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1.
Transplant Proc ; 37(8): 3260-1, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16298565

RESUMO

Hungarotransplant Public Service Corporation, the national organ exchange organization, was established in 2001. The assessment of donation- and transplantation-related data allows the evaluation of the current situation and future trends. The donor reports show involvement of new hospitals and an increase in reported donors. These results are due to a new centralized organ referral system implemented by Hungarotransplant, employment of donation links in donor hospitals, training for key persons in intensive care units, and implementation of a Donor Action program, generating frequent and positive media attention. In 2002 the number of realized cadaveric donors increased by 21% and remained stable in 2003 despite the further increase in referrals. In 2002 the number of heart transplants remained the same, and liver transplant activity declined. In contrast, in 2003 the heart transplant activity rose by 33% and liver transplant activity by 82%. The multiorgan donation rate and the total number of transplanted organs have increased continuously. Our data demonstrate that organized multilateral efforts resulted in an immediate improvement in donation-transplantation activity in Hungary. However, the role of factors other than the shortage of organs, such as capacity problems and limited financial resources, are also highlighted.


Assuntos
Transplante de Órgãos/estatística & dados numéricos , Doadores de Tecidos/estatística & dados numéricos , Obtenção de Tecidos e Órgãos/métodos , Cadáver , Humanos , Hungria , Doadores Vivos/estatística & dados numéricos , Obtenção de Tecidos e Órgãos/tendências
2.
Anticancer Drugs ; 9(9): 765-72, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9840721

RESUMO

The effect of etoposide on the pharmakokinetics of methotrexate (MTX) was examined in vivo. High-dose (5g/m2/24 h) MTX therapy was combined with two etoposide (100mg/m2/ 1 h) infusions as a part of the medulloblastoma protocol developed in our department. Vepesid therapy was administered in two different schedules. The first group of patients received etoposide immediately before and at the end (24 h) of MTX treatment. The second group was treated with etoposide at 24 and at 48 h after starting MTX infusion. In this latter group both treatment-related grade III and grade IV toxicity developed more frequently than in the first group (58.6 versus 29.2%, for grade 3 toxicity p=0.019, for grade 4 toxic signs p=0.040, respectively). We observed that after the second dose of etoposide given at 48 h (second group) both total and unbound serum MTX levels (determined by high-performance liquid chromatography) were elevated by 53-109 and 26-65%, respectively, by the third hour after completion of Vepesid infusion. This effect was detectable for 6 h. All the liver and kidney functions of the patients were within the normal range. These results suggest the possibility of partial recirculation of extra/intracellular MTX into the blood after etoposide administration. Based on these results, the therapeutic protocol has been modified, and Vepesid is given prior to and at the end (24 h) of high-dose MTX treatment. Under these conditions only a slight decrease of MTX elimination has been detected between 25 and 28 h. These results emphasize the role of possible schedule-dependent interactions of cytostatic drugs.


Assuntos
Antimetabólitos Antineoplásicos/sangue , Antineoplásicos Fitogênicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Encefálicas/sangue , Neoplasias Encefálicas/tratamento farmacológico , Etoposídeo/farmacologia , Meduloblastoma/sangue , Meduloblastoma/tratamento farmacológico , Metotrexato/sangue , Adolescente , Antimetabólitos Antineoplásicos/administração & dosagem , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/sangue , Protocolos de Quimioterapia Combinada Antineoplásica/sangue , Neoplasias Encefálicas/radioterapia , Criança , Cisplatino/administração & dosagem , Terapia Combinada , Relação Dose-Resposta a Droga , Esquema de Medicação , Interações Medicamentosas , Etoposídeo/administração & dosagem , Etoposídeo/sangue , Humanos , Leucovorina/administração & dosagem , Meduloblastoma/radioterapia , Metotrexato/administração & dosagem , Mitolactol/administração & dosagem , Procarbazina/administração & dosagem
3.
Eur J Cancer ; 34(3): 364-7, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9640223

RESUMO

This prospective, randomised pilot study was designed to evaluate safety, feasibility and efficacy of recombinant human erythropoietin (rhEPO) in the prevention and treatment of chemotherapy-induced anaemia in children with solid tumours. 20 children (age 4-18 years) undergoing cyclic combination chemotherapy were randomised either to a control group or to receive rhEPO at a dose of 150 U/kg/dose subcutaneously three times/week for a minimum of 12 weeks or three chemotherapy cycles. Of 15 evaluable patients, 8 were randomised to the rhEPO group and 7 to the control group. RhEPO-treated patients showed an increase in the haematocrit over the first 8 weeks of therapy, with a significantly higher mean haematocrit at week 8 (33.2 +/- 2.1% versus 39.3 +/- 4.2% in the control and rhEPO groups, respectively, P < 0.05). Similarly, significantly higher haemoglobin concentrations could be demonstrated in the rhEPO group by week 8 (11.06 +/- 1.35 g/dl versus 13.11 +/- 1.13 g/dl in the control and rhEPO groups, respectively, P < 0.05), with higher precycle haemoglobin before chemotherapy cycles 3 and 4 and higher midcycle haemoglobin between cycles 3 and 4. There was a trend towards a reduction of transfusion requirements during the 3rd month of therapy in rhEPO patients. The results of this pilot study indicate a significant benefit of rhEPO in children treated with intensive combination chemotherapy regimens. Further studies should target issues such as appropriate dosing, timing and duration of rhEPO therapy in children with cancer.


Assuntos
Anemia/prevenção & controle , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Eritropoetina/uso terapêutico , Adolescente , Anemia/sangue , Anemia/induzido quimicamente , Transfusão de Sangue , Criança , Pré-Escolar , Ferritinas/sangue , Hemoglobinas/análise , Humanos , Ferro/sangue , Projetos Piloto , Estudos Prospectivos , Proteínas Recombinantes , Redução de Peso
4.
J Clin Oncol ; 16(3): 966-78, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9508179

RESUMO

PURPOSE AND METHODS: Future progress in the care of children with cancer requires appropriate evaluations of promising new agents for pediatric indications, beginning with well-conducted phase I trials. This report summarizes current guidelines for the conduct of pediatric phase I trials and represents a consensus between American and European investigators. The primary objective of pediatric phase I trials is to define safe and appropriate doses and schedules of new agents that can subsequently be used in phase II trials to test for activity against specific childhood malignancies. Prioritization of agents for evaluation in children is critical, since many more investigational agents are evaluated in adult patients than can be systematically evaluated in children. Considerations used in prioritizing agents include activity in xenograft models, novel mechanism of action, favorable drug-resistance profile, and activity observed in adult trials of the agent. RESULTS AND CONCLUSION: Distinctive characteristics of pediatric phase I trials, in comparison to adult phase I trials, include the necessity for multiinstitutional participation and their higher starting dose (typically 80% of the adult maximum-tolerated dose [MTD]), both of which reflect the relative unavailability of appropriate patients. The application of uniform eligibility criteria and standard definitions for MTD and dose-limiting toxicity (DLT) help to assure that pediatric phase I trials are safely conducted and reliably identify appropriate doses and schedules of agents for phase II evaluation. Where possible, pediatric phase I trials also define the pharmacokinetic behavior of new agents in children.


Assuntos
Antineoplásicos/uso terapêutico , Ensaios Clínicos Fase I como Assunto/normas , Neoplasias/terapia , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacocinética , Criança , Pré-Escolar , Guias como Assunto , Humanos , Lactente
7.
Med Pediatr Oncol ; 26(5): 367-71, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8614371

RESUMO

The use of granulocyte colony-stimulating factor (G-CSF) or granulocyte-macrophage colony-stimulating factor (GM-CSF) in order to abrogate chemotherapy-induced neutropenia has become a routine part of many cancer treatment regimes. However, there are still very few data available about possible complications related to repeated or prolonged use of these agents in patients with malignant solid tumors. The authors report a child with brainstem glioma who received repeated cycles of multiagent chemotherapy with G- or GM-CSF support. During this period of 10 months, no clinical side effects were observed that could have been attributed to growth factor administration. However, postmortem histological examination revealed the presence of diffuse plasmacytosis, a rare hematological disorder in childhood. Undifferentiated plasma cells of nonmonoclonal origin could be demonstrated infiltrating bone marrow, lungs, and lymph nodes of the patient. Based on previously published in vitro and in vivo evidence on the interleukin-6 (IL-6)-mediated stimulatory effect of G- and GM-CSF on myeloma cell proliferation, the authors suggest a possible link between extensive growth factor support and the development of plasmacytosis in this patient.


Assuntos
Neoplasias Encefálicas/terapia , Glioblastoma/terapia , Plasmocitoma/terapia , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/radioterapia , Tronco Encefálico/patologia , Terapia Combinada , Evolução Fatal , Glioblastoma/patologia , Glioblastoma/radioterapia , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Fator Estimulador de Colônias de Granulócitos e Macrófagos/uso terapêutico , Humanos , Interleucina-6/uso terapêutico , Imageamento por Ressonância Magnética , Masculino , Plasmocitoma/patologia , Plasmocitoma/radioterapia
8.
Anticancer Drugs ; 7(1): 121-6, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8742109

RESUMO

The first report on the administration of the chemoprotective agent Ethyol (amifostine) in conjunction with high dose carboplatin to a patient in the pediatric/adolescent age group is presented. A 17 year old teenager with recurrent cerebellar medulloblastoma received a total of five courses of high dose carboplatin 2 x 600 mg/m2 (1200 mg/m2 total) in each cycle. A complete response has been observed following the third treatment cycle. However, cumulative grade IV hematological toxicity developed following each of the first four treatments. Therefore, the fifth treatment was administered in conjunction with amifostine, at a dose of 2 x 740 mg/m2. Time to complete hematological recovery (Hb > 100 g/l, granulocytes > 2.0 G/l, platelets > 100 G/l) was 52, 58, 72, 78 and 50 days, respectively, following treatments nos 1, 2,,3, 4 and 5. The duration of grade III-IV neutropenia (< 1.0 G/l) was 3, 7, 8, 10 and 5 days, respectively. The duration of grade II-IV thrombocytopenia (platelets < 75 G/l) was 10, 25, 35, 40 and 32 days, respectively. Grade IV thrombocytopenia (platelets < 25 G/l) lasted for 5, 10, 12, 18 and 3 days, respectively, after each consecutive treatment. The total number of platelet transfusions was 1, 2, 2, 3 and 1, with the transfusion of 6, 9, 11, 11 and 5 units of platelets. The administration of amifostine has not been accompanied by any serious side effect. A short decrease in body temperature and a transient drop of blood pressure have been observed. Although hematological toxicity of high dose carboplatin has not been eliminated by amifostine, we conclude that significant protection was achieved in this situation of progressive bone marrow exhaustion.


Assuntos
Amifostina/uso terapêutico , Antineoplásicos/efeitos adversos , Carboplatina/efeitos adversos , Neutropenia/prevenção & controle , Protetores contra Radiação/uso terapêutico , Trombocitopenia/prevenção & controle , Amifostina/efeitos adversos , Neoplasias Cerebelares/tratamento farmacológico , Criança , Humanos , Masculino , Meduloblastoma/tratamento farmacológico , Neutropenia/induzido quimicamente , Protetores contra Radiação/efeitos adversos , Trombocitopenia/induzido quimicamente
9.
Pediatr Hematol Oncol ; 13(1): 33-44, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8718501

RESUMO

A population-based cancer registry for childhood leukemia was started in Hungary in 1971. Data processing and analysis have been done at the Second Department of Pediatrics, Semmelweis University Medical School in Budapest, which is the main center for the treatment of childhood malignancies in Hungary. In 1992 a new computerized database structure was created in collaboration with Kansas University Medical Center, Kansas City, Kansas, United States. This work presents childhood leukemia frequency distribution and treatment results between 1988 and 1992 in Hungary. The number of patients diagnosed with leukemia under 18 years of age fluctuates between 69 and 82 cases per year. We present the main causes of death and outline our future objectives to improve the survival rate and quality of life.


Assuntos
Leucemia/epidemiologia , Adolescente , Criança , Pré-Escolar , Humanos , Hungria/epidemiologia , Lactente , Recém-Nascido , Leucemia/mortalidade , Taxa de Sobrevida , Fatores de Tempo
10.
Pediatr Hematol Oncol ; 11(6): 641-9, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7857787

RESUMO

Apoptosis (programmed cell death) is a physiologic phenomenon wherein the dying cell plays an active part in its own destruction. It has an important role in regulation of the balance of cell proliferation and cell death. The pharmacologic manipulation of apoptosis offers new possibilities for the prevention and treatment of cancer. One of the independent prognostic factors in the treatment of acute lymphoblastic leukemia is the sensitivity of the leukemic cells to corticosteroids. Apoptosis after glucocorticoid therapy is suggested as a prognostic factor in children with leukemia. Peripheral blood of children with acute leukemia was taken for morphologic and flow cytometric studies before and after the onset of prednisolone monotherapy. In most of the cases a positive correlation was observed between the decrease of blast numbers and the increase in apoptotic ratio in peripheral blood. In one case no response was observed either clinically or regarding apoptosis.


Assuntos
Apoptose , Leucemia-Linfoma Linfoblástico de Células Precursoras/sangue , Prednisolona/uso terapêutico , Adolescente , Criança , Pré-Escolar , Feminino , Citometria de Fluxo , Humanos , Lactente , Recém-Nascido , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Prognóstico
11.
Anticancer Drugs ; 5(5): 539-47, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7858286

RESUMO

Systemic pharmacokinetics of high dose (500 mg/m2), orally administered Elobromol (dibromodulcitol, DBD) were studied in 16 chemotherapeutic courses administered to five patients. Cerebrospinal fluid (CSF) DBD levels were also analyzed in two patients. Bromoepoxydulcitol (BED), dianhydrodulcitol (DAD) are cytotoxic, whereas bromoanhydrodulcitol (BAD) and anhydroepoxydulcitol (AED) are inactive metabolites detectable during the biotransformation of DBD. The HPLC method, developed by our team, is suitable for the determination of both DBD and its main metabolites (DAD and BAD). Our publication is the first in the literature to describe the pharmacokinetic properties of these three hexitol derivatives in pediatric patients. With the exception of one patient, concentration time curves were analyzed by the one-compartment model. From 30 min following administration, DBD was detectable in all plasma samples for at least 12 h; its concentration, however, was usually undetectable by 24 h. Though highly variable in value, DAD concentrations were detectable during all but one of the therapeutic courses. The following peak concentrations were observed: DBD = 3.46-30.63 microM, DAD = 1.70-6.17 microM and BAD = 0-5.63 microM. The correlation of AUCBAD and AUCDBD values were exponential up to 200 microM h with no additional increase detectable above this limit: the distribution of AUCBAD and AUCDBD was described by a maximum curve. The possibility of enterohepatic recirculation could not be excluded for any of the compounds studied. Each of the three hexitol derivatives was detectable in CSF even if the concentration of the individual metabolite remained undetectable in plasma. DBD CSF concentrations were almost constant in the period from 2.5 to 8 h following administration.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Neoplasias Encefálicas/metabolismo , Meduloblastoma/metabolismo , Mitolactol/farmacocinética , Envelhecimento/metabolismo , Biotransformação , Neoplasias Encefálicas/tratamento farmacológico , Criança , Pré-Escolar , Cromatografia Líquida de Alta Pressão , Circulação Êntero-Hepática/fisiologia , Feminino , Meia-Vida , Humanos , Meduloblastoma/tratamento farmacológico , Mitolactol/administração & dosagem
12.
Pediatr Hematol Oncol ; 11(2): 165-72, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8204441

RESUMO

During the period 1979 to 1992 we treated 141 children for various malignant diseases with protocols including methotrexate (MTX) infusions in doses ranging from 0.5 to 33.6 g/m2. During a total of 922 courses, there were no fatal complications associated with MTX treatment. Serum MTX concentration and pharmacokinetic data were monitored continuously during the infusions. In this study, we evaluated the occurrence of serious untoward reactions to MTX infusions. Impaired renal function with delayed drug elimination was seen in seven patients, all boys, especially after short infusion times. All recovered completely without any serious clinical symptoms. In three leukemia patients who later died from resistant disease, we observed late neurological disturbances and computer tomography (CT) brain scan abnormalities. Pharmacokinetic data from the patients with complications are described and confirm that serial MTX concentration monitoring is the most important early indicator of renal toxicity.


Assuntos
Metotrexato/efeitos adversos , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Rim/efeitos dos fármacos , Masculino , Metotrexato/administração & dosagem , Metotrexato/farmacocinética , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico
13.
Pediatr Hematol Oncol ; 11(2): 201-5, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8204446

RESUMO

This paper reports preliminary experiences with human recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF) in children with malignant diseases administered for three indications: (1) chemotherapy-induced neutropenia and sepsis, (2) prolonged neutropenia decreasing dose intensity, and (3) prevention of neutropenia after sublethal doses of chemotherapy. It was concluded that in the daily dose of 5 micrograms/kg subcutaneously, GM-CSF is capable of reducing the duration of chemotherapy-induced neutropenia and may be an effective tool in maintaining dose intensity and achieving dose escalation.


Assuntos
Fator Estimulador de Colônias de Granulócitos e Macrófagos/uso terapêutico , Neoplasias/terapia , Neutropenia/terapia , Adolescente , Criança , Pré-Escolar , Humanos , Lactente , Neutropenia/prevenção & controle , Proteínas Recombinantes/uso terapêutico
14.
Cancer Chemother Pharmacol ; 33(3): 262-3, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8269609

RESUMO

One of the major complications after high-dose methotrexate (HDMTX) infusions is renal damage. We investigated the occurrence of proteinuria after HDMTX administration in children with pediatric malignancies (acute lymphoid leukaemia, osteosarcoma Burkitt's lymphoma). In the period 1989-1990 we gave 52 HDMTX courses to 24 children. During this period, prehydration and extra urinary alkalisation were performed only if the urinary specific gravity was over 1010 or if the urinary pH fell below 7. Using this schedule the mean values obtained for protein extraction were: before the therapy, 0.12 +/- 0.03 g/m2; on day 1 after MTX treatment, 0.38 +/- 0.06 g/m2; and on day 2 after the MTX infusion, 0.39 +/- 0.11 g/m2 (P < 0.01). A significant increase in proteinuria (> 0.2 g/m2 post- vs pretreatment) was detectable in 54% of the patients. In the period 1991-1992 we modified the hydration-alkalisation schedule to include i.v. prehydration for 18-24 h at 3 l/m2/day with a 0.45% NaCl-5% glucose solution along with sodium bicarbonate and posthydration for 72 h with the same solution. On this protocol the mean values determined for the urinary protein content were all in the normal range (pretreatment, 0.03 g/m2/day; day 1, 0.05 g/m2/day; and day 2, 0.08 g/m2/day). These findings were significantly different from the previous results (P < 0.05).


Assuntos
Metotrexato/efeitos adversos , Neoplasias/tratamento farmacológico , Proteinúria/induzido quimicamente , Adolescente , Neoplasias Ósseas/tratamento farmacológico , Linfoma de Burkitt/tratamento farmacológico , Criança , Feminino , Hidratação , Taxa de Filtração Glomerular/efeitos dos fármacos , Glucose/administração & dosagem , Humanos , Masculino , Metotrexato/administração & dosagem , Metotrexato/uso terapêutico , Osteossarcoma/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Proteinúria/prevenção & controle , Bicarbonato de Sódio/administração & dosagem
15.
Eur J Cancer ; 27(8): 1006-9, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1832883

RESUMO

The effect of folinic acid rescue dose on the event-free survival of 71 children with acute lymphoblastic leukaemia was examined in a retrospective clinical study. All patients, diagnosed between 1 January 1980 and 1 January 1989, were treated according to the Norwegian Pilot protocol which included eight courses of high dose (6-8 g/m2/24 h intravenous infusion) methotrexate. Following the infusion, a uniform dose of 75 mg (at 36 h after the beginning of the drug infusion) and 15 mg (at 39-106 h) folinic acid rescue was administered to all patients, at predetermined intervals. The uniformity of the rescue dose resulted in distribution of dosages in the range of 38-140 mg/m2 and 7.5-28 mg/m2 for the different periods, respectively, when the dose was recalculated on the basis of the body surface area of the individual patients. The event-free survival of children receiving less or more than 15 mg/m2 (75 mg/m2) rescue dose was compared. Although no significant difference was found, a tendency was observed for a lower risk of relapse in patients receiving less folinic acid. No major methotrexate-related toxicity was observed in the group of patients receiving the lower dose of rescue. These observations suggest that the reduction of folinic acid rescue dose below the generally accepted 12-15 mg/m2 dose may increase the efficacy of high-dose methotrexate therapy while still remaining safe in preventing treatment-related toxicity. Prospective, randomised clinical trials are needed to examine the role of rescue as a determinant of effective exposure to methotrexate in patients receiving high-dose methotrexate treatment.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Leucovorina/administração & dosagem , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Metotrexato/administração & dosagem , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Prognóstico , Recidiva , Estudos Retrospectivos , Fatores de Risco
16.
Med Pediatr Oncol ; 18(3): 217-24, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2329967

RESUMO

Concentrations of 7-hydroxy-methotrexate (7-OH-MTX) were determined in serum samples obtained after 266 infusions of methotrexate administered to 58 children with acute lymphoblastic leukemia. The dose of methotrexate (MTX) was in the range of 0.5-33.6 g/m2. Pharmacokinetic parameters (metabolic index, drug/metabolite ratio, half-life) of 7-OH-MTX and their relationship to the kinetics of methotrexate were analyzed. A great variability was observed in the extent and time-course of the metabolite formation. The concentration of the metabolite was higher than that of the parent compound at any examined time after the end of the 24 hours' infusion. The increase of 7-OH-MTX levels at the end of the methotrexate infusion was found to be proportionate to the increase of the dose of MTX. Males had significantly higher metabolite levels than did females (P less than 0.01) in the dose range of 0.5-8.0 g/m2. The age of the patients also significantly influenced the rate of the metabolite formation. The serial number of the treatment courses did not have effect on the metabolism of MTX. Dose dependency of the elimination half-life of the metabolite was found. Although a tendency was observed that patients in continuous complete remission had higher metabolite levels than those who relapsed, the difference was not significant. Further studies are needed to determine the clinical importance of 7-OH-MT.


Assuntos
Metotrexato/análogos & derivados , Metotrexato/administração & dosagem , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Adolescente , Fatores Etários , Criança , Pré-Escolar , Esquema de Medicação , Feminino , Meia-Vida , Humanos , Lactente , Cinética , Masculino , Metotrexato/sangue , Metotrexato/metabolismo , Indução de Remissão , Fatores Sexuais
17.
Cancer Chemother Pharmacol ; 27(2): 164-7, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2249335

RESUMO

Concentrations of methotrexate (MTX) and 7-hydroxymethotrexate (7-OH-MTX) were determined by HPLC in the serum and cerebrospinal fluid (CSF) of 29 children with acute lymphoblastic leukemia. CSF and serum samples were obtained at the end of 104 infusions of MTX given in a dose range of 0.5-8.0 g/m2. Concentrations, distribution ratios in serum and CSF for MTX and 7-OH-MTX, and the metabolic index were analyzed with regard to the MTX dose, age and clinical state of the patients. A wide inter-patient (2- to 12-fold) but narrower (1.1- to 3.5-fold) intra-patient variability of the concentrations was observed. A dose-proportional increase in the metabolite concentration was found in serum. On the other hand, the elevation of the level of metabolite in CSF was less than proportional to the dose. The CSF/serum distribution data suggest the existence of a saturable carrier system for MTX and 7-OH-MTX between serum and CSF that has lower affinity for 7-OH-MTX. No correlation was found between concentrations of MTX and 7-OH-MTX in the serum of patients receiving the same dose of MTX. No significant difference was observed in the values for metabolic index between relapsed patients and those who were in continuous complete remission. A significant correlation was found between age and metabolic index: the younger the patient, the higher the metabolite concentration measured in serum.


Assuntos
Antagonistas do Ácido Fólico/sangue , Metotrexato/análogos & derivados , Metotrexato/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Envelhecimento/metabolismo , Antineoplásicos/uso terapêutico , Criança , Pré-Escolar , Antagonistas do Ácido Fólico/líquido cefalorraquidiano , Humanos , Lactente , Infusões Intravenosas , Metotrexato/sangue , Metotrexato/líquido cefalorraquidiano , Metotrexato/metabolismo , Metotrexato/farmacocinética , Leucemia-Linfoma Linfoblástico de Células Precursoras/sangue , Leucemia-Linfoma Linfoblástico de Células Precursoras/líquido cefalorraquidiano , Prognóstico
18.
Pediatr Hematol Oncol ; 7(4): 347-63, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2268535

RESUMO

Pharmacologic rescue methods used in combination with intermediate and high-dose methotrexate therapy are reviewed, with special emphasis on rescue with nucleosides and folinic acid. The mechanism of action, pharmacokinetics, and clinical applications of the rescue agents are described in detail in view of the literature and also of the own findings of the authors. In spite of the promising results of the in vitro studies and in vivo experiments in animal models, the clinical value of thymidine as a rescue agent remains to be determined. Currently, the only indication to use thymidine instead of folinic acid following high-dose methotrexate is to prevent toxicity related to extremely high methotrexate levels in patients with delayed elimination of methotrexate. In spite of the widespread application of folinic acid rescue, the exact mechanism of its action is not fully understood. The rescue dose and schedule in the majority of clinical protocols is empirical, and the start of the rescue administration is too early, allowing less than 36 to 42 hours of exposure to methotrexate. Clinical and laboratory findings indicate that while the early start of FA administration is unnecessary for protecting normal cells, it is potentially dangerous in terms of reduction of the antitumor effect of methotrexate. Our findings suggest that less than the most widely used 12-15 mg/m2 per dose rescue may be sufficient in preventing methotrexate related toxicity in patients with normal elimination of the drug. In addition, reducing the dose of the rescue may be beneficial to achieve better therapeutic results with high-dose methotrexate. Due to methodological problems, the pharmacokinetics of folinic acid rescue has not been excessively studied in humans. Recent data indicate that the pharmacokinetics of folinic acid in children is characterized by great intra- and interpatient variability. The effect of food on the bioavailability of folinic acid has not yet been studied, though it is most frequently administered orally. The introduction of the pure l-stereoisomer of the rescue agent in the clinical practice may eliminate potential interactions with the d-isomer, and may also simplify the introduction of therapeutic drug monitoring for folinic acid as well. This could lead to more rational clinical use of folinic acid as a rescue agent following intermediate and high-dose methotrexate therapy.


Assuntos
Metotrexato/administração & dosagem , Metotrexato/efeitos adversos , Sobrevivência Celular/efeitos dos fármacos , Quimioterapia Combinada , Humanos , Leucovorina/farmacocinética , Leucovorina/uso terapêutico , Metotrexato/antagonistas & inibidores , Nucleosídeos/farmacocinética , Nucleosídeos/uso terapêutico , Tetra-Hidrofolatos/uso terapêutico
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