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Biomedical subjects

K Mross

Publications and source records attributed to K Mross.

At least 37 records · Page 2Linked to original sources
PubMed2001

Palliative chemotherapy in pretreated patients with advanced cancer: oral trofosfamide is effective in ovarian carcinoma.

Thirty-four patients with advanced cancer of various origins and documented disease progression were treated with continuous daily doses of 50-150 mg of oral trofosfamide (TRO). Of 31 evaluable patients, 5 responded to this treatment (1 complete remission and 4 partial remissions) and 12 patients had stable disease. Four of 9 patients with advanced ovarian cancer resistant to platinum-containing regimens and paclitaxel responded to oral TRO. The median treatment duration was 26 weeks for responders and 6 weeks for nonresponders, with cumulative doses of up to 46.000 mg TRO. Response duration was 11-47 weeks. No significant side effects were observed. Oral TRO given in the outpatient setting seems to be an attractive therapeutic option for heavily pretreated cancer patients, and it has remarkable antitumor effects in patients with ovarian cancer.

Adult↗
PubMed2001

[Clinical trials: prerequisite of evidence-based oncology: reality, perspectives and a new tool recruited--the Internet].

Scientifically sound clinical research is an undispensable prerequisite to establish innovative therapeutic principles, to support applications for marketing authorization of proprietary new drugs, to advance therapeutic results in cancer therapy, and the only route towards an evidence-based clinical oncology at the advent of the 21st century. Treatment of cancer patients based on scientific evidence derived from clinical studies outperforms compassionate individual therapeutic decisions with a lack of evidence, whenever such evidence is available or whenever a clinical trial is addressing the clinical situation that must be addressed for an individual patient. A stable trend towards improved survival of cancer patients was first observed in 1999. The advent of new technologies of drug design, the integration of pharmacology, genomics and DNA microarray chip technologies will produce a myriad of new anticancer drugs with promising potential for cancer therapy that need to be tested in the clinical setting without delay. To match that challenge, clinical oncology must streamline the laborious process of conducting clinical trials. The process of planning, multicenter coordinating, recruiting, treatment, analyzing, and reporting of clinical trial results must be further optimized. The best possible quality control of all steps of that process is a prerequisite to motivate patients to participate in clinical trials of cancer therapy - always one of the most promising treatment options for patients seeking the best possible cancer care. At the same time as the internet goes mainstream and cancer care information is ubiquitously laymanized and dispersed via cancer cybermedicine, clinical researchers may employ the internet to exchange information, facilitate conduction of clinical trials, and facilitate recruitment to clinical studies via web-based trial registries. This will be more than an incremental step forward to deliver the best possible clinical care towards the ultimate goal: to deliver evidence-based medicine en route to a cure for more cancer patients than ever.

Clinical Trials as Topic↗
PubMed2000

The pharmacokinetics of a 1-h paclitaxel infusion.

PURPOSE: To characterize the disposition of paclitaxel (PAC) after a 1-h infusion in humans and define if possible a pharmacodynamic relationship between PAC disposition and the observed toxicity. PATIENTS AND METHODS: PAC pharmacokinetics were studied in 43 courses of therapy in 30 patients (30 first course, 13 PK third course). PAC was administered at 150, 175, 200, 225 and 250 mg/m2 by a 1-h infusion to patients with advanced cancer (lung, breast, ovarian, cervix, and head and neck). PAC was quantified by high-performance liquid chromatography (HPLC). Pharmacokinetic parameters were calculated by noncompartmental and model-dependent methods. RESULTS: Increases in the area under the curve and the peak plasma concentration were not proportional to increases in the dose. However, the deviation from linearity is rather moderate. The dose-limiting toxicity was central neuropathy which was not associated with pharmacokinetic deviations. Owing to the absence of grade 3 or 4 myelotoxicity, no clear correlation between this toxicity and pharmacokinetic parameters could be established. CONCLUSION: Within the evaluated dose range of the 1-h infusion there was only a moderate nonlinear disposition of PAC in humans and therefore a dose of 225 mg/m2 is recommended as safe. The observation of central neuropathy could not be directly related to a pharmacokinetic parameter. The complexity of the formulation which included Cremophor EL and ethanol may offer an explanation for the observed central neurotoxicity.

Adult↗
PubMed2000

Inter-relationships of paclitaxel disposition, infusion duration and cremophor EL kinetics in cancer patients.

Cremophor EL (CrEL) is a castor oil surfactant used as a vehicle for formulation of a variety of poorly water-soluble agents, including paclitaxel. Recently, we found that CrEL can influence the in vitro blood distribution of paclitaxel by reducing the free drug fraction, thereby altering drug accumulation in erythrocytes. The purpose of this study was to investigate the clinical pharmacokinetics of CrEL, and to examine inter-relationships of paclitaxel disposition, infusion duration and CrEL kinetics. The CrEL plasma clearance, studied in 17 patients for a total of 28 courses, was time dependent and increased significantly with prolongation of the infusion duration from 1 to 3 to 24 h (p<0.03). An indirect response model, applied based on use of a Hill function for CrEL concentration-dependent alteration of in vivo blood distribution of paclitaxel, was used to fit experimental data of the 3 h infusion (r2=0.733; p=0.00001). Simulations for 1 and 24 h infusions using predicted parameters and CrEL kinetic data revealed that both short and prolonged administration schedules induce a low relative net change in paclitaxel blood distribution. Our pharmacokinetic/pharmacodynamic model demonstrates that CrEL causes disproportional accumulation of paclitaxel in plasma in a 3 h schedule, but is unlikely to affect drug pharmacokinetics in this manner with alternative infusion durations.

Antineoplastic Agents, Phytogenic↗
PubMed1999

Current options in treatment of anthracycline-resistant breast cancer.

Breast cancer is a chemosensitive tumour and anthracyclines are one of the most active cytotoxic agents in chemotherapy treatment. Failure after anthracycline-containing chemotherapy is a poor prognostic factor because of low response rate to salvage chemotherapy. Several factors like P-glycoprotein mediated drug resistance (MDR-1 or MRP), glutathione or amplification of topoisomerase II have been found to be involved in anthracycline resistance. No clear benefit for patients treated with 'resistance-modifier' agents like verapamil, dexverapamil or quinidine has yet been demonstrated. Most clinical studies with non-cross resistant cytotoxic agents are lacking a strict definition of anthracycline resistance. A strict definition of anthracycline resistance implies progressive disease during anthracycline chemotherapy. Among the cytotoxic drugs only 5-Fluorouracil (given as 24 h continuous infusion with folinic acid) and the taxanes produce more than 20% objective remission (RR) in case of anthracycline resistance, whereas the highest response rate was reported for docetaxel (32-57%). Only few randomized studies were performed: docetaxel showed higher anti-tumor activity than methotrexat/5-FU (RR: 42% vs 19%, P<0.001) or mitomycin/vinblastine (RR: 30% vs 12%;P<0.001) and treatment with paclitaxel (175 mg/m(2)) was in favour to mitomycin (RR 17% vs 6%). In combination chemotherapy most activity have been reported for paclitaxel plus high-dose 5-fluorouracil (given as 24 h continuous infusion with folinic acid) (RR: 58%) or for docetaxel plus cisplatinum (RR: 46%). High-dose regimens with growth factor or stem cell support seems to be active in anthracycline-resistant disease but the toxicity is considerable. In conclusion, the taxanes, especially docetaxel as single agent or paclitaxel plus high-dose 5-FU, are the most promising therapeutic options in treatment of anthracycline resistant disease. Further clinical phase II/III studies in breast cancer should include exact definition of anthracycline pretreatment and resistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1999

Phase II study with 5-fluorouracil and ginkgo biloba extract (GBE 761 ONC) in patients with pancreatic cancer.

The aim of the study was to evaluate the efficacy and tolerability of as well as the quality of life under treatment with 5-fluorouracil (CAS 51-21-8, 5-FU) combined with parenteral GBE 761 ONC (i.e. the ginkgo biloba special extract EGb 761) in patients with pancreatic cancer. Forty-eight patients with locally or metastatic advanced pancreatic cancer were treated within a phase II study. The treatment was repeated every three weeks until progression. Response to therapy was evaluated after 2 and 4 treatment courses. Thirty-two patients were evaluable for response. Progressive disease was observed in 22 (68.8%) patients, no change in 7 (21.9%) patients and partial response in 3 (9.4%) patients (overall response = 9.4%). GBE 761 ONC was well tolerated. Adverse events which occurred during the study consisted mainly of myelosuppression and gastrointestinal symptoms and were judged as 5-FU-related or consisted of liver toxicity, respectively, and were judged as tumour-related. These results suggest a good benefit-risk ratio of the combination of 5-FU and GBE 761 ONC in the treatment of pancreatic cancer. In comparison with the results of studies with either 5-FU or gemcitabine as single agents the combination of 5-FU/GBE 761 ONC shows comparable response rates. The toxicity of the 5-FU/GBE 761 ONC combination was low. This combination therapy therefore warrants further clinical investigation, such as a controlled clinical trial against 5-FU or gemcitabine monotherapy.

Adolescent↗
PubMed1999

Topotecan - A novel topoisomerase I inhibitor: pharmacology and clinical experience.

Topotecan, a water-soluble analogue of camptothecin, is a newly available cytotoxic agent which acts as an inhibitor of topoisomerase I, an enzyme necessary for DNA replication. Topotecan is a semisynthetic product derived from camptothecin, which was discovered during a National Cancer Institute cytotoxic drug screening program almost 30 years ago. It acts by forming a stable covalent complex with the DNA/topoisomerase I aggregate, the so-called 'cleavable complex'. This process leads to breaks in the DNA strand resulting in apoptosis and cell death. Topotecan possesses a serum half-life of approximately 3 h, a high volume of distribution with high tissue uptake and a low protein binding. The chemical structure is based on a lactone ring. Topotecan undergoes reversible hydrolysis from its biologically active lactone form to the open ring inactive carboxylate form. It is also able to penetrate the intact blood-brain barrier. Since most of the agent is excreted by the kidneys, dose adjustment is necessary when renal function is impaired. In contrast, pharmacokinetic behavior is unchanged in patients with limited hepatic function. The principal toxicity of topotecan when administered at standard doses is neutropenia, but thrombocytopenia and anemia occur as well, while the nonhematological toxicities are usually mild. Alopecia is frequently observed and some patients may suffer from pronounced fatigue. Most clinical data available are based on the following schedule: 1.5 mg/m2 topotecan given as a 30-min infusion, days 1-5. There are currently only minimal data available regarding a dose-antitumor activity relationship. Other topotecan administration schedules are currently being investigated. Preclinical data suggest that continuous-infusion schedules may be a better application form in terms of both, toxicity and antitumor activity. However, clinical trials could not confirm these results to date. Results of phase II studies suggest considerable antitumor activity of single agent topotecan in small cell lung cancer and ovarian cancer patients. A randomized phase III trial of topotecan versus paclitaxel in ovarian cancer patients pretreated with cisplatin/cyclophosphamide has demonstrated that topotecan is as effective as paclitaxel in the second-line treatment of these patients. Activity of topotecan was also observed in non-small-cell lung cancer, refractory leukemias/myelodysplastic syndromes and in childhood sarcomas. Due to its unique mechanism of action and lack of cross-resistance, cisplatin, etoposide, cytarabine and paclitaxel are potential interacting partners for combination chemotherapy regimens. However, the best combination regimen as well as the optimal combination schedule have yet to be conclusively determined. The potential of topotecan in a variety of solid tumors, as well as its use in combination regimens for ovarian and small cell lung cancer is currently being investigated.

Antineoplastic Agents↗
PubMed1998

Linearized colorimetric assay for cremophor EL: application to pharmacokinetics after 1-hour paclitaxel infusions.

Cremophor EL (CrEL) is a polyoxyethylated castor oil surfactant used in the intravenous formulation of the anticancer drug paclitaxel (Taxol). Quantitative determination of CrEL in patient samples can be achieved by complexation of the compound with the Coomassie brilliant blue G-250 dye in protein-free extracts [Sparreboom, A., Loos, W. J., Verweij, J., De Vos, A. I., Van der Burg, M. E. L., Stoter, G., and Nooter, K., Anal. Biochem. 255, 171-175 (1998)]. A disadvantage of this method of CrEL determination is that the assay plot of absorbance at 595 nm, the peak wavelength of the CrEL-dye complex, versus the concentration of the surfactant is not linear. The present study shows that the nonlinearity is associated with a decrease in the free dye concentration and a reduction in complex formation by increasing the CrEL concentration. By measurement of the ratio of absorbances at the maxima of the red (450 nm) and blue charge forms (595 nm) of Coomassie brilliant blue G-250, a full-scale linear relationship can be obtained over the entire range studied (0.500 to 10.0 microliter/mL). Validation data revealed that transformation of the detection procedure exhibits significantly improved specificity, accuracy(</= 6.33% relative error), and precision (< 10.0%) compared to our previous assay. The modified method was successfully applied to the measurement of CrEL in plasma of 11 cancer patients treated with a 1-h infusion of paclitaxel.

Antineoplastic Agents, Phytogenic↗
PubMed1998

Clinical phase I study with one-hour paclitaxel infusion.

BACKGROUND: Paclitaxel (PAC) is one of the major anti-cancer drugs, effective in different tumors. Studies with 24-hour infusion with 135 mg/m2 and a three-hour infusion with 175 mg/m2 showed a significant schedule-dependent toxicity. We evaluated a one-hour infusion schedule within a phase I study to determine the dose limiting toxicity (DLT), the maximum tolerated dose (MTD), and the anti-cancer efficacy. PATIENTS AND METHODS: Patients with advanced malignant tumors were treated within cohorts by one-hour infusional paclitaxel starting with 150 mg/m2 and stepwise escalation with 25 mg/m2 increments. Therapy was repeated in three-week intervals. Cycles were repeated until progression. Toxicity was closely monitored, anti-cancer efficacy was only evaluated in those patients who received at minimum two treatment cycles. RESULTS: Thirty-four patients entered the study (11 NSCLC, five SCLC, seven ovarian cancer, one cervix cancer, nine MBC, one HN cancer). The MTD was PAC 250 mg/m2. The DLT was central and peripheral neuropathy (WHO grade 3). Other significant toxicities were fatigue, myalgia/arthralgia and paraesthesia. No significant myelotoxicity was observed. Totally twentyone patients were evaluable for response. A partial response was observed in five (24%) patients (two NSCLC, two ovarian cancer, one head and neck cancer). Three (14%) patients had stable disease and in 13 (62%) patients progressive disease was observed. CONCLUSIONS: Paclitaxel 225 mg/m2 on day 1 administered as one-hour infusion and repeated every three weeks can be given safely, featured no relevant myelotoxicity, and is the recommended dose for phase II studies.

Adult↗
PubMed1998

Clinical and pharmacologic phase I study of Cemadotin-HCl (LU103793), a novel antimitotic peptide, given as 24-hour infusion in patients with advanced cancer. A study of the Arbeitsgemeinschaft Internistische Onkologie (AIO) Phase I Group and Arbeitsgruppe Pharmakologie in der Onkologie und Haematologie (APOH) Group of the German Cancer Society.

PURPOSE: To determine the maximum tolerable dose (MTD), principal toxicity, and pharmacologic behaviour of Cemadotin-HCl, a novel antimitotic peptide. PATIENTS AND METHODS: Cemadotin-HCl (10.0 to 27.5 mg/m2/day every three weeks) was administered as a 24-hour intravenous (i.v.) continuous infusion to patients with advanced cancer. Pharmacokinetic analyses were performed during the first treatment cycle. Blood samples were taken over 48 hours and analyzed by radioimmunoassay. RESULTS: Hypertension was the dose-limiting toxicity (DLT). This type of toxicity was observed at all dose levels, but grade 3 (CTC) was observed only at dose levels 20.0, 25.0 and 27.5 mg/m2. This effect was reversible but in three patients associated with signs of cardiac ischemia. Other significant toxic effects were neutropenia, asthenia, tumor pain and transient liver enzyme elevation. A linear pharmacokinetics was observed. The best curve fit was obtained with a two-compartment model with a terminal half-life of approximately 10 hours at each dose level, a volume of distribution at steady state of approximately 9 l/m2 and a total clearance of approximately 0.6 l/hour/m2. Neither partial nor complete responses were observed although minor tumor regressions were seen in a patient with carcinoma of unknown primary (CUP) and in another patient with liver metastases from a colon cancer. CONCLUSIONS: Hypertension was the dose-limiting toxicity of Cemadotin-HCl administered as a continuous 24-hour infusion. The recommended dose for further evaluation of its anticancer efficacy in disease-oriented phase II studies with this schedule is 15.0 mg/m2. The nature of the principal cardiovascular toxicity remains unclear. The observed toxicities appeared to be significant but manageable.

Adult↗
PubMed1998

Phase II trial of dexverapamil and epirubicin in patients with non-responsive metastatic breast cancer.

Agents capable of reversing P-glycoprotein-associated multidrug resistance have usually failed to enhance chemotherapy activity in patients with solid tumours. Based on its toxicity profile and experimental potency, dexverapamil, the R-enantiomer of verapamil, is considered to be promising for clinical use as a chemosensitizer. The purpose of this early phase II trial was to evaluate the effects of dexverapamil on epirubicin toxicity, activity and pharmacokinetics in patients with metastatic breast cancer. A two-stage design was applied. Patients first received epirubicin alone at 120 mg m(-2) i.v. over 15 min, repeated every 21 days. Patients with refractory disease continued to receive epirubicin at the same dose and schedule but supplemented with oral dexverapamil 300 mg every 6 h x 13 doses. The Gehan design was applied to the dexverapamil/epirubicin cohort of patients. Thirty-nine patients were entered on study, 25 proceeded to receive epirubicin plus dexverapamil. Dexverapamil did not increase epirubicin toxicity. The dose intensity of epirubicin was similar when used alone or with dexverapamil. In nine intrapatient comparisons, the area under the plasma concentration-time curve (AUC) of epirubicin was significantly reduced by dexverapamil (mean 2968 vs 1901 microg ml[-1] h[-1], P= 0.02). The mean trough plasma levels of dexverapamil and its major metabolite nor-dexverapamil were 1.2 and 1.5 microM respectively. The addition of dexverapamil to epirubicin induced partial responses in 4 of 23 patients evaluable for tumour response (17%, CI 5-39%, s.e.P 0.079). The remissions lasted 3, 8, 11 and 11+ months. These data suggest that the concept of enhancing chemotherapy activity by adding chemosensitizers may function not only in haematological malignancies but also in selected solid tumours. An increase in the AUC and toxicity of cytotoxic agents does not seem to be a prerequisite for chemosensitizers to enhance anti-tumour activity.

Adult↗
PubMed1997

Phase I study of paclitaxel administered as a 1-hour infusion: toxicity and pharmacokinetics.

Paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) is one of the most important new drugs used in the treatment of solid tumors. Use of paclitaxel, however, is associated with some toxicity. The main adverse side effects include myelotoxicity, neurotoxicity, hypersensitivity reactions, and asthenia. Toxicity seems to be schedule dependent. Currently, paclitaxel is routinely administered via 3- or 24-hour infusions. This study was performed to evaluate the toxicity and pharmacokinetics of a 1-hour infusion. Thirty-four patients with incurable solid tumors were included. Dose levels were escalated from 150 to 250 mg/m2. Thirty-four patients received a total of 105 courses of paclitaxel. The dose-limiting toxicity was World Health Organization grade 3 neuropathy at a dose of 250 mg/m2 in two of three patients. Two patients were not evaluable for dose-limiting toxicity because treatment was stopped after fewer than three courses due to disease progression. Neither had experienced a dose-limiting toxicity. Other toxicities were World Health Organization grade 1/2 neutropenia, asthenia, myalgia, arthralgia, and grade 1 hypersensitivity. Twenty-one patients were evaluable for preliminary anticancer efficacy. A partial response was observed in five patients (24%), stable disease in three (14%), and progressive disease in 13 (62%). The maximum tolerated dose was established at 250 mg/m2. A dose of 225 mg/m2 is recommended for further phase II trials. There was considerable interindividual and some intraindividual variability in pharmacokinetic parameters. Paclitaxel pharmacokinetics were linear up to 225 mg/m2, while a slightly overproportional increase in the peak plasma concentration and the area under the concentration-time curve was observed at 250 mg/m2, suggesting that paclitaxel's pharmacokinetic characteristics may be nonlinear at higher doses.

Adolescent↗
PubMed1996

Reverse transcriptase/polymerase chain reaction detection of cytokeratin-19 mRNA in bone marrow and blood of breast cancer patients.

A two-step reverse-transcriptase-based polymerase chain reaction (PCR) with nested primer pairs was developed to amplify sensitive and specific cytokeratin-19 (CK-19) mRNA sequences from human breast cancer cells. No CK-19 pseudogene interference was seen. The larger DNA-derived amplification products could be clearly discriminated from mRNA-derived products. The CK-19 message was not amplified from bone marrow or blood of healthy volunteers and patients with haematological malignancies nor from myeloid and lymphoid cell lines. Breast cancer cells were diluted in buffy coat cells up to 10(-6) and CK-19 mRNA sought by PCR. The CK-19 message was detected in 14 of 26 blood samples and 14 of 24 marrow samples but in neither of two peripheral blood stem cell samples taken from 35 breast cancer patients. By sequence-analysis control of two of these samples and two cell lines, the amplified DNA fragments were confirmed to be homologous with the CK-19 sequence. The CK-19 message was further sought in matched blood/marrow samples taken from 13 untreated women in the same cohort at the time of diagnosis. In 3 of these, CK-19 RNA was detected in blood and marrow and, in 3 others, only in blood, but never in marrow alone. The results show that CK-19 assay by reverse transcriptase/PCR is a sensitive and specific technique for the detection of cancer cells in bone marrow and blood. It could be helpful in diagnosis and monitoring of metastatic breast cancer and detection of micrometastases. This should be evaluated on larger numbers of patients, with different clinical samples and epithelial malignancies.

Base Sequence↗
PubMed1996

Pharmacokinetics and pharmacodynamics of the new podophyllotoxin derivative NK 611. A study by the AIO groups PHASE-I and APOH.

NK 611 is a new podophyllotoxin derivative in which a dimethyl amino group replaces a hydroxyl group at the sugar moiety of etoposide. This results in profound physico-chemical differences: NK 611 is much less hydrophobic than etoposide. Preclinical studies have shown that NK 611 is advantageous in terms of bioavailability and of the potency of its anticancer activity. A clinical phase I study was performed in cancer patients within the framework of the AIO. Additionally, its pharmacokinetics and pharmacodynamics were investigated. NK 611 was given to 26 patients at doses ranging from 60 to 140 mg/m2 [maximum tolerated dose (MTD) 120 mg/m2] in a 30-min infusion. Plasma and urine samples were collected from 25 patients and analyzed using a validated high-performance liquid chromatography (HPLC) assay procedure. The concentration versus time curve of total NK 611 in plasma samples was best described by a three-compartment model. The overall median pharmacokinetic values were as follows (ranges are given in parentheses): mean residence time (MRT) 16.5 (5.4-42.3)h, terminal half-life 14.0 (8.2-30.5)h, volume of distribution at steady state (V(ss)) 11.4 (7.9-18.1) l/m2 and plasma clearance (Cl(p)) 15.1 (3.6-36.4) ml min-1 m-2. The total systemic drug exposure, represented by the area under the curve (AUC), varied between 53.4 and 532.0 micrograms ml-1 h. The mean AUC (+/- SD) increased with the dose from 78.7 +/- 3.7 micrograms ml-1 h at 60 mg/m2 up to 202.8 +/- 157.2 micrograms ml-1 h at 120 mg/m2. The mean urinary excretion (UE) fraction of unchanged drug at 48 h after the end of the infusion varied between 3.0% and 25.8% of the total dose delivered. Analysis of ultrafiltrate samples showed a protein binding of approx.. 99%. The percentage reduction in white blood cells (WBC) and neutrophils (ANC) correlated with the dose, AUC, and AUC(free). The best relationship between the percentage of reduction in ANC and a pharmacokinetic parameter (AUC) took a nonlinear Hill-type form. The laboratory parameter for kidney or liver function did not correlate with the AUC. The variation of pharmacokinetic parameters within each dose level was profound. The reason for this pharmacological behavior remains unclear and should be investigated in further studies.

Adult↗
PubMed1996

The pharmacokinetics and toxicity of two application schedules with high-dose VP-16 in patients receiving an allogeneic bone marrow transplantation.

BACKGROUND: Etoposide is one of the few drugs being used in conditioning regimens because of the ease with which its dosage can be escalated by a factor of 6 compared to the normal dose. The best schedule in high-dose chemotherapy is not known. PATIENTS AND METHODS: We evaluated the pharmacokinetics (PK) of high-dose VP-16 during two different schedules (6-hour and 3 x 1-hour infusions) and the toxicity of the two application modes in patients with leukemia who underwent allogeneic bone marrow transplantation. RESULTS: A significant difference (p = 0.008) in the volume of distribution at steady state was observed. The mean Vss was 0.21 L/kg in the 6-hour group and 0.36 in the 3 x 1-hour group. The total drug exposure time with plasma levels > 100 ng/ml is significantly longer in the 'split' group (74 vs. 143 h). Other PK parameters such as plasma clearance and area under the curve were not significantly different. Leukocyte recovery to WBC levels > 0.2 and > 0.5/nl as well as platelet recovery to stable counts > 50/nl was significantly (p = 0.002, 0.009 and 0.04) prolonged in the 'split' group (3.7 vs. 12.3, 8.3 vs. 14.3 and 25 vs. 35 d). The liver toxicity as indicated by bilirubin peak levels was significantly (p = 0.02) more severe in the 'split' group (1.7 vs. 5.4 mg/dl). CONCLUSION: The area under the curve as a measure of total drug exposure cannot be correlated to the observed higher toxicity in the patient group with the 'split' application mode. The drug exposure time as well as the three high peak plasma levels may be more important.

Antineoplastic Agents, Phytogenic↗
PubMed1996

Fatal outcome of disseminated candidosis after allogeneic bone marrow transplantation under treatment with liposomal and conventional amphotericin-B. A report of 4 cases with determination of the Mic values.

Four patients undergoing allogeneic bone marrow transplantation were treated with liposomal (3 patients) and conventional (one patient) amphotericin-B for disseminated candidosis. Candida krusei was isolated from 3, and C. glabrata from 1 patient. The patients were treated with liposomal amphotericin-B in doses from 3 to 5 mg/kg. The fourth patient received conventional amphotericin-B in a reduced dose due to renal impairment. The patients died from multiorgan failure due to disseminated fungal infection. In 1 case, the switch to the conventional drug resulted in clearance before death. The 3 fungus isolates, together with the fourth strain obtained from patient no. 4 without any exposition to liposomal amphotericin-B were tested for their susceptibility to conventional, liposomal and discoidal amphotericin-B. All strains showed good sensitivity to the conventional and discoidal drug. The minimal inhibitory concentrations (MIC) of liposomal amphotericin-B were 1 to 3 titre steps higher indicating a reduced sensitivity of the tested strains to this preparation. We conclude that the use of liposomal amphotericin-B is recommended mainly on the base of the low incidence of side-effects. Intensive microbial resistance tests, pharmacokinetic investigations and randomized studies are necessary before the conventional drug is replaced as the gold standard for systemic antimycotic therapy.

Adult↗