Farmakokinetika metotreksata kod dece / Pharmacokinetics of Methotrexate in Children

Description

<p>Metotreksat kao antagonista folne kiseline ima &scaron;iroku upotrebu za lečenje brojnih maligniteta, primenjen u visokim dozama i u&nbsp; kombinciji&nbsp; sa leukovorinom. Iako&nbsp; je&nbsp; terapija&nbsp; visokim&nbsp; dozama&nbsp; metotreksata drastično pobolj&scaron;ala&nbsp; prognozu pacijenata sa malignitetom, te&scaron;ki neželjeni efekti terapije predstavljaju stalan klinički problem. Ciljevi istraživanja bili su određivanje serumske koncentracije metotreksata i izračunavanje farmakokinetičkih&nbsp; parametara&nbsp; metotreksata kod dece obolele od malignih&nbsp; bolesti&nbsp; koja su na terapiji visokim dozama metotreksata (2&nbsp; g/m² i&nbsp; 5&nbsp; g/m² ); ispitivanje postojanja uticaja primenjene doze metotreksata, demografskih i kliničkih karakteristika ispitanika&nbsp; na koncentracije i farmakokinetičke parametare. Ispitivano je prisustvo i stepen kliničkih i laboratorijskih znakova toksičnosti metotreksata, kao i uticaj primenjene&nbsp; doze&nbsp; metotreksata&nbsp; i demografskih karakteristika ispitanika&nbsp; na pojavu i stepen toksičnosti . U okviru retrospektivno - prospektivne&nbsp; studije&nbsp; ukjučeno&nbsp; je&nbsp; četrdeset&nbsp; i dva pedijatrijska&nbsp; pacijenta&nbsp; uzrasta od&nbsp; 0,75 do 17,75 godina (medijana 5,75&nbsp; godina). Svi pacijenti&nbsp; su lečeni&nbsp; u&nbsp; Službi&nbsp; za&nbsp; hematologiju i&nbsp; onkologiju&nbsp; Instituta&nbsp; za&nbsp; zdravstvenu za&scaron;titu dece i omladine Vojvodine (Novi Sad, Srbija) u periodu od juna 2004. godine do juna 2012. godine. Trideset i osam ispitanika&nbsp; je lečeno pod dijagnozom akutne limfoblastne leukemije&nbsp; prema dva&nbsp; uzastopna&nbsp; protokola ALL IC - BFM 2002 i ALL IC - BFM 2009 Internacionalne&nbsp; BFM studijske&nbsp; grupe &bdquo;I - BFM - SG&ldquo;&nbsp; (International Berlin -Frankfurt - M&uuml;nster Study Group) za proučavanje i lečenje dečje non-B akutne limfoblastne leukemije. Četvoro je&nbsp; imalo&nbsp; dijagnozu non - Hodgkin limfoma&nbsp; i bili su uključen i u&nbsp; protokol NHL - BFM&nbsp; 95. Istraživanje je obuhvatilo 113 ciklusa terapije metotreksatom (1&ndash; 4 ciklusa po pacijentu) sa 386 izmerenih serumskih koncentracija metotreksata. Raspon primenjenih doza metotreksata kretao se od 800 do 10.000 mg. Koncentracije metotreksata su merene 24, 36 i 42 sata nakon započinjanja infuzije metotreksata, a po potrebi i u dužim vremenskim intervalima. Za izračunavanje farmakokinetičkih parametara kori&scaron;ćen je dvokompartmanskih farmakokinetički&nbsp; model posle obustavljanja&nbsp; intravenske&nbsp; infuzije,&nbsp; gde&nbsp; postoje relacije&nbsp; za&nbsp; farmakokinetičke&nbsp; tačke. Podaci o kliničkim i laboratorijskim znacima toksičnosti metotreksata prikupljani su iz medicinske dokumentacije, a za stepenovanje toksičnosti kori&scaron;ćen je skor sistem - Common Terminology Criteria for&nbsp; Adverse&nbsp; Events (CTCAE), Version 4.0, U.S. Department&nbsp; of&nbsp; health&nbsp; and&nbsp; human services, National Institute of Health, National Cancer Institute. U cilju utvrđivanju uticaja karakteristika ispitanika, primenjene doze i prisustva produžene eliminacije na posmatrane parametre, vr&scaron;eno je poređenje tri grupe&nbsp; pacijenata (doza 2 g/m² bez produžene eliminacije, 5 g/m² bez produžene liminacije i 5 g/m² sa produženom eliminacijom metotreksata). Za celokupnu grupu ispitanika,&nbsp; medijane&nbsp; koncentracije metotreksta&nbsp; bile&nbsp; su 25,82 &mu;mol/l u 24. satu, 0,68 &mu;mol/l u 36. satu i 0,24 &mu;mol/l u 42. satu merenja. Najizraženija interindividualna varijabilnost u koncentracijama metotreksata bila je u 42. satu merenja, dok je&nbsp; intraindividualna varijabilnost bila najizraženija u 36. satu merenja. Medijana&nbsp; klirensa&nbsp;&nbsp; metotreksata&nbsp;&nbsp; bila&nbsp; je 8,32&nbsp;&nbsp; l/h. Farmakokinetički parametri&nbsp; redom bili su:&nbsp; medijana&nbsp; volumena&nbsp; centralnog&nbsp; kompartmana V₁ 28,47&nbsp; l, medijane konstanti k₁₀ 0,206, k₁₂ 0,0245, k₂₁ 0,1114. Najizraženiji uticaj primenjene doze na koncentracije metotreksata pokazan je u 24.&nbsp; satu&nbsp; merenja, dok uticaj doze na klirens&nbsp; metotreksata nije&nbsp; pokazan. Prisustvo produžene eliminacije metotreksata dovodi do smanjenih vrednosti konstanta k₁₀ i k₂₁. Nije pokazana statistički značajna&nbsp; interakcija ispitivanih demografskih karakteristika (uzrast, telesna povr&scaron;ina i pol)&nbsp; i koncentracija metotreksata, kao ni klirensa metotreksata. Pokazana je značajna interakcija između koncentracija metotreksata i nivoa laktat dehidrogenaze, kao i klirensa metotreksata i nivoa kreatinina i laktat dehidrogenaze. Većina ispoljenih&nbsp; toksičnosti bila je umerenog stepena (&lt;3 stepena). Najzastupljeniji klinički znak toksičnosti bio je oralni mukozitis, koji je bio većeg stepena u grupi sa većom primenjenom dozom metotreksata&nbsp; (5g/m²). Najzastupljeniji&nbsp; laboratorijski toksični efekti&nbsp; metotreksata bili su leukopenija i anemija. Najteži stepeni laboratorijskih znakova toksičnosti (leukopenija, anemija, porast&nbsp; AST,&nbsp; ALT i GGT) nalazili su se u grupi sa većom dozom&nbsp; (5 g/m²) i&nbsp; sa produženom eliminacijom metotreksata. Osnov&nbsp; za&nbsp; kliničko&nbsp; vođenje&nbsp; pacijenata&nbsp; na&nbsp; terapiji visokim dozama metotreksata je terapijsko praćenje leka (therapeutic drug monitoring &ndash; TDM) zbog velikih&nbsp; interindividualnih i intraindividualnih&nbsp; varijabilnosti&nbsp; u&nbsp; farmakokinetici&nbsp; leka. Rutinsko praćenje koncentracija metotreksata važno je za identifikaciju pacijenata sa povećanim rizikom od razvoja toksičnosti ,&nbsp; te&nbsp; je TDM&nbsp; standardna&nbsp; praksa&nbsp; za smernice spasavanja leukovorinom, naročito za pacijente za koje se zna da imaju smanjen&nbsp;&nbsp; klirens metotreksata ili druge rizike povezane sa prolongiranim citotoksičnim koncentracijama (bubrežna ili jetrena o&scaron;tećenja, kolekcije tečnosti u &ldquo;trećem prostoru&rdquo;, gastrointestinalna opstrukcija). Veliki&nbsp; broj&nbsp; istraživanja&nbsp; kod pedijatrijskih pacijenata pokazao je vezu između sistemskog izlaganja metotreksatu i&nbsp; efikasnosti&nbsp; i&nbsp; toksiĉnosti&nbsp; metotreksata. Ipak, ne postoji dovoljno&nbsp; informacija o farmakokinetici metotreksata kod dece obolele od akutne limfoblastne leukemije. Takođe, ova istraživanja nisu do sada sprovođena kod dece koja su lečena u na&scaron;oj sredini.</p> / <p>Methotrexate&nbsp; is&nbsp; an&nbsp; antifolate&nbsp; drug&nbsp; widely&nbsp; used&nbsp; for&nbsp; treatment&nbsp; of&nbsp; various malignant&nbsp; tumours.&nbsp; It&nbsp; is&nbsp; used&nbsp; at&nbsp; high&nbsp; doses&nbsp; and&nbsp; in&nbsp; combination&nbsp; with leucovorin rescue.&nbsp; Although&nbsp; high - dose&nbsp; MTX&nbsp; therapy&nbsp; dramatically&nbsp; improves&nbsp; the&nbsp; prognosis&nbsp; of patients with malignancies, severe adverse events are constant clinical concern. The&nbsp; aims&nbsp; of&nbsp; this&nbsp; stydy&nbsp; were&nbsp; to&nbsp; determine&nbsp; the&nbsp; serum&nbsp; concentration&nbsp; of&nbsp; methotrexate&nbsp; and&nbsp; to&nbsp; calculate&nbsp; the&nbsp; pharmacokinetic&nbsp; parameters&nbsp; of&nbsp; methotrexate&nbsp; in children&nbsp; suffering&nbsp; from&nbsp; malignant&nbsp; deseases&nbsp; who&nbsp; are&nbsp; treated&nbsp; with&nbsp; high&nbsp; doses&nbsp; of metotrexate&nbsp; (2&nbsp; g/m² i&nbsp; 5&nbsp; g/m² );&nbsp; furthermore,&nbsp; to&nbsp; investigate&nbsp; the&nbsp; effects&nbsp; of&nbsp; the&nbsp; applied doses of methotrexate, and demographic and clinical characteristics of the examinees on&nbsp;&nbsp; the&nbsp;&nbsp; concentration&nbsp;&nbsp; and&nbsp;&nbsp; pharmacokinetic&nbsp;&nbsp; parameters&nbsp;&nbsp; of&nbsp;&nbsp; the&nbsp;&nbsp; drug.&nbsp;&nbsp; The&nbsp;&nbsp; study investigated the&nbsp;&nbsp; presence&nbsp;&nbsp; and&nbsp;&nbsp; the&nbsp;&nbsp; degree&nbsp;&nbsp; of&nbsp;&nbsp; clinical&nbsp;&nbsp; and&nbsp;&nbsp; laboratory&nbsp;&nbsp; signs&nbsp;&nbsp; of metotrexate&nbsp; toxicity,&nbsp; as&nbsp; well&nbsp; as&nbsp; the&nbsp; effect&nbsp; of&nbsp; the&nbsp; applied&nbsp; doses,&nbsp; and&nbsp; demographic characteristics of the examinees on the appearance and the degree of toxicity. The retrospective - prospective study included 42&nbsp; pediatric patients aged from 0.75&nbsp; to&nbsp; 17.75&nbsp; years&nbsp; (median&nbsp; 5.75&nbsp; years).&nbsp; All&nbsp; patients&nbsp; were&nbsp; threated&nbsp; at&nbsp; the&nbsp; Children and Youth Health Care Institute of Vojvodina (Novi Sad, Serbia), Hemathology and Oncology&nbsp; Section,&nbsp; in&nbsp; the&nbsp; period&nbsp; from&nbsp; June&nbsp; 20 04&nbsp; to&nbsp; June&nbsp; 2012.&nbsp; 38&nbsp; examinees diagnosed as acute lymphoblastic leukemia were treated according to two subsequent protocols,&nbsp; ALL&nbsp; IC - BFM&nbsp; 2002&nbsp; and&nbsp; ALL&nbsp; IC - BFM&nbsp; 2009&nbsp; of&nbsp; the&nbsp; International&nbsp; BFM study&nbsp; group &bdquo;I - BFM - SG&ldquo; (International Berlin - Frankfurt - M&uuml;nster&nbsp; Study&nbsp; Group)&nbsp; for management&nbsp;&nbsp; of&nbsp;&nbsp; childhood&nbsp;&nbsp; non - B&nbsp;&nbsp; acute&nbsp;&nbsp; lymphoblastic&nbsp;&nbsp; leukemia.&nbsp;&nbsp; 4&nbsp;&nbsp; examinees diagnosed&nbsp; as&nbsp; non - Hodgkin&nbsp; lymphoma&nbsp; were&nbsp; treated&nbsp; according&nbsp; to&nbsp; the&nbsp; NHL - BFM&nbsp; 95 protocol. The study included 113 cycles of therapy with methotrexate (1-4 cycles per patient)&nbsp; with&nbsp; 3 86&nbsp; measured&nbsp; serum&nbsp; concentrations&nbsp; of&nbsp; methotrexate.&nbsp; The&nbsp; range&nbsp; of&nbsp; the applied doses was between 800 and 10,000 mg. The&nbsp; concentration&nbsp; of&nbsp; methotrexate&nbsp; was&nbsp; measured&nbsp; 24,&nbsp; 36&nbsp; and&nbsp; 42&nbsp; hours&nbsp; after the initiation of the methotrexate infusion, as well as in longer time intervals when needed.&nbsp; To&nbsp; calculate&nbsp; the&nbsp; pharmacokinetic&nbsp; parameters,&nbsp; the&nbsp; study&nbsp; applied&nbsp; the&nbsp; two - compartment&nbsp; pharmacokinetic&nbsp; model&nbsp; after&nbsp; the&nbsp; termination&nbsp; of&nbsp; intravenous&nbsp; infusion, when&nbsp; relations&nbsp; for&nbsp; pharmacokinetic&nbsp; points&nbsp; existed.&nbsp; Data&nbsp; on&nbsp; clinical&nbsp; and&nbsp; laboratory signs of methotrexate toxicity were collected&nbsp; from medical documentation, and the Common&nbsp; Terminology&nbsp; Criteria&nbsp; for&nbsp; Adverse&nbsp; Events&nbsp; (CTCAE),&nbsp; Version&nbsp; 4.0,&nbsp; U.S. Department&nbsp; of&nbsp; health&nbsp; and&nbsp; human&nbsp; services,&nbsp; National&nbsp; Institute&nbsp; of&nbsp; Health,&nbsp; National Cancer&nbsp; Institute, was&nbsp; used&nbsp; as&nbsp; the&nbsp; score&nbsp; system&nbsp; for&nbsp; toxicity&nbsp; ranking.&nbsp; In&nbsp; order&nbsp; to determine&nbsp; the&nbsp; effects&nbsp; of&nbsp; the examinees&rsquo;&nbsp; characteristics, applied&nbsp; doses&nbsp; and&nbsp; the presence&nbsp; of&nbsp; prolonged&nbsp; elimination on&nbsp; the&nbsp; parameters&nbsp; of&nbsp; interest,&nbsp; three&nbsp; groups&nbsp; of patients were&nbsp; compared (2 g/m² dose without prolonged elimination, 5 g/m² without prolonged elimination and 5 g/m² with prolonged elimination of methotrexate). In the&nbsp; entire&nbsp; group of&nbsp; examinees, the median&nbsp; concentration of methotrexate was&nbsp; 25.82 &mu;mol/l in the 24th hour, 0.68 &mu;mol/l in the 36th&nbsp; hour&nbsp; and 0.24 &mu;mol/l in the 42nd hour of&nbsp; observation. The largest inter - individual variability of methotrexate concentration&nbsp; was&nbsp; observed&nbsp; in&nbsp; the&nbsp; 24th&nbsp; hour&nbsp; while&nbsp; the&nbsp; largest&nbsp; intra - individual variability&nbsp; was&nbsp; recorded&nbsp; in&nbsp; the&nbsp; 36th&nbsp; hour&nbsp; of&nbsp; observation.&nbsp; The&nbsp; median&nbsp; clearance&nbsp; of methotrexate&nbsp; was&nbsp; 8.32l/h.&nbsp; Pharmacokinetic&nbsp; parameters&nbsp; were&nbsp; the&nbsp; following:&nbsp; median volume&nbsp; of&nbsp; the&nbsp; central&nbsp; compartment V₁ 28.47&nbsp; l,&nbsp; median&nbsp; constants k₁₀ 0,206, k₁₂ 0,0245, k₂₁ 0,1114, respectively. The&nbsp;&nbsp; strongest&nbsp;&nbsp; influence&nbsp;&nbsp; of&nbsp;&nbsp; the&nbsp;&nbsp; applied&nbsp;&nbsp; dose&nbsp;&nbsp; on&nbsp;&nbsp; the&nbsp;&nbsp; methotrexate concentration was recorded in the 24th hour of observation while no influence on the methotrexate&nbsp; clearance&nbsp; was&nbsp; found.&nbsp; The&nbsp; presence&nbsp; of&nbsp; prolonged&nbsp; elimination&nbsp; of methotrexate&nbsp;&nbsp; causes&nbsp;&nbsp; lower&nbsp; constants k₁₀ and&nbsp;&nbsp; k₂₁. There&nbsp;&nbsp; was&nbsp;&nbsp; no&nbsp;&nbsp; statistically significant&nbsp; interaction&nbsp; between&nbsp; the&nbsp; investigated&nbsp; demographic&nbsp; characteristics&nbsp; (age, body&nbsp; surface&nbsp; and&nbsp; gender)&nbsp; and&nbsp; the&nbsp; methotrexate&nbsp; concentration,&nbsp; nor&nbsp; between&nbsp; the demographic&nbsp;&nbsp; characteristics&nbsp;&nbsp; and&nbsp;&nbsp; the&nbsp;&nbsp; methotrexate&nbsp;&nbsp; clearance.&nbsp;&nbsp; A&nbsp;&nbsp; significant interaction was found between methotrexate concentration and lactat dehydrogenase level, as&nbsp;&nbsp; well&nbsp;&nbsp; as&nbsp;&nbsp; between&nbsp;&nbsp; methotrexate&nbsp;&nbsp; clearance&nbsp;&nbsp; and&nbsp;&nbsp; creatinine&nbsp;&nbsp; and&nbsp;&nbsp; lactate dehydrogenase level, respectively. Most of the observed toxicities were of moderate degree (&lt; 3 degrees). Oral mucositis&nbsp; was&nbsp; the&nbsp; most&nbsp; represented&nbsp; clinical&nbsp; sign&nbsp; of&nbsp; toxicity,&nbsp; and&nbsp; it&nbsp; was&nbsp; of&nbsp; higher degree&nbsp; in&nbsp; the&nbsp; group&nbsp; where&nbsp; the&nbsp; applied&nbsp; dose&nbsp; of&nbsp; methotrexate&nbsp; was&nbsp; higher&nbsp; (5&nbsp; g/m² ). Leucopenia&nbsp; and&nbsp; anemia&nbsp; were&nbsp; the&nbsp; most&nbsp; represented&nbsp; laboratory&nbsp; toxic&nbsp; effects.&nbsp; The most severe laboratory signs of toxicity&nbsp; (leucopenia, anemia, increase in AST, ALT and&nbsp; GGT&nbsp; activity)&nbsp; were&nbsp; observed&nbsp; in&nbsp; the&nbsp; group&nbsp; with&nbsp; the&nbsp; higher&nbsp; dose&nbsp; (5&nbsp; g/m² )&nbsp; and prolonged methotrexate elimination. Due to high inter- and&nbsp;&nbsp; intra-individual&nbsp;&nbsp;&nbsp; variability&nbsp; of&nbsp; the drug pharmacokinetics,&nbsp; the&nbsp; basis&nbsp; for&nbsp; the&nbsp; clinical&nbsp; care&nbsp; of&nbsp; patients&nbsp; on&nbsp; high&nbsp; methotrexate dosage&nbsp; therapy&nbsp; is&nbsp; therapeutic&nbsp; drug&nbsp; monitoring &ndash; TDM.&nbsp; Routine&nbsp; monitoring&nbsp; of methotrexate serum concentration is important for the identification of patients with a high&nbsp; risk&nbsp; of&nbsp; toxicity,&nbsp; and&nbsp; thus&nbsp; TDM&nbsp; is&nbsp; used&nbsp; as&nbsp; a&nbsp; standard&nbsp; procedure&nbsp; which&nbsp; provides guidelines&nbsp; for&nbsp; leucovorin&nbsp; rescue,&nbsp; particularly&nbsp; for&nbsp; patients&nbsp; with&nbsp; a&nbsp; lower&nbsp; methotrexate clearance or other risks associated with prolonged cytotoxic concent rations (kidney or liver&nbsp; damage,&nbsp; body&nbsp; fluid&nbsp; accumulation&nbsp; in&nbsp; the&nbsp; &ldquo;third&nbsp; space&rdquo;,&nbsp; gastrointestinal obstruction). Numerous studies involving pediatric patients have documented the link between&nbsp; a&nbsp; systemic&nbsp; methotrexate&nbsp; exposure&nbsp; on&nbsp; one&nbsp; hand,&nbsp; and&nbsp; the&nbsp; efficiency&nbsp; and toxicity of&nbsp; ethotrexate on the other hand. However, there is no sufficient data on the methotrexate&nbsp;&nbsp;&nbsp; pharmacokinetics&nbsp;&nbsp; in&nbsp;&nbsp; children&nbsp;&nbsp; suffering&nbsp;&nbsp; from&nbsp;&nbsp; acute&nbsp;&nbsp; lymphoblastic leukemia.&nbsp;&nbsp; Moreover,&nbsp;&nbsp; this&nbsp;&nbsp; type&nbsp;&nbsp; of&nbsp;&nbsp; research,&nbsp;&nbsp; involving&nbsp;&nbsp; children&nbsp;&nbsp; treated&nbsp;&nbsp; in&nbsp;&nbsp; the geographical region of this study, have not been conducted.</p>

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1. https://www.cris.uns.ac.rs/DownloadFileServlet/Disertacija14395441025464.pdf?controlNumber=(BISIS)95484&fileName=14395441025464.pdf&id=4174&source=NDLTD&language=en
2. https://www.cris.uns.ac.rs/record.jsf?recordId=95484&source=NDLTD&language=en

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Identifer	oai:union.ndltd.org:uns.ac.rs/oai:CRISUNS:(BISIS)95484
Date	23 November 2015
Creators	Tošić Jela
Contributors	Popović Jovan, Kolarović Jovanka, Konstantinidis Nada, Urošević Ivana, Savić Aleksandar, Popović Mira, Katanić Dragan
Publisher	Univerzitet u Novom Sadu, Medicinski fakultet u Novom Sadu, University of Novi Sad, Faculty of Medicine at Novi Sad
Source Sets	University of Novi Sad
Language	Serbian
Detected Language	Unknown
Type	PhD thesis