Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Lucie Ungerová Supervisor: PharmDr. Jana Pourová, Ph.D. Title of diploma thesis: The pharmakokinetics of isoflavonoids The aim of this diploma thesis is to summarize currently available informations about the pharmacokinetics of the polyfenolic compounds from a large group of flavonoids, isoflavonoids. Isoflavonoids are coumpounds found in many plant families, but especially in some members of Fabaceae family. One of the main well-known sources are soy beans containing the most famous isoflavones - genistein and daidzein, their pharmakokinetics is the main theme of this diploma thesis. Since isoflavonoids are mainly contained in the diet, their oral administration is very relevant. Isoflanonoids in the human diet occurs predominantly in the form of glykosides and therefore, after ingestion, they have to be deglycosylated by β- glucosidase enzyme family to aglycones. After that they are able to pass through the intestine into the systemic circulation and they are available for action. This is already happening in the oral cavity and the absorption occurs in the small intestine. The intestinal bacterial microflora composition is also very important for pharmacokinetics, for example I can mention...

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Dominika Sobotová Tutor: PharmDr. Ivan Vokřál, Ph.D. Title of diploma thesis: Pharmacokinetics of ivermectin in the sheep feces Key words: ivermectin, pharmacokinetics, sheep, anthelminthic Infection with internal parasites (endoparasites) is one of the most common diseases in sheep. Infection with these parasites mainly with the barber's pole worm (Haemonchus contortus) causes considerable economic losses and has a significant impact on sheep productivity. Anthelmintics, including ivermectin, are used for treatment. Ivermectin belongs to the class of macrocyclic lactones and is characterised by broad spectrum and low toxicity. On the other hand, it poses a risk to the environment in form of residues that are excreted in feces by treated individuals. The aim of this study was to determine the excretion profile of ivermectin in sheep subcutaneously administered in a standard dose 0,2 mg/kg of body weight. UHPLC/MS/MS method was used for the analysis of ivermectin fecal concentration. Based on the obtained results we determined basic pharmacokinetic parameters which includes time to achieve maximum concentration (tmax), maximum concentration (cmax), area under the curve (AUC) and mean residence...

Background and Objectives: Tendencies in Drug Use (DU) of highly toxic drugs-such as aminoglycosides and vancomycin and level of Rational Drug Use (RDU) is unknown in Lithuania. Our goal was to evaluate the first experiences in serum concentration measurements (Sc) of vancomycin & gentamicin, monitor patients receiving these antimicrobials and explore the practicality of using defined daily dose (DDD) in measuring their consumption tendencies. Design: DU study based on hospital pharmacy and hospital administrative databases; consumption in DDD per 100 occupied bed daily (100OBD) during 2004-6 and highest consumers of aminoclycosides and vancomycin in 2006. Evaluation of Sc in 2006. Monitoring assessment of 17 patients over 7 months. Data were processed with SPSS 16.0 using descriptive and comparative statistics for nonparametric values (Mann-Whitney test). Main outcomes measures: Annual consumptions of gentamicin, amikacin, tobramycin and vancomycin according to DDD/100OBD; intensity of gentamicin & vancomycin monitoring (as per number of DDDs) and proportions of abnormal Sc; Evaluation of the rationality level of antimicrobial’s therapy in a cohort of 17 patients. Results: Mean (±SE) DDD/100OBD values of gentamicin (240mg) were 3.67±0.69 (median 1.31; CI95% 2.29-5.06) in 2004; 4.53±1.87 (median 0.86; CI 95% 0.79-8.27) in 2005, and 4.24±0.82 (median 1.05; CI95%2.60-5.88) in 2006. Mean (±SE) DDD/100OBD values of amikacin (1000mg) were 0.55±0.17 (median 1.22; CI95% 0.23-0... [to full text] / Toksiškų vaistų, tokių kaip aminoglikozidų ir vankomicino, bei racionalus vaistų vartojimo tendencijos Lietuvoje dar nėra pakankamai žinomos. Mūsų darbo tikslas buvo nustatyti ir įvertinti aminoglikozidų ir vankomicino suvartojimo KMU klinikose tendencijas , gentamicino ir vankomicino koncentracijas kraujo serume (KKS), bei įvertinti 17 stebėtų pacientų gydymo šiais antibiotikais atvejus. Vaistų suvartojimo duomenys buvo gauti iš ligoninės vaistinės ir jos administracijos. Apskaičiuotos DDD šimtui lovadienių per paskutinius trejus metus (2004 – 2006), nustatyti daugiausia 2006 metais aminoglikozidų ir vankomicino suvartoję KMU klinikų skyriai. Įvertintos 2006 m. antibiotikų KKS. 17 pacientų, gavę šiuos antibiotikus, buvo stebimi 7 mėnesius. Duomenų statistinė analizė buvo atlikta naudojant SPSS 16.0 statistinę duomenų apdorojimo programą, kokybinių duomenų įvertinimui atliktas Mann-Whitney testas neparametriniams kriterijams. Vidutinis gentamicino (240mg) suvartojimas 2004m. (±SE) DDD/100OBD buvo 3.67±0.69 (median 1.31; CI95% 2.29-5.06); 2005m. 4.53±1.87 (median 0.86; CI 95% 0.79-8.27); 2006m. 4.24±0.82 (median 1.05; CI95%2.60-5.88). Amikacino (1000mg) buvo 0.55±0.17 (median 1.22; CI95% 0.23-0.88) 2004m.; 2005m. 0.44±0.13 (median 1.03; CI 95% 0.18-0.69), ir 0.52±0.13 (median 1.08; CI95%0.27-0.78) 2006m. Tobramicino (240mg) buvo 0.03±0.02 (median 0.14; CI95% 0.00-0.07) 2004m, 0.006±0.003 (median 0.03; CI95% 0.00-0.01) 2005m. Vancomicino (2000mg) buvo 0.55±0.17... [toliau žr. visą tekstą]

Highly active antiretroviral therapy (HAART) has improved the life expectancy of HIV–1–infected patients dramatically since it was launched in 1996, but there are still many challenges in the provision of HAART, especially to children in resource limited countries. Efavirenz (EFV), a non–nucleoside reverse transcriptase inhibitor (NNRTI) forms part of the recommended national first line antiretroviral treatment regimen for children older than 3 years and weighing more than 10 kg in South Africa. Limited pharmacokinetic information on EFV plasma concentrations in sub–Saharan HIV–1– infected children is available. EFV is primarily metabolised by hepatic CYP2B6 isoenzymes. The CYP2B6 gene is characterised by extensive inter–individual variability in hepatic expression and activity. The single nucleotide change, 516G>T, on the CYP2B6 gene has consistently been associated with elevated EFV plasma levels in different ethnic populations and these are more frequently observed in populations of African descent. The recommended therapeutic range of EFV plasma levels is 1–4 ug/ml and the Cmin should be above 1 ug/ml. In this prospective study (PK/PD.EFV.07) cohort, 60 black children, both genders, with no prior exposure to antiretroviral therapy and eligible for antiretroviral therapy (ART) were enrolled and followed up at 1, 3, 6, 12, 18 and 24 months post HAART initiation. They all attended the outpatient clinic at Harriet Shezi Children’s Clinic, Chris Hani Baragwanath Hospital, Soweto, South Africa. The required ethics approval was obtained to conduct this study. The objectives of this investigation were to: develop and validate a suitable LCMS/ MS method to accurately determine plasma EFV levels from this study population, determine the prevalence and effect of CYP2B6 516G>T polymorphism on EFV plasma levels, determine the population pharmacokinetic clearance (CL/F) value of EFV, identify covariates that influence the clearance of EFV in HIV–1– infected children, and investigate specific pharmacodynamic effects and therapeutic outcomes of this EFV–based regimen within this paediatric population over the 24 months post–HAART initiation. The main findings of the measured mid–dose EFV plasma concentrations showed that sub–therapeutic concentrations (<1 ug/ml) accounted for 18% (116/649), within therapeutic range (1–4 ug/ml) represented 52.5% (341/649), and concentrations above the therapeutic range (>4 ug/ml) represented 29.5% (192/649). A significant number of the samples (47.5%) were outside the accepted therapeutic range during this 24 month follow–up period. Possible reasons contributing to this include genetic variation in drug metabolism and non–adherence. Genotype results on all 60 study participants were: 23% 516 T/T homozygotes, 42% 516 G/G homozygotes and 35% 516 G/T heterozygotes. The 516 T–allelic variant frequency was relatively high at 41%. This also supports and explains why such a large number (29.5%) of the mid–dose interval plasma samples were above (>4 ug/ml) the accepted therapeutic range. Repeated measures ANOVA confirmed that CYP2B6 516 G/G, G/T and T/T genotypes were consistently predictive of the log EFV concentrations at all times (P = 0.0001). The total median (IQR) EFV plasma concentrations over the 24 months post–HAART when pooled, were 6.36 (3.47 - 7.28) for T/T, 2.55 (1.62 - 3.59) for G/T, and 1.41 (1.02 - 1.74) ug/ml for G/G groups respectively (P<0.00001). Multiple comparisons by groups revealed that the EFV plasma concentrations between the T/T and G/G (P=0.000002) and between G/T and G/G (P=0.009) were statistically significant. However, the differences between the EFV plasma concentrations of the T/T and G/T groups were not significantly different (P=0.074). This supports previous results that the presence of the 516 T–allelic variant is responsible for the higher EFV plasma concentrations within individuals presenting with this single nucleotide mutation on the CYP2B6 gene. This EFV–based treatment was well tolerated even at plasma concentrations above the therapeutic range (>4 ug/ml) and most side effects subsided spontaneously. 89% of the participants were virally suppressed at 24 months post–HAART. The efficacy of this EFV–based treatment did not affect the three genotype groups differently and they showed similar improvement in their immunological (CD4–cell count and CD4%) markers and reduction in viral load over the 24 months post– HAART initiation. We found no association of the CYP2B6 516G>T polymorphism and side effects reported after 1 month of treatment within this study population. The final population pharmacokinetic (PK) estimates for EFV clearance (CL/F) were, 2.46, 4.60, and 7.33 l/h for the T/T, G/T, and G/G respective genotype groups. The volume of distribution (V/F) estimate was 89.52 l. The importance of interoccasion variability (IOV) in a PK model for a longitudinal study was again highlighted by this investigation. To our knowledge, this is the first study in black South African HIV–1–infected children with measured sequential EFV plasma concentrations which also investigated the influence of the CYP2B6 516G>T polymorphism on EFV plasma concentrations and the population clearance (CL/F) value of EFV in a longitudinal study over a period of 24 months post–HAART initiation. / Thesis (Ph.D. (Pharmacology))--North-West University, Potchefstroom Campus, 2011.

Highly active antiretroviral therapy (HAART) has improved the life expectancy of HIV–1–infected patients dramatically since it was launched in 1996, but there are still many challenges in the provision of HAART, especially to children in resource limited countries. Efavirenz (EFV), a non–nucleoside reverse transcriptase inhibitor (NNRTI) forms part of the recommended national first line antiretroviral treatment regimen for children older than 3 years and weighing more than 10 kg in South Africa. Limited pharmacokinetic information on EFV plasma concentrations in sub–Saharan HIV–1– infected children is available. EFV is primarily metabolised by hepatic CYP2B6 isoenzymes. The CYP2B6 gene is characterised by extensive inter–individual variability in hepatic expression and activity. The single nucleotide change, 516G>T, on the CYP2B6 gene has consistently been associated with elevated EFV plasma levels in different ethnic populations and these are more frequently observed in populations of African descent. The recommended therapeutic range of EFV plasma levels is 1–4 ug/ml and the Cmin should be above 1 ug/ml. In this prospective study (PK/PD.EFV.07) cohort, 60 black children, both genders, with no prior exposure to antiretroviral therapy and eligible for antiretroviral therapy (ART) were enrolled and followed up at 1, 3, 6, 12, 18 and 24 months post HAART initiation. They all attended the outpatient clinic at Harriet Shezi Children’s Clinic, Chris Hani Baragwanath Hospital, Soweto, South Africa. The required ethics approval was obtained to conduct this study. The objectives of this investigation were to: develop and validate a suitable LCMS/ MS method to accurately determine plasma EFV levels from this study population, determine the prevalence and effect of CYP2B6 516G>T polymorphism on EFV plasma levels, determine the population pharmacokinetic clearance (CL/F) value of EFV, identify covariates that influence the clearance of EFV in HIV–1– infected children, and investigate specific pharmacodynamic effects and therapeutic outcomes of this EFV–based regimen within this paediatric population over the 24 months post–HAART initiation. The main findings of the measured mid–dose EFV plasma concentrations showed that sub–therapeutic concentrations (<1 ug/ml) accounted for 18% (116/649), within therapeutic range (1–4 ug/ml) represented 52.5% (341/649), and concentrations above the therapeutic range (>4 ug/ml) represented 29.5% (192/649). A significant number of the samples (47.5%) were outside the accepted therapeutic range during this 24 month follow–up period. Possible reasons contributing to this include genetic variation in drug metabolism and non–adherence. Genotype results on all 60 study participants were: 23% 516 T/T homozygotes, 42% 516 G/G homozygotes and 35% 516 G/T heterozygotes. The 516 T–allelic variant frequency was relatively high at 41%. This also supports and explains why such a large number (29.5%) of the mid–dose interval plasma samples were above (>4 ug/ml) the accepted therapeutic range. Repeated measures ANOVA confirmed that CYP2B6 516 G/G, G/T and T/T genotypes were consistently predictive of the log EFV concentrations at all times (P = 0.0001). The total median (IQR) EFV plasma concentrations over the 24 months post–HAART when pooled, were 6.36 (3.47 - 7.28) for T/T, 2.55 (1.62 - 3.59) for G/T, and 1.41 (1.02 - 1.74) ug/ml for G/G groups respectively (P<0.00001). Multiple comparisons by groups revealed that the EFV plasma concentrations between the T/T and G/G (P=0.000002) and between G/T and G/G (P=0.009) were statistically significant. However, the differences between the EFV plasma concentrations of the T/T and G/T groups were not significantly different (P=0.074). This supports previous results that the presence of the 516 T–allelic variant is responsible for the higher EFV plasma concentrations within individuals presenting with this single nucleotide mutation on the CYP2B6 gene. This EFV–based treatment was well tolerated even at plasma concentrations above the therapeutic range (>4 ug/ml) and most side effects subsided spontaneously. 89% of the participants were virally suppressed at 24 months post–HAART. The efficacy of this EFV–based treatment did not affect the three genotype groups differently and they showed similar improvement in their immunological (CD4–cell count and CD4%) markers and reduction in viral load over the 24 months post– HAART initiation. We found no association of the CYP2B6 516G>T polymorphism and side effects reported after 1 month of treatment within this study population. The final population pharmacokinetic (PK) estimates for EFV clearance (CL/F) were, 2.46, 4.60, and 7.33 l/h for the T/T, G/T, and G/G respective genotype groups. The volume of distribution (V/F) estimate was 89.52 l. The importance of interoccasion variability (IOV) in a PK model for a longitudinal study was again highlighted by this investigation. To our knowledge, this is the first study in black South African HIV–1–infected children with measured sequential EFV plasma concentrations which also investigated the influence of the CYP2B6 516G>T polymorphism on EFV plasma concentrations and the population clearance (CL/F) value of EFV in a longitudinal study over a period of 24 months post–HAART initiation. / Thesis (Ph.D. (Pharmacology))--North-West University, Potchefstroom Campus, 2011.

Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Mgr. Ondřej Martinec Supervisor: Assoc. Prof. PharmDr. Lukáš Červený, Ph.D. Title of doctoral thesis: Interactions of antiretroviral drugs with membrane transporters Oral delivery is the most common, convenient, and economical form of drug administration. Absorption of orally administered drugs occurs mainly in the intestine. Intestinal absorption can be reduced by the activity of efflux drug ABC transporters, mainly p-glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2), located in the apical membrane of the intestinal epithelium. HIV-infected patients are dependent on lifelong pharmacotherapy, which includes a combination of three or more antiretroviral drugs. Hepatitis C (HCV) is a common co-infection of HIV. In addition, the HIV-positive population is aging, which is associated with burden of other comorbidities. This results in an indication of polypharmacy and thus an increased risk of drug-drug interactions. Many antiretroviral drugs used are substrates, inhibitors and /or inducers of ABCB1, so they might quantitatively affect the intestinal absorption of co-administered drugs (ABCB1 substrates), thereby affecting the efficacy/safety of treatment. As part of this...

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Dominika Sobolová Supervisor: Assoc. Prof. Přemysl Mladěnka, Pharm.D., Ph.D. Title of diploma thesis: Pharmacokinetics of flavanols This work is focusing on summarizing available information about the fate of flavanols in the organism. It is necessary to know the pharmacokinetics to explain their biological effects. In contrast to other flavonoids, they occur in the form of aglycones in plant foods. Galoylation, polymerization and optical isomerism have an important influence on the pharmacokinetics. Partial absorption of monomers begins in the small intestine after oral ingestion. In addition to the liver, the extensive metabolic changes take place even in the enterocytes. The resulting metabolites enter the circulation or they are effluxed back into the intestinal lumen, especially in the case of (epi)catechin sulfates. Epicatechin and catechin are present almost exclusively as glucuronides, sulfates or methylated compounds in the plasma. On the contrary, free unconjugated forms prevail within the gallates. The extent of their absorption is lower. They are excreted via biliary excretion, while other catechins are quickly eliminated by the kidneys in urine. The bioavailability of the parent...

The object of this thesis was the study on the pharmacokinetics and biotransformation of selected abused new synthetic drugs, specifically belonging to cathinone and aminoindane groups, in experimental rats. This work consisted of two parts: a biotransformation study of mephedrone, methylone, 5,6-methylenedioxy-2- aminoindane (MDAI) and a distribution profile study of mephedrone, methylone, MDAI and naphyrone. This document is presented as a commentary to the original papers, which were published in peer reviewed journals. The samples of blood and tissue (brain, lungs, liver) were taken at specific times after a subcutaneous single bolus dose of the studied drugs. The urine samples for the biotransformation studies were collected over a 24-hour period following the sc. dose. The LC/HRMS method was used for metabolite detection and quantitative analysis. Our findings not only included testing metabolites of the aforementioneddrugs against the synthesized reference standards, but also discovering previously unknown metabolites of these drugs. Ten phase I and five phase II metabolites aside from the parent drug were identified in urine after mephedrone administration by comparison of their spectra against those of reference standards and/or MS2 spectra of previously identified metabolites. The main...

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Kateřina Erbenová Supervisor: PharmDr. Martina Čečková, Ph.D. Title of diploma thesis: Study of interactions antiretroviral drug maraviroc with drug transporters ABCB1 and ABCG2. Maraviroc is inhibitor of CCR5 HIV virus entry into the cells representing one of the important components of antiretroviral therapy. To optimize the treatment strategies and minimize the therapeutic risks of maraviroc-containing combination antiretroviral therapy, it is important to know the interactions of this drug with other antiretrovirals. In particular, interaction on membrane transporters may affect pharmacokinetics and thereby the tissue concentrations of administered drugs, leading to insufficient efficacy of the therapy or increased toxicity. The aim of this study was to experimentally evaluate interaction of maraviroc with the two most important active drug transporters of the ABC transporter superfamily, ABCB1 (P-glycoprotein) and ABCG2 (BCRP). Using in vitro methods employing cell lines we aimed to fulfil two main goals: (1) to evaluate the inhibitory effect of maraviroc on ABCB1 and ABCG2 transporters and (2) to study if any of these transporters could transfer maraviroc as their substrate. The data...

Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Daniela Uramová Supervisor: Assoc. Prof. Přemysl Mladěnka, Pharm.D., Ph.D. Title of diploma thesis: Pharmacokinetics of flavanones The aim of the work was to summarize the available information regarding the fate of the flavanones in the human organism. These flavonoids are a common part of human diet, and therefore oral administration is the most relevant and examined. There are many obstacles in the digestive tract which are lowering their absorption. Flavanones in human food occur mainly in the form of glycosides, and therefore must be deglycosylated by the β- glucosidase enzyme family. Aglycones are absorbed mainly in the small intestine. Flavonoids in the form of non-cleavable glycosides (e.g., rutinosides) are absorbed in the distal parts of the digestive system, after cleavage of the sugar component by intestinal bacteria. They also decompose the flavanone ring. This leads to substances with a phenylpropionic structure which can be absorbed. In general, flavanones are subject to extensive metabolism by cytochrome P450, not only in the liver but also in the enterocytes, which greatly limits their bioavailability. They are also rapidly conjugated with glucuronic or sulfuric acid. The...