Biomedical subjects

J F Bishop

Publications and source records attributed to J F Bishop.

At least 37 records · Page 2Linked to original sources

PubMed1998

A phase II trial of carboplatin and etoposide for relapsed or metastatic carcinoma of the cervix.

This study reports the results of a phase II trial of carboplatin 100 mg/m2 combined with etoposide 120 mg/m2 each given for 3 consecutive days every 28 days in women with recurrent or metastatic carcinoma of the cervix. Seventeen eligible patients were treated between August, 1990 and May, 1993. In the 16 evaluable patients, there were 2 complete responses, and no partial responses with an overall objective response rate of 12.5% (95% confidence interval 1.6%-38%). The main toxicities of this regimen related to myelosuppression and emesis. The combination of carboplatin and etoposide did not achieve either a better response rate or a substantially improved toxicity profile than is seen with single agent cisplatin.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1998

Approaches to induction therapy with adult acute myeloid leukaemia.

Induction therapy of acute myeloid leukaemia (AML) with standard-dose chemotherapy will result in approximately 64% of patients achieving a complete remission (CR). New drugs which are active in induction therapy in randomised clinical trials are etoposide, idarubicin and high dose cytarabine. Intensification of induction treatment with etoposide or high-dose cytarabine does not appear to alter the CR rate but prolongs remission and has some impact on survival. High-dose cytarabine in induction combinations increase relapse-free survival compared to standard approaches. These induction results appear to parallel results obtained with post-remission therapies intensified with high-dose cytarabine. These studies provide clinical evidence that intensified induction with cytarabine in AML influences subsequent outcome but is more toxic, gives more profound myelosuppression post-remission and has benefit confined to younger patients.

Acute Disease↗

PubMed1998

Low-dose versus standard-dose lenograstim prophylaxis after chemotherapy: a randomized, crossover comparison.

PURPOSE: Granulocyte colony-stimulating factor (G-CSF) administered prophylactically after chemotherapy reduces the duration and severity of neutropenia. This randomized crossover study was designed to assess whether a lower dose of G-CSF is as effective as a standard dose of 5 microg/kg daily. PATIENTS AND METHODS: Patients who received standard-dose chemotherapy regimens expected to cause neutropenia received G-CSF (lenograstim) that started the day after chemotherapy for 14 days or until the absolute neutrophil count (ANC) recovered to greater than 10 x 10(9)/L. The lenograstim dose was randomly allocated to be 2 or 5 microg/kg daily in the first cycle of chemotherapy and crossed over to the alternate dose for the second cycle. The study was designed to accrue 40 assessable patients to provide a power of 80% to detect a difference in duration of neutropenia of 1 day. Fifty-two patients were randomized to treatment and 43 patients completed two cycles of identical chemotherapy. RESULTS: There was little neutropenia irrespective of the dose used. Twenty-three patients (53%) had no grade III or IV neutropenia and 30 patients (70%) had no grade IV neutropenia. Crossover trial methodology was used to assess the difference in outcome caused by the lower dose compared with the standard dose (estimated treatment effect). There was no significant difference in the measures of neutropenia, hospitalization, or other clinical outcomes. The 95% confidence interval (one-sided) for the additional duration of neutropenia caused by the lower dose of lenograstim was 0.43 days or less for grade III or IV neutropenia and 0.34 days or less for grade IV neutropenia. CONCLUSION: Lenograstim 2 microg/kg provides similar protection to 5 microg/kg against neutropenia that complicates standard-dose chemotherapy. The use of a lower dose has important implications for the cost-effectiveness of prophylactic G-CSF therapy.

Adjuvants, Immunologic↗

PubMed1998

Intensified induction chemotherapy with high dose cytarabine and etoposide for acute myeloid leukemia: a review and updated results of the Australian Leukemia Study Group.

Induction therapy of acute myeloid leukemia (AML) with standard dose chemotherapy will result in approximately 55-75% of patients achieving a complete remission (CR). Intensification of induction treatment with etoposide and high dose cytarabine does not alter the CR rate but appears to significantly improve the subsequent outcome. Updated results of the comparison of high dose cytarabine with daunorubicin and etoposide in induction (HIDAC-3-7) versus a standard dose combination (7-3-7) demonstrated a highly significant increase in relapse free survival, (RFS) on the high dose arm (p = 0.007) with RFS of 48% at 5 years with HIDAC-3-7 and 25% on 7-3-7. The high dose arm had a more modest survival advantage at 5 years of 33% compared with 25% on standard treatment, possibly because of a higher initial death rate with HIDAC-3-7. The improvement seen in patients with CR after high dose induction appear to parallel results obtained with post-remission therapies intensified with high dose cytarabine. These studies provide clinical evidence that a dose-response effect is present for cytarabine in AML. Intensified treatment is more toxic, gives more profound myelosuppression post-remission and has been shown to benefit younger patients only. Issues of patient selection and the optimal placement of intensification in the treatment sequence require further study. In the future, it is likely that remission duration may be a useful clinical tool to study the influence of new induction therapies on residual resistant leukemia.

Acute Disease↗

PubMed1998

Phase I trial of cremophor EL with bolus doxorubicin.

Cremophor EL (cremophor), a component of the paclitaxel formulation, can potentially reverse P-glycoprotein-associated multidrug resistance. A Phase I trial of cremophor as a 6-h infusion every 3 weeks was performed with bolus doxorubicin (50 mg/m2). The cremophor dose was escalated from 1 to 60 ml/m2. A standard paclitaxel premedication was given before cremophor. Using a bioassay, potentially active cremophor levels (> or = 1 microl/ml) were measured in plasma from patients receiving cremophor doses of 30, 45, and 60 ml/m2. A cross-over design was used to assess the influence of cremophor 30 ml/m2 on the pharmacokinetics of doxorubicin and doxorubicinol. The plasma area under the concentration versus time curve (AUC) of doxorubicin increased from 1448 +/- 350 to 1786 +/- 264 ng/ml x h (P = 0.02) in the presence of cremophor, whereas the AUC of doxorubicinol increased from 252 +/- 104 to 486 +/- 107 ng/ml x h (P = 0.02). This pharmacokinetic interaction was associated with significantly increased neutropenia. With reduction of the doxorubicin dose to 35 mg/m2, the cremophor dose was increased to 60 ml/m2. Dose-limiting toxicities occurred in two of six patients after 45 ml/m2 and two of four patients after 60 ml/m2, which included febrile neutropenia and grade III cremophor-related toxicities of rash, pruritus, headache, and hypotension. All patients who received 45 ml/m2 cremophor reached plasma levels > or = 1.5 microl/ml, but at 60 ml/m2, only two of four reached this level, and the calculated plasma clearance of cremophor was significantly faster at this dose. One patient with hepatoma resistant to epirubicin achieved a near-complete response. Cremophor 45 ml/m2 over 6 h with 35 mg/m2 doxorubicin is recommended for further studies. The pharmacokinetic interaction between cremophor and doxorubicin is quantitatively similar to that described in trials of paclitaxel with doxorubicin and suggests that the cremophor in the paclitaxel formulation is responsible.

Adult↗

PubMed1997

Localization of putative calcium-responsive regions in the rat BDNF gene.

Brain-derived neurotrophic factor (BDNF) has potent trophic and protective actions on CNS neurons, including mesencephalic dopaminergic neurons, ventral forebrain cholinergic neurons and spinal motor neurons. To evaluate the effects of calcium and other second messengers on BDNF gene transcription, C6 glioma cells were treated for 4 h with the calcium ionophore A23187, forskolin + isobutyl-methyl-xanthine (IBMX), or the phorbol ester, 12-O-tetradecanoyl-phorbol-13-acetate. Semi-quantitative RT-PCR analysis revealed that A23187 treatment increased BDNF transcripts containing the protein coding exon by 4.4-6.4-fold. Alternate BDNF transcripts were elevated to varying degrees after treatment with this ionophore and a subset of these transcripts was elevated following forskolin + IBMX treatment. When co-incubated with the RNA polymerase inhibitor, actinomycin D, A23187-induced increases were reduced or abolished, suggesting that calcium-mediated regulation of BDNF mRNA expression occurs at transcriptional as well as post-transcriptional levels. Transient transfection experiments employing reporter constructs containing serial 5' deletions of alternate BDNF promoters suggested that A23187-induced elevations in BDNF exon 1b, 1d and 1e containing transcripts are mediated by putative calcium-responsive regions flanking all three of these exons.

Animals↗

PubMed1997

Australian multicentre phase II trial of paclitaxel in women with metastatic breast cancer and prior chemotherapy.

OBJECTIVE: To determine the efficacy and safety of paclitaxel given as a three-hour infusion in patients with metastatic breast cancer which had progressed despite hormonal therapy and/or chemotherapy. DESIGN AND SETTING: Multicentre phase it trial undertaken in five major centres or hospitals in Sydney, Melbourne and Adelaide. PATIENTS AND METHODS: 50 patients with clinically or radiologically measurable or evaluable metastatic breast cancer recruited between March and July 1993. All had received prior chemotherapy, with subsequent disease progression. INTERVENTION: Paclitaxel (Anzatax, Faulding) was given at a dose of 175 mg/m2 intravenously over three hours every three weeks for up to nine courses. MAIN OUTCOME MEASURES: Response rate (partial or complete); duration of progression-free survival; duration of survival; and adverse reactions. RESULTS: Patients had a median age of 51 years; 62% had received at least two prior drug regimens for metastatic breast cancer and 48% had anthracycline-resistant tumours. A median of six paclitaxel courses was given per patient. Overall response rate was 18% (95% confidence interval [95% CI], 9%-31%), with complete responses in four patients (8%). In patients with anthracycline-resistant tumours, response rate was 25% (95% CI, 10%-47%). Response was not influenced by extent of prior treatment. Estimated median progression-free survival was 4.1 months (95% CI, 3.2-6.0 months) and estimated median survival was 6.3 months (95% CI, 6.2-10.3 months). Treatment was well tolerated, with neutropenia the major toxic effect. CONCLUSIONS: Paclitaxel (three-hour infusion) has significant activity in heavily pretreated patients with metastatic breast cancer, including anthracycline-resistant tumours.

Adult↗

PubMed1997

Radioenhancement by cisplatin with accelerated fractionated radiotherapy in a human tumour xenograft.

The aim of the present study was to investigate whether cisplatin would enhance the radioresponse of a human tumour xenograft when given in different schedules combined with accelerated fractionated radiation therapy. A human squamous carcinoma of the hypopharynx, FaDu, was grown in the thigh of athymic nude mice. Tumours were exposed to twice-daily 2-Gy fractions, applied 6 h apart over 2 weeks, 5 days a week, alone or combined with cisplatin given at maximally tolerated doses in three different schedules: (1) i.p. as a single bolus (SB) or (2) i.p. as a daily bolus at 30 min before the first daily radiation fraction or (3) s.c. as a continuous infusion through a mini-osmotic pump over 13 days, commencing 24 h prior to the first daily radiation fraction. The end point for the study was tumour growth delay (TGD), calculated as the difference between the delay in regrowth to 200% of the initial tumour size in treated versus control mice. SB cisplatin plus radiation showed only an additive effect on TGD, whereas daily-bolus and continuous-infusion cisplatin demonstrated a greater than additive effect when combined with accelerated fractionated radiation in this human tumour model. Cisplatin appears to be especially beneficial as a radiation enhancer when given throughout the course of radiation.

Animals↗

PubMed1997

Phase I dose intensification study of 2-weekly epirubicin with GM-CSF in advanced cancer.

This study investigated dose intensification of epirubicin administered as a 2-weekly regimen with granulocyte-macrophage colony-stimulating factor (GM-CSF) support. The aim was to define the maximally tolerated dose of epirubicin and to assess the efficacy of GM-CSF to ameliorate its toxicity. Patients with anthracycline-responsive advanced malignancies were eligible. Six dose levels, commencing at 90 mg/m2, of epirubicin administered every 2 weeks for four courses were planned with GM-CSF 10 micrograms/kg/day administered for 10 days from the second day of each course. Six patients were to be entered at each dose level, and escalation to the next level was based upon toxicity criteria. Twelve patients were entered, six at dose level 1 (90 mg/m2) and six at dose level 2 (120 mg/m2). Prospectively defined haematological dose-limiting toxicities were noted in one patient at dose level 1 and in five patients at dose level 2. Further dose escalation was not attempted. Significant nonhaematological toxicities included febrile neutropenia in two and four patients at dose levels 1 and 2, respectively. This study has demonstrated that epirubicin can be safely administered at 2 week intervals with GM-CSF at a dose of 90 mg/m2, equivalent to the previously reported maximum tolerated dose intensity of 45 mg/m2/week. Neutropenia was dose-limiting despite the use of GM-CSF.

Adjuvants, Immunologic↗

PubMed1997

A phase II trial of cisplatin and interferon alpha 2b in patients with advanced bladder cancer.

Twenty-two patients with advanced transitional cell bladder cancer were treated in a phase II trial exploring the possible synergy of cisplatin and interferon alpha 2b. Of the 20 evaluable patients, 7 (35%) had a partial response to the treatment, and only 6 patients were able to complete the full planned six cycles of treatment. Response rates, duration of responses, and overall survival of our patients are not superior to those expected by cisplatin alone.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1997

Phase I trial of docetaxel and cisplatin in previously untreated patients with advanced non-small-cell lung cancer.

PURPOSE: To determine the maximum-tolerated doses (MTDs), principal toxicities, and pharmacokinetics of the combination of docetaxel and cisplatin administered every 3 weeks to patients with advanced non-small-cell lung cancer (NSCLC) who have not received prior chemotherapy and to recommend a dose for phase II studies. PATIENTS AND METHODS: Patients with advanced NSCLC and performance status 0 to 2 who had not received prior chemotherapy received docetaxel over 1 hour followed by cisplatin over 1 hour with hydration. Dose levels studied were (docetaxel/cisplatin) 50/75, 75/75, 75/100, and 100/75 mg/m2 repeated every 3 weeks. Colony-stimulating factor (CSF) support was not used. Pharmacokinetics of docetaxel and cisplatin were studied in the first cycle of therapy. Most patients (79%) had metastatic disease or intrathoracic recurrence after prior radiation and/or surgery. RESULTS: Of 24 patients entered, all were assessable for toxicity and 18 for response. The MTD schedules were docetaxel 75 mg/m2 with cisplatin 100 mg/m2 (dose-limiting toxicities [DLTs] in five of six patients), and docetaxel 100 mg/m2 with cisplatin 75 mg/m2 (DLTs in two of two patients, including one fatal toxicity). Limiting toxicities were febrile neutropenia and nonhematologic, principally diarrhea and renal. Two patients had neutropenic enterocolitis. Pharmacokinetics of both drugs were consistent with results from single-agent studies, which suggests no major pharmacokinetic interaction. Neutropenia was related to docetaxel area under the plasma concentration-versus-time curve (AUC). An alternative schedule was investigated, with cisplatin being administered over 3 hours commencing 3 hours after docetaxel, but toxicity did not appear to be less. Independently reviewed responses occurred in eight of 18 patients (44%; 95% confidence interval, 22% to 69%), most following 75 mg/m2 of both drugs. CONCLUSION: Docetaxel 75 mg/m2 over 1 hour followed by cisplatin 75 mg/m2 over 1 hour is recommended for phase II studies. The responses seen in this phase I study suggest a high degree of activity of this combination in previously untreated advanced NSCLC.

Adult↗

PubMed1997

The treatment of adult acute myeloid leukemia.

Induction therapy of acute myeloid leukemia (AML) with standard-dose chemotherapy will result in 52% to 72% of patients achieving a complete remission (CR) on bone marrow morphology. Newer agents that appear to improve the outcome of induction therapy are etoposide, idarubicin, and high-dose cytarabine. New studies are now required to define new induction combinations and the place of these and other promising new drugs in the treatment. Standard attenuated postremission therapy is required after standard induction to maintain remission. However, new intensified postremission therapies have significantly improved outcome in de novo AML. This development has required re-examination of the value of intensive treatment. There is now clear clinical evidence that a dose-response effect is present for cytarabine in AML. The optimal placement of intensified treatment and marrow transplantation requires further study. In the future, it is likely that new treatment strategies will be defined by identifying new prognostic subgroups. To identify new successful induction treatments in AML, more precise measures of CR are required including an attempt to define cytogenetic CR and molecular CR wherever it can be applied. A theoretical model of blast cell kill would suggest that remission duration may be a useful clinical end point to study the influence of new induction therapies on residual resistant leukemia.

Acute Disease↗

PubMed1997

Paclitaxel as first-line treatment for metastatic breast cancer. The Taxol Investigational Trials Group, Australia and New Zealand.

When administered as a single agent in pretreated patients with advanced breast cancer, paclitaxel (Taxol) exhibits remarkable antitumor activity. This trial was undertaken to compare paclitaxel with standard chemotherapy as front-line therapy for this disease. Patients with measurable or evaluable metastatic breast cancer, no prior chemotherapy for metastatic disease, and an Eastern Cooperative Oncology Group performance status of 0 to 2 were randomized to receive paclitaxel 200 mg/m2 intravenously over 3 hours for eight cycles (6 months) or standard treatment with oral cyclophosphamide (Cytoxan) 100 mg/m2/d days 1 through 14, intravenous methotrexate 40 mg/ m2 days 1 and 8, intravenous 5-fluorouracil 600 mg/m2 days 1 and 8, and oral prednisolone 40 mg/m2/d (CMFP) days 1 through 14 for six cycles (6 months). Patients whose disease progressed or relapsed were recommended to receive second-line epirubicin. Accrual has been completed with 208 patients randomized, but a preplanned interim analysis of the first 100 patients is reported here. Analysis of quality of life, assessed by a linear analogue scale and overall quality of life indices, is ongoing. Objective response occurred in 31% (confidence interval, 19% to 45%) with paclitaxel and 35% (confidence interval, 22% to 51%) with CMFP with stable disease in an additional 33% and 29%, respectively. Median time to progression was 5.5 months for paclitaxel-treated patients and 6.4 months for those given CMFP, with median survival durations of 17.3 and 11.3 months, respectively. Grades 3 and 4 neutropenia occurred in 64% of patients treated with paclitaxel and in 63% treated with CMFP. However, febrile neutropenia was the primary reason for hospitalization in 1% of paclitaxel courses, compared with 8% of CMFP courses. Nine percent of the patients had major infections with CMFP, but none were seen with paclitaxel. Moderate or severe mucositis occurred in 13% of paclitaxel-treated and 27% of CMFP-treated patients. Alopecia and peripheral neuropathy were more common with paclitaxel. Quality of life assessments in the first 100 patients suggest better overall results on paclitaxel treatment as compared with CMFP. Preliminary analyses suggest that single-agent paclitaxel is well tolerated and provides comparable control of metastatic cancer to CMFP combination therapy when used as front-line treatment.

Antineoplastic Agents↗

PubMed1997

A randomized study of paclitaxel versus cyclophosphamide/methotrexate/5-fluorouracil/prednisone in previously untreated patients with advanced breast cancer: preliminary results. Taxol Investigational Trials Group, Australia/New Zealand.

When administered as a single agent to previously treated patients with advanced breast cancer, paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) has good activity. This trial was undertaken to compare paclitaxel with standard chemotherapy as front-line treatment for this disease. Patients with measurable or evaluable metastatic breast cancer, no prior chemotherapy for metastatic disease, and Eastern Cooperative Oncology Group performance status of 0 to 2 were randomized to receive either paclitaxel 200 mg/m2 intravenously over 3 hours for eight cycles over 24 weeks or standard treatment with oral cyclophosphamide 100 mg/m2/d days 1 to 14, intravenous methotrexate 40 mg/m2 days 1 and 8, intravenous 5-fluorouracil 600 mg/m2 days 1 and 8, and oral prednisone 40 mg/m2 daily days 1 to 14 (CMFP) for six cycles over 24 weeks. Patients whose disease progressed or relapsed were recommended for second-line therapy with epirubicin. Accrual has been completed with 209 patients randomized, and an interim analysis of the first 100 patients is reported here. Analysis of quality of life, assessed by the linear analogue scale and overall quality of life indices, is ongoing. Objective response occurred in 31% (confidence interval, 19% to 45%) with paclitaxel and 35% (confidence interval, 22% to 51%) with CMFP, with stable disease in an additional 33% and 29%, respectively. Median time to progression was 5.5 months with paclitaxel and 6.4 months with CMFP, with a median survival of 17.3 months for patients treated with paclitaxel and 11.3 months for those given CMFP. Grades 3 and 4 neutropenia occurred in 64% of patients with paclitaxel and 63% with CMFP. However, febrile neutropenia was the primary reason for hospitalization in 1% of paclitaxel courses, compared with 8% with CMFP. Major infections (World Health Organization grade 4) were seen in 7% of patients treated with CMFP, but in none of those given paclitaxel. Moderate or severe mucositis occurred in 13% of paclitaxel and 27% of CMFP patients. Alopecia and peripheral neuropathy were more common with paclitaxel. Quality of life assessments in the first 100 patients suggest better overall results for those treated with paclitaxel compared with CMFP. Preliminary analyses suggest that single-agent paclitaxel is well tolerated and provides control of metastatic cancer comparable to that of CMFP combination therapy when used as front-line therapy in an outpatient setting.

Antineoplastic Agents, Phytogenic↗

PubMed1997

The pharmacoeconomics of cancer therapies.

Paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) is a taxane with a wide spectrum of antitumor activity. Combination chemotherapy with paclitaxel plus cisplatin has been shown to be more active than older drug combinations in the treatment of ovarian cancer and non-small cell lung cancer. Paclitaxel also appears to be as active as other therapies for the first-line treatment of breast cancer, and an established salvage treatment after platinum therapy for ovarian cancer and after anthracycline therapy for breast cancer. Ongoing clinical trials are evaluating the role of paclitaxel in the adjuvant treatment of breast cancer and in early stage lung cancer. Cost analysis of combination paclitaxel/cisplatin treatment for ovarian cancer indicated drug costs represented a low proportion of inpatient costs, making it cost effective per life-year gained in both the inpatient and outpatient settings. In extensive cost analyses of lung cancer therapies in Canada, best supportive care for stage IV lung cancer was shown to cost more than Can$28,000. In this setting, with an expected increase in survival, the cost of treating stage IV lung cancer with paclitaxel appears to be cost effective. Furthermore, in a large randomized study of paclitaxel versus cyclophosphamide/methotrexate/5-fluorouracil/prednisone in breast cancer, preliminary results suggested that paclitaxel may be associated with equivalent cancer control, quality of life, and less side effects. Thus, future research will consider the cost-benefit of improved quality of life with paclitaxel therapy and evaluate the comparative cost-benefit when taxanes are used to treat earlier-stage disease.

Antineoplastic Agents, Phytogenic↗

PubMed1996

Cremophor pharmacokinetics in patients receiving 3-, 6-, and 24-hour infusions of paclitaxel.

BACKGROUND: Paclitaxel (Taxol) is a new drug with efficacy against a variety of malignant tumors. The clinical formulation of paclitaxel contains 50% Cremophor EL, a polyethoxylated castor oil vehicle (carrier) that can reverse multidrug resistance (MDR) mediated by P-glycoprotein. Three-hour intravenous infusions of paclitaxel can yield end-of-infusion plasma Cremophor concentrations of 1 microL/mL or more, which are sufficient to reverse MDR in vitro by at least 50%. Despite extensive clinical use, the pharmacokinetics of Cremophor have not been described. PURPOSE: We studied the pharmacokinetics of Cremophor in patients with ovarian cancer who were undergoing treatment with paclitaxel to determine whether plasma Cremophor concentrations achieved during and following 3-, 6-, and 24-hour drug infusions were similar to those shown to modulate MDR in vitro. METHODS: Eleven patients with previously treated (i.e., with platinum-containing chemotherapy regimens) ovarian cancer were randomly assigned to receive one 3-hour, one 6-hour, and one 24-hour infusion of paclitaxel in varied sequences during their first three cycles of treatment with this drug. Blood samples were collected both during and following the three infusion periods, and Cremophor concentrations in these samples were measured by use of a bioassay based on the ability of Cremophor in plasma samples to reverse cellular resistance to daunorubicin in vitro. RESULTS: Ten patients were treated with paclitaxel at a dose level of 175 mg/m2, and one patient was treated at a dose level of 135 mg/m2. At the 175-mg/m2 dose level, peak plasma Cremophor concentrations of 1 microL/mL or more were achieved in eight of 10 patients during both the 3-hour and the 6-hour infusions; with the 24-hour infusion, only one patient achieved a peak plasma Cremophor concentration of 1 microL/mL or more. The eight patients who achieved plasma Cremophor concentrations of 1 microL/mL during the 3-hour infusion were above this level 30 minutes into the infusion; the total time that the plasma concentration was greater than 1 microL/mL was 8.9 +/- 5.0 hours (mean +/- standard deviation; range, 4.1-15.6 hours). For the eight patients who achieved plasma Cremophor concentrations of 1 microL/mL during the 6-hour infusion, the total time that the concentration was greater than 1 microL/mL was 10.2 +/- 9.0 hours (range, 0.3-21.9 hours). The patient who received paclitaxel at a dose of 135 mg/m2 achieved a peak plasma Cremophor concentration of 1 microL/mL or more only during the 3-hour infusion. CONCLUSIONS: Paclitaxel infusions of 3 and 6 hours can result in sustained plasma Cremophor concentrations sufficient for substantial reversal of P-glycoprotein-mediated MDR in vitro. These plasma Cremophor concentrations are not achieved during 24-hour infusions of paclitaxel.

Aged↗

PubMed1996

A randomized study of high-dose cytarabine in induction in acute myeloid leukemia.

High-dose cytarabine (ara-c) may overcome cytarabine resistance in leukemic blasts. It has been used as a successful salvage and in postremission therapy but not as initial induction treatment. Patients aged 15 to 60 years, presenting with newly diagnosed acute myeloid leukemia (AML) were randomized to receive either high-dose cytarabine, 3 g/m2 12 hourly on days 1, 3, 5, and 7 for 8 doses, daunorubicin 50 mg/m2 days 1 to 3, etoposide 75 mg/m2 days 1 to 7, (HIDAC-3-7) or standard dose cytarabine 100 mg/m2 continuous intravenous infusion for 7 days with daunorubicin and etoposide at the same dose and schedule as above (7-3-7). Patients could receive a second or third induction course if complete remission (CR) was not achieved. All patients received the same postinduction consolidation therapy (5-2-5) for 2 courses. Eligible patients had no prior chemotherapy or myelodysplastic disease. Patients have been followed for a median of 4.5 years. Of 301 patients treated, complete response (CR) was achieved in 71% with HIDAC-3-7 and 74% with 7-3-7. For patients in CR, the estimated median remission duration was 45 months with HIDAC-3-7 and 12 months with 7-3-7 (P = .0005 univariate analysis, P = .0004 multivariate analysis). The estimated percentage of patients relapse free 5 years after achieving a CR was 49% on HIDAC-3-7 and 24% on 7-3-7. Patients in CR tended to survive longer with HIDAC-3-7 but there were no overall survival differences between the two arms. HIDAC-3-7 was associated with significantly more toxicity in induction with more leukopenia, thrombocytopenia, nausea, and vomiting and eye toxicity (all P < .001) but a similar incidence of severe central nervous system and cerebellar toxicity compared to 7-3-7. The consolidation treatment was the same in both arms but caused significantly more leukopenia and thrombocytopenia in patients previously treated with HIDAC-3-7 induction (P < .0001). We conclude that a dose-effect exists for cytarabine in AML and that HIDAC-3-7 prolongs remission duration and disease-free survival and is tolerable when used as initial induction therapy in patients with de novo AML.

Acute Disease↗

PubMed1996

Up-regulation of D3 dopamine receptor mRNA by neuroleptics.

The effects of 14 days neuroleptic treatment on the expression of the D3 dopamine receptor gene was investigated in rats using a sensitive polymerase chain reaction assay. In olfactory tubercle, D3 mRNA levels increased following haloperidol (40%), pimozide (56%), and sulpiride (63%) administration, and in nucleus accumbens, levels increased after haloperidol (50%) and sulpiride (50%). D3 expression in the motor striatum did not change with any antagonist tested. Clozapine did not affect D3 expression in any brain region. These data suggest that dopamine antagonists can regulate the expression of the D3 receptor in a brain region selective manner. The findings also suggest that the motor complications of chronic antipsychotic therapy are not due to D3 receptor up-regulation in the striatum.

Animals↗