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Biomedical subjects

H Burkert

Publications and source records attributed to H Burkert.

11 recordsLinked to original sources
PubMed1984

Bioavailability of orally administered mesna.

The bioavailability of orally administered sodium 2-mercaptoethane sulfonate (mesna, Uromitexan drink ampoules) was tested in 18 healthy probands and in 5 tumor patients. Following single oral administration of 20 or 40 mg/kg mesna, 52.4% and 52.6%, respectively, of the dose were excreted in the urine as reactive thiol groups, the remainder as mesna disulfide (dimesna), the only metabolite of mesna; after i.v. injection of 20 mg/kg mesna, 48.7% of the dose administered appeared as thiol groups in the urine. Not until after 13.1 h (20 mg/kg p.o.) and 18.5 h (40 mg/kg p.o.), respectively, concentration drops below the minimum concentration of 100 micrograms/ml presumed to be still reliably protective. However, the elimination pattern and the time when the threshold concentration is reached are subject to marked individual variation. After i.v. administration of 20 mg/kg mesna and 9 times oral administration of 20 mg/kg mesna (the first dose concurrently with the i.v. injection, thereafter every 4 h), or 7 times oral administration of 20 mg/kg mesna (the first dose again concurrently with the i.v. injection, thereafter every 5 h), the percentage of the total dose administered appearing as thiol groups in the urine averaged 41.9% and 37.6%, respectively, up to 17 or 18 h after the last dose. Comparison of periods covering the same time of the day showed the total amount excreted to be higher on day 2 than on day 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1983

Clinical overview of mesna.

Mesna is superior to standard prophylaxis in inhibiting the urotoxicity of oxazaphosphorines. Mesna does not interfere with the antitumour effect of oxazaphosphorines and other cytostatics. Mesna is well tolerated. Mesna can be given orally. Mesna should be administered with each ifosfamide treatment and with high dose cyclophosphamide. It should also be given to any patient who may be at risk of developing cystitis following oxazaphosphorine treatment.

Clinical Trials as Topic↗
PubMed1979

[Prevention of urinary tract toxicity of oxazaphosphorines by a "uroprotector". Report on a field study (author's transl)].

In an open multicenter phase III trial, prophylaxis of the urinary tract with sodium 2-mercaptoethanesulfonate (Mesnum) was carried out in 242 patients treated with oxazaphosphorines for various malignant tumors. Under the protection of Mesnum 29 patients were treated with cyclophosphamide (Endoxan), 195 with ifosfamide (Holoxan) and 8 with trofosfamide (Ixoten). Other cytostatics were also used (polychemotherapy) in 92 cases. On administration of Mesnum, 7 macrohematurias reappeared, only 3 of them however with correct application, and 22 microhematurias, 12 of them with correct application. Cylindrurias were re-established in 3 patients. In Mesnum we have a compound which can control the urotoxicity ("uroprotector") of oxazaphosphorines which limits their therapeutic use.

Adolescent↗
PubMed1979

Controlled clinical studies with an antidote against the urotoxicity of oxazaphosphorines: preliminary results.

A randomized study in 20 patients with cancer was carried out to test the clinical efficacy of sodium-2-mercaptoethane sulfonate (ASTA D-7093; mesnum) as an agent to prevent urotoxic side effects (in particular, hemorrhagic cystitis) during cytostatic therapy with the oxazaphosphorines cyclophosphamide and ifosfamide. Eleven patients received mesnum iv and nine patients received a standard prophylaxis. The frequency of microhematuria was significantly lower in the patients receiving mesnum. A slight microhematuria was observed in one patient. With the standard prophylaxis, all nine patients receiving single-agent therapy with ifosfamide or cyclophosphamide had hematuria and three of these had macrohematuria. According to the available results, a daily mesnum dose of 60% (wt/wt) of the ifosfamide or cyclophosphamide dose is recommended. This dose should be divided into three equal fractions. The first administration should be given concurrently with the cytostatic agent and the subsequent two administrations at 4 and 8 hours after administration of the cytostatic agent. Significantly higher doses of mesnum (eg, 133% of the cyclophosphamide or ifosfamide doses) lead to gastrointestinal disorders, which are easily reversible.

Clinical Trials as Topic↗
PubMed1976

Evaluation of a cooperative clinical study of the cytostatic agent ifosfamide.

In cooperative studies performed in 21 German clinics, the new cytostatic agent 3-(2-chloroethyl)-2-[(2-chloroethyl)-amino]-tetrahydro-2H-1,3,2-oxazaphosphorine-2-oxide (ifosfamide; trade name: Holoxan) was administered as massive-dose treatment. The studies aimed at confirming the results obtained in pharmacological and Phase I clinical trials with a fractionated administration of ifosfamide on a large scale. The study was carried out in 390 patients suffering from various malignant conditions. The majority of patients had had pretreatment without response or were admitted at an advanced stage of disease. Despite this negative selection, 25.5% of the patients showed an initial full remission and 42.3% partial remission; in 32.2% of the patients, reduction of the tumour signs by at least 50% was not attained. After an average observation period of 6 1/2 months, 53.8% of the patients were still alive. The study clearly shows the superiority of fractionated administration of ifosfamide when compared to its use as a single administration. In addition, the rates of remission and survival, and of survival times, were clearly dependent on dosage, independent of the tumour type. A daily dosage of 50 to 60 mg/kg ifosfamide on 5 consecutive days produced the best results. In spite of the fact that ifosfamide was not always given at optimum dosage, it proved to be definitely superior to conventional chemotherapy in testicular tumours, particularly teratomas and also in hypernephromas. Retrospective comparison with results of conventional chemotherapy for ovarian, bronchial and mammary cancer has shown ifosfamide to produce the same therapeutic effect in these tumour types. In this study group, leukopenia was not regarded as a limiting factor to the administration of ifosfamide. Side effects in the efferent urinary tract, particularly cystitis, were controlled with adequate preventive measures.

Adenocarcinoma↗
PubMed1975

[Results of the synchronization therapy with vincristine and cyclophosphamide in lymphogranulomatosis, reticulum cell sarcoma and lymphosarcoma. A phase II study (author's transl)].

The effectiveness of synchronization therapy was tested on 88 patients who had already undergone some form of treatment for lymphogranulomatosis (stage III B and IV), generalized reticulum cell sarcoma or lymphosarcoma. This therapeutical concept is based on a partial synchronic increase in tumor cells induced by noncytocidal doses of vincristine, followed by cytostatic or cytocidal treatment with cyclophosphamide during DNA synthesis of the partially synchronized tumor cells. The therapeutic plan is similar to a single-agent therapy. In lymphogranulomatosis, complete remission could be achieved in 14 out of 19 cases (stage III B) and in 9 out of 24 cases (stage IV). The mean remission period during an orally administered cytostatic maintenance therapy was 15 1/2 months. The highest rate of remission was found in the mixed cell type of granulomas (23 out of 24 patients). In the non-Hodgkin's lymphomas, complete remission was achieved in 13 out of 30 cases (lymphosarcoma) and in 19 out of 15 cases (reticulum cell sarcoma). The mean remission period for orally administered cytostatic maintenance therapy was 16 months for lymphosarcoma and 11 1/2 months for reticulum cell sarcoma. These therapeutic results are comparable to those achieved by very effective schemes of combination chemotherapy but the toxic side-effects of synchronization therapy are considerably lower.

Adolescent↗