Analiza topiramata in njegovih presnovkov s tekočinsko kromatografijo sklopljeno z masno spektrometrijo v plazemskih vzorcih bolnikov z epilepsijo : Industrijska farmacija

Kitić, Milena (author), Roškar, Robert (mentor)

Topiramat (TPM) je protiepileptična učinkovina 2. generacije, namenjena za zdravljenje epilepsije samostojno ali v kombinaciji z drugimi zdravili. Uporablja se tudi za zdravljenje migrene pri odraslih ter napadih povezanih z Lennox – Gastautovim sindrom pri otrocih. Presnova TPM, kljub njegovi pogosti uporabi, še ni čisto razjasnjena. V ta namen je bila predhodno razvita zelo občutljiva (meja določitve presnovkov do 0,001 mg/L) in validirana analizna metoda na sistemu LC-MS/MS. Ta metoda nam je omogočila analizo realnih plazemskih vzorcev 66 bolnikov na rednem zdravljenju epilepsije s TPM ter ovrednotenje koncentracij TPM in njegovih petih presnovkov. Metodo smo pred izvedbo analiz preverili z ustreznimi vzorci ter jo prilagodili in nadgradili. Osrednji namen magistrske naloge je bil potrditi hipotezo smotrnosti oziroma predstaviti pomembnost terapevtskega spremljanja koncentracije zdravilne učinkovine TPM, pri čemer smo ovrednotiti vpliv časa vzorčenja, vpliv dnevnega odmerka TPM in vpliv soterapije s karbamazepinom (CBZ) na plazemske koncentracije TPM in njegovih presnovkov. Iz izmerjenih koncentracij plazemskih vzorcev v ravnotežnem stanju je razvidno, da gre za veliko variabilnost v koncentraciji TPM in njegovih presnovkov pri bolnikih, ki so prejemali dnevne odmerke TPM od 50 do 1200 mg. Čeprav je viden trend med višjimi dnevnimi odmerki TPM in višjo koncentracijo analitov, je korelacija dokaj slaba. Tudi pri primerjavi bolnikov, ki so prejemali enak dnevni odmerek, je variabilnost precejšna, saj so se izmerjene koncentracije analitov razlikovale tudi do 10-krat. Kljub temu odmerek TPM značilno vpliva na koncentracijo TPM in njegove presnovke, čas odvzema pa značilno vpliva le na plazemsko koncentracijo TPM. TPM se v največji meri presnovi v 2,3-desizopropiliden TPM (100-krat višja koncentracija kot ostali), sledijo pa 10-hidroksi TPM ter ostali trije presnovki (v istem velikostnem razredu). Pri souporabi višjih odmerkov CBZ (800-1600 mg/dan) je bilo ugotovljeno, da soterapija značilno vpliva na plazemsko koncentracijo TPM, saj se s povečevanjem odmerka CBZ koncentracija TPM znižuje. Višji odmerki CBZ tudi značilno povišajo normirano vrednost dveh presnovkov, pri čemer je vpliv izrazitejši pri presnovku 2,3-desizopropiliden TPM. Na osnovi zbranih in ovrednotenih podatkov lahko potrdimo hipotezo, da je terapevtsko spremljanje koncentracije TPM potrebno za varno in učinkovito zdravljenje epilepsije.

• Language: Slovenian
• Keywords: topiramat presnovki LC-MS/MS plazma spremljanje koncentracije učinkovin
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FFA - Faculty of Pharmacy
• Place of publishing: Ljubljana
• Publisher: [M. Kitić]
• Year: 2018
• Number of pages: VI, 47 f.
• PID: 20.500.12556/RUL-120257
• UDC: 616.853:615(043.3)
• COBISS.SI-ID: 4476785
• Publication date in RUL: 17.09.2020

Secondary language

• Language: English
• Title: Analysis of topiramat and its metabolites by liquid cromatography coupeld with mass spectromwetry in plasma samples of patients with epilepsy

Abstract

Topiramate (TPM) is a second-generation antiepileptic drug designed to treat epilepsy that can be prescribe alone or in combination with other medications. It is also used to treat migraine in adults and seizures associated with Lennox-Gastaut syndrome in children. Despite its frequent use, the metabolism of TPM has not yet been fully elucidated. To this end, a very sensitive and validated LC-MS/MS analytical method (quantification of metabolites down to 0.001 mg/L) was previously developed. This method enabled us to analyse the real plasma samples from 66 patients undergoing regular treatment for epilepsy with TPM and to evaluate the concentrations of TPM and its five metabolites. Before the analysis was carried out, the method was tested and adjusted and upgraded accordingly. The main purpose of the Master's thesis was to evaluate the importance of therapeutic monitoring of TPM. This required evaluating the effect of the sampling time, the effect of the daily dose of TPM and the effect of combined therapy with carbamazepine (CBZ) on plasma concentrations of TPM and its metabolites. The measured plasma sample concentrations in the steady state showed that there is a high variability in the concentration of TPM and its metabolites in patients receiving daily doses of TPM from 50 to 1200 mg. Although a trend can be observed between higher daily doses of TPM and a higher concentration of analytes, the correlation is rather poor. Similarly, when comparing patients who receive the same daily dose, the variability was significant, as the measured concentrations of the analytes varied up to 10-fold. Nevertheless, the dose of TPM has a significant effect on the concentration of TPM and its metabolites, while the sampling time only has a significant effect on plasma TPM concentration. TPM is mostly metabolized to 2,3-desizopropylidene TPM (ca. 100-fold higher concentration compared to other metabolites), followed by 10-hydroxy TPM and the other three metabolites (in the same size class). As for the use of TPM in conjunction with higher doses of CBZ (800-1600 mg/day), combined therapy has proven to have a significant effect on plasma TPM concentration, as the concentration of TPM decreases with the increase in the CBZ dose. Higher doses of CBZ also significantly increase the standardize value of two metabolites, with the effect being more pronounced for 2,3-desizopropylidene TPM. Based on the data collected and evaluated, we can confirm the hypothesis that therapeutic monitoring of TPM is essential for the safe and effective treatment of epilepsy.

• Keywords: TDM topiramate metabolites epilepsy LC-MS/MS plasma