 75-mg doses were 47 +/- 11% and 59 +/- 18%, respectively, and of the 100-mg dose in two patients were 51% and 33%, respectively. There was no statistically significant difference in bioavailability between the 50-mg and 75-mg doses. The bioavailability of low-dose oral etoposide was the same as that reported in previous higher dose oral etoposide bioavailability studies and that shown on the package insert supplied by the manufacturer. Improved bioavailability of low-dose oral etoposide was therefore not observed in a population of Japanese patients.  相似文献   

15.
PURPOSE: High cumulative epipodophyllotoxin dosages are reported to be associated with an elevated risk for secondary acute myeloid leukemia (s-AML). This study examined the risk of s-AML following cumulative etoposide doses greater than 2 g/m2 in patients with metastatic germ cell tumors (GCT). PATIENTS AND METHODS: The incidence of s-AML was retrospectively assessed in patients treated within clinical trials between January 1986 and February 1996 at four university centers. All patients received high-dose chemotherapy (HDCT) plus autologous stem-cell support for metastatic GCT, including high cumulative etoposide doses (> 2 g/m2). Minimum patient follow-up was 12 months. Standardized morbidity ratio (SMR) was calculated to estimate the risk associated with high cumulative etoposide doses, as compared with the general population. RESULTS: A total of 302 patients with a median age of 29 years (range, 15 to 55) received a median cumulative etoposide dose of 5 g/m2 (range, 2.4 to 14 g/m2). Four cases of s-AML were observed, which resulted in a cumulative incidence of 1.3% (95% confidence interval [CI], 0.38% to 3.59%) at 52 months of median follow-up (range, 12 to 198). Two cases of secondary myelodysplasia (s-MDS) developed in patients with primary mediastinal GCT. Based on the observed four cases of AML, which are most likely etoposide-related, the risk for developing s-AML (SMR, 160 [95% CI, 43.7 to 411.2]) is significantly increased in comparison to the age-matched general population. CONCLUSION: Due to the low incidence of AML in the general population, the significantly elevated risk for developing s-AML affects only 1.3% of all patients who receive etoposide doses greater than 2 g/m2. HDCT, including etoposide doses greater than 2 g/m2, is associated with an acceptably low incidence of s-AML in patients with advanced GCT.  相似文献   

16.
8-Carbamoyl-3-methylimidazo(5,1-d)-1,2,3,5-tetrazin-4(3H)-one (temozolomide) is a new imidazole tetrazinone compound with promising preclinical and clinical activity in nitrosourea-sensitive and -resistant models and manageable toxicity in Phase I and II clinical trials. In this study, we investigated the antiproliferative activity of temozolomide against a large variety of human tumors taken directly from patients in an in vitro soft agar tumor cloning system. Temozolomide was studied using a continuous exposure at final concentrations from 0.1 to 10.0 microM against a total of 222 tumor specimens, of which 101 (45%) were evaluable. A decrease in tumor colony formation was considered significant if survival of colonies treated with temozolomide was 相似文献   

17.
The pharmacokinetics of the immunosuppressant mycophenolate mofetil have been investigated in healthy volunteers and mainly in recipients of renal allografts. Following oral administration, mycophenolate mofetil was rapidly and completely absorbed, and underwent extensive presystemic de-esterification. Systemic plasma clearance of intravenous mycophenolate mofetil was around 10 L/min in healthy individuals, and plasma mycophenolate mofetil concentrations fell below the quantitation limit (0.4 mg/L) within 10 minutes of the cessation of infusion. Similar plasma mycophenolate mofetil concentrations were seen after intravenous administration in patients with severe renal or hepatic impairment, implying that the de-esterification process had not been substantially affected. Mycophenolic acid, the active immunosuppressant species, is glucuronidated to a stable phenolic glucuronide (MPAG) which is not pharmacologically active. Over 90% of the administered dose is eventually excreted in the urine, mostly as MPAG. The magnitude of the MPAG renal clearance indicates that active tubular secretion of MPAG must occur. At clinically relevant concentrations, mycophenolic acid and MPAG are about 97% and 82% bound to albumin, respectively. MPAG at high (but clinically realisable) concentrations reduced the plasma binding of mycophenolic acid. The mean maximum plasma mycophenolic acid concentration (Cmax) after a mycophenolate mofetil 1 g dose in healthy individuals was around 25 mg/L, occurred at 0.8 hours postdose, decayed with a mean apparent half-life (t1/2) of around 16 hours, and generated a mean total area under the plasma concentration-time curve (AUC infinity) of around 64 mg.h/L. Intra- and interindividual coefficients of variation for the AUC infinity of the drug were estimated to be 25% and 10%, respectively. Intravenous and oral administration of mycophenolate mofetil showed statistically equivalent MPA AUC infinity values in healthy individuals. Compared with mycophenolic acid, MPAG showed a roughly similar Cmax about 1 hour after mycophenolic acid Cmax, with a similar t1/2 and an AUC infinity about 5-fold larger than that for mycophenolic acid. Secondary mycophenolic acid peaks represent a significant enterohepatic cycling process. Since MPAG was the sole material excreted in bile, entrohepatic cycling must involve colonic bacterial deconjugation of MPAG. An oral cholestyramine interaction study showed that the mean contribution of entrohepatic cycling to the AUC infinity of mycophenolic acid was around 40% with a range of 10 to 60%. The pharmacokinetics of patients with renal transplants (after 3 months or more) compared with those of healthy individuals were similar after oral mycophenolate mofetil. Immediately post-transplant, the mean Cmax and AUC infinity of mycophenolic acid were 30 to 50% of those in the 3-month post-transplant patients. These parameters rose slowly over the 3-month interval. Slow metabolic changes, rather than poor absorption, seem responsible for this nonstationarity, since intravenous and oral administration of mycophenolate mofetil in the immediate post-transplant period generated comparable MPA AUC infinity values. Renal impairment had no major effect on the pharmacokinetic of mycophenolic acid after single doses of mycophenolate mofetil, but there was a progressive decrease in MPAG clearance as glomerular filtration rate (GFR) declined. Compared to individuals with a normal GFR, patients with severe renal impairment (GFR 1.5 L/h/1.73m2) showed 3-to 6-fold higher MPAG AUC values. In rental transplant recipients during acute renal impairment in the early post-transplant period, the plasma MPA concentrations were comparable to those in patients without renal failure, whereas plasma MPAG concentrations were 2- to 3-fold higher. Haemodialysis had no major effect on plasma mycophenolic acid or MPAG. Dosage adjustments appear to not be necessary either in renal impairment or during dialysis. (ABSTRACT TRUN  相似文献   

18.
There have been few reports about the frequency of multiple sclerosis (MS) in Spain. We undertook a prevalence study in the province of Teruel, which is served by two hospitals as referral centres for a population of 143,680. We found a total of 46 patients who fulfilled Poser's criteria for clinically definite or probable MS with a prevalence rate of 32/100,000 [95% confidence interval (CI): 22.8-41.3]. The prevalence rates for males and females were 23.5 (95% CI: 12.3-34.7) and 40.6 (95% CI: 25.8-55.4) respectively. We found an incidence rate of 2.2/year per 100,000 in the last 5 years. The sex ratio (females/males) was 1.7. The mean age on prevalence day was 40.6 years (range: 15-76). The clinical course was relapsing-remitting in 82% of patients, progressive in 9% and secondary progressive in the other 9%. The mean EDSS score was 3.73 (range: 1-8.5). Our results confirm the hypothesis that Spain is an area at high risk for MS.  相似文献   

19.
BACKGROUND: Etoposide is a highly schedule-dependent drug. We investigated combination chemotherapy of oral etoposide and intravenous cisplatin for small cell lung cancer (SCLC). METHODS: Fifty-seven patients with SCLC with extensive disease (ED) or limited disease (LD) with pleural effusion registered in the 21 institutions of the Japan Clinical Oncology Group were treated with oral etoposide 40 mg/m2/d for 21 days and cisplatin 80 mg/m2 on day 1 of every 28-period day. The entry period was between February 1992 and August 1995. The actual percentages of patients treated with etoposide were 93.6, 89.5, 92.3 and 96.9% in the first, second, third and fourth cycles, respectively. RESULTS: Nine patients (15.8%) achieved a complete response resulting in an overall response rate of 82.5% (95% confidence interval, 70.1-91.3%). Leukopenia and thrombocytopenia of grade 3 or 4 were observed in 36 (49.1%) and 8 (14.0%) patients, respectively. Anemia of grade 3 or 4 occurred in 28 (49.1%) patients. Nausea, vomiting, anorexia and alopecia were common adverse events. One patient died of hemoptysis due to grade 4 thrombocytopenia. The mean survival time was 47.0 weeks. CONCLUSIONS: This dose and schedule of administration of etoposide in combination with cisplatin are considered to be clinically active. However, prolonged gastrointestinal toxicity of oral etoposide was a problem in comparison with the standard etoposide platinum regimen given by intravenous administration.  相似文献   

20.
OBJECTIVE: To determine the accuracy of CT of the chest in diagnosing the presence of cardiac injury in stable patients with penetrating chest injuries. METHODS: A retrospective chart review of a convenience sample of stable patients with penetrating thoracic wounds evaluated for hemopericardium using chest CT at an urban level I trauma center. RESULTS: 60 stable patients with penetrating wounds in proximity to the heart underwent CT. Three patients had radiographic evidence of pericardial fluid, and 1 had an equivocal study. These 4 patients underwent subxiphoid pericardial window exploration: 2 had only clear fluid present, the other 2 had hemopericardium. The latter patients had a total of 3 cardiac and 1 diaphragmatic injuries, which were repaired at subsequent sternotomy. None of the 56 patients who had negative CTs had further clinical evidence of cardiac injury. The sensitivity, specificity, and accuracy of CT in this setting for hemopericardium are 100% (95% CI 18-100%), 96.6% (95% CI 88-100%), and 96.7% (95% CI 89-100%), respectively. CONCLUSION: Chest CT may be a useful test for diagnosing the presence of hemopericardium in the setting of penetrating thoracic injury. With the caveat that the patient must be removed from a closely monitored environment, the authors the use of CT in stable patients with penetrating chest wounds whenever echocardiography is unavailable.  相似文献   

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