Patients on anti-retroviral (ARV) drug treatment are sometimes simultaneously taking other prescribed drugs and/or over-the-counter drugs and/or herbal remedies. Pharmacokinetic drug-drug or herb-drug interactions can occur in these patients, which might be synergistic or antagonistic in nature leading to increased or decreased bioavailability of the ARV. Consequences of bioavailability changes may either be adverse effects due to increased plasma levels, or lack of pharmacological responses due to decreased plasma levels. The aim of this study is to determine if pharmacokinetic interactions exist between selected commercially available herbal products, namely Linctagon Forte®, Viral Choice® and Canova® and the ARV, indinavir, in terms of transport and metabolism in cell culture models. Bi-directional transport of indinavir was evaluated across Caco-2 cell monolayers in four experimental groups, namely indinavir alone (200 μM, negative control group), indinavir in combination with Linctagon Forte®, indinavir in combination with Viral Choice® and indinavir in combination with Canova® at three different concentrations. Verapamil (100 μM), a known P-gp inhibitor, was combined with indinavir in the positive control group. Samples obtained from the transport studies were analysed by means of a validated high performance liquid chromatography (HPLC) method. The apparent permeability coefficient (Papp) values were calculated from the transport results in both directions and the efflux ratio (ER) values were calculated from these Papp values. The metabolism of indinavir was determined in LS180 cells in the same groups as mentioned for the transport study but with ketoconazole (40 μM), a known CYP3A4 inhibitor, as the positive control group. Indinavir and its predominant metabolite (M6) were analysed in the metabolism samples by means of liquid chromatography linked to mass spectroscopy (LC/MS/MS) to determine the effect of the herbal products on the biotransformation of indinavir. The BL-AP transport of indinavir increased in a concentration dependent way in the presence of Linctagon Forte® and Viral Choice® when compared to that of indinavir alone (control group). Canova® only slightly affected the efflux of indinavir compared to that of the control group. Noticeable increases in the efflux ratio values of indinavir were found for Linctagon Forte® and Viral Choice®, whilst the effect of Canova® on the efflux ratio value was negligible. There was a pronounced inhibition of the metabolism of indinavir in LS180 cells over the entire concentration range for all the herbal products investigated in this study. These in vitro pharmacokinetic interactions indicate the selected herbal products may affect indinavir’s bioavailability, but the clinical significance needs to be confirmed with in vivo studies before final conclusions can be made. / MSc (Pharmaceutics), North-West University, Potchefstroom Campus, 2015

Tuberculosis (TB) is the world’s most deadly infectious disease and causes enormous public health problems. The comorbidity with HIV and the rise of multidrug-resistant TB strains impede successful therapy through drug-drug interactions and the lack of efficient second-line treatments. The aim of this thesis was to support the improvement of anti-TB therapy through development of pharmacometric models, specifically focusing on the novel drug bedaquiline, pharmacokinetic interactions and methods for pooled population analyses. A population pharmacokinetic model of bedaquiline and its metabolite M2, linked to semi-mechanistic models of body weight and albumin concentrations, was developed and used for exposure-response analysis. Treatment response was quantified by measurements of mycobacterial load and early bedaquiline exposure was found to significantly impact the half-life of bacterial clearance. The analysis represents the first successful characterization of a concentration-effect relationship for bedaquiline. Single-dose Phase I studies investigating potential interactions between bedaquiline and efavirenz, nevirapine, ritonavir-boosted lopinavir, rifampicin and rifapentine were analyzed with a model-based approach. Substantial effects were detected in several cases and dose-adjustments mitigating the impact were suggested after simulations. The interaction effects of nevirapine and ritonavir-boosted lopinavir were also confirmed in patients with multidrug-resistant TB on long-term treatment combining the antiretrovirals and bedaquiline. Furthermore, the outcomes from model-based analysis were compared to results from conventional non-compartmental analysis in a simulation study. Non-compartmental analysis was found to consistently underpredict the interaction effect when most of the concentration-time profile was not observed, as commonly is the case for compounds with very long terminal half-life such as bedaquiline. To facilitate pooled analyses of individual patient data from multiple sources a structured development procedure was outlined and a fast diagnostic tool for extensions of the stochastic model components was developed. Pooled analyses of nevirapine and rifabutin pharmacokinetics were performed; the latter generating comprehensive dosing recommendations for combined administration of rifabutin and antiretroviral protease inhibitors. The work presented in this thesis demonstrates the usefulness of pharmacometric techniques to improve treatment of TB and especially contributes evidence to inform optimized dosing regimens of new and old anti-TB drugs in various clinical contexts.

No description available.

Introdução. A varfarina tem sido considerada a principal terapêutica anticoagulante oral há aproximadamente 50 anos, estando entre os dez medicamentos mais envolvidos com reações adversas a medicamentos (RAM), apresenta estreita janela terapêutica e complexo regime posológico, exibe enorme variabilidade doseresposta e elevado risco de interações medicamentosas (IM). Objetivo. Identificar e avaliar as IM e RAM relacionadas com a administração da varfarina. Casuística e Métodos. Trata-se de um estudo transversal. Os dados foram coletados retrospectivamente através do banco de dados informatizado do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo pertencente ao Sistema Único de Saúde. As prescrições de janeiro/2004 a dezembro/2010 dos pacientes que utilizaram varfarina foram analisadas, sendo os pacientes divididos em dois grupos: estudo (uso de vitamina K até 168 horas após prescrição de varfarina) e controle. Posteriormente, as prescrições medicamentosas que não continham varfarina foram excluídas da análise. As informações coletadas incluíram idade, gênero, raça, unidade de atendimento, diagnóstico clínico, doses e medicamentos, e exames laboratoriais. As IM com varfarina foram classificadas em risco A, B, C, D e X de acordo a base de dados da Lexi-Interact(TM) Online. Foi realizada análise descritiva e analítica (p<0,05). Resultados e Discussão. Foram identificados 3048 pacientes, os quais receberam 154161 prescrições medicamentosas (42120 continham varfarina). A idade média foi de 55,8 (±19,3) anos, 53,2% do gênero feminino, prevalência de idosos (48,1%) e do diagnóstico outras doenças cerebrovasculares específicas (4,3%). Os valores médios da international normalized ratio (INR) (2,4±1,7) e dose de varfarina (5,1±1,8mg) encontraram-se dentro dos preconizados pelos protocolos terapêuticos. Foi observado que 66,4% dos pacientes realizaram uso de polifarmácia, o que pode elevar o risco de IM. Além disso, 63,2% dos pacientes apresentaram prescrição(ões) de medicamentos classificados como risco D e/ou X, com média de 1,4 (±0,4) medicamento/prescrição, destacando-se o ácido acetilsalicílico e amiodarona. Quando comparado grupo de estudo (n=429) versus controle (n=2619), houve diferença estatisticamente significativa na idade média (anos) (59,0±18,8 vs. 55,5±19,3; p<0,000), número médio de medicamentos/prescrição (7,1±2,8 vs. 6,2±2,8; p<0,000), número médio de medicamentos de Risco D e X de IM por prescrição (1,4±1,3 vs. 1,0±1,0; p<0,000), albumina sérica (g/dL) (3,4±0,6 vs. 3,7±0,6; p<0,000), aspartato aminotransferase (U/L) (60,7± 200,6 vs. 41,5±84,5; p<0,005) e INR (4,9±3,4 vs. 2,1±0,7; p<0,000), fatores estes que podem ter contribuído para ocorrência de RAM no grupo de estudo. Conclusão. Observou-se elevada ocorrência de possíveis IM e RAM nos usuários de varfarina, as quais podem comprometer a efetividade e segurança do tratamento farmacológico. Como possíveis fatores de risco para ocorrência de RAM, destacam-se elevados valores de idade, número de medicamentos/prescrição, prescrição de medicamentos classificados como risco D e/ou X, de INR e de aspartato aminotransferase, e valores diminuídos de albumina sérica. / Introduction. Warfarin has been considered the main oral anticoagulant therapy about 50 years ago and is among the ten drugs most commonly involved in adverse drug reactions (ADR), has a narrow therapeutic index and complex dosage regimen, exhibits enormous variability dose-response and high risk drug-drug interactions (DDI). Objective. To Identify and evaluate DDI and ADR related to the administration of warfarin. Casuistry and Methods. This was a cross sectional study. Data were collected retrospectively through the computerized database of the Faculty of Medicine of Ribeirao Preto Hospital, University of Sao Paulo linked to the Unified Health System. The prescriptions of the January/2004 to December/2010 of patients using warfarin were analyzed, and the patients were divided into two groups: study (utilization of vitamin K until 168 hours after prescribing warfarin) and control. Thereafter, the drug prescriptions that did not contain warfarin were excluded from analysis. Information collected included age, gender, race, patient service center, clinical diagnosis, dosages and drugs, and laboratory exams. The warfarin DDI were classified at risk A, B, C, D and X according to the database Lexi-Interact (TM) Online. Descriptive and analytical analysis were performed (p<0.05). Results and Discussion. We identified 3048 patients who received 154,161 drug prescriptions (42,120 contained warfarin). The mean age was 55.8 (±19.3) years, 53.2% female, prevalence of elderly (48.1%) and other cerebrovascular diseases specific diagnosis (4.3%). The average values of international normalized ratio (INR) (2.4±1.7) and warfarin dose (5.1±1.8mg) were within those recommended by therapeutic protocols. It was observed that 66.4% of patients received polypharmacy, which can raise the risk of DDI. In addition, 63.2% of patients had prescription(s) of drugs classified as D or X risk, with an average of 1.4 (±0.4) drugs per prescription, especially aspirin and amiodarone. Compared study group (n=429) versus control (n =2619), there was a statistically significant difference in mean age (years) (59.0±18.8 vs. 55.5±19.3; p<0.000), average number of medications/prescriptions (7.1±2.8 vs. 6.2±2.8; p<0.000), mean number of drugs with risk D and X DDI/prescription (1.4±1.3 vs. 1.0±1.0, p<0.000), serum albumin (g/dL) (3.4±0.6 vs. 3.7±0.6; p<0.000), aspartate aminotransferases (U/L) (60.7±200.6 vs. 41.5±84.5; p<0.005) and INR (4.9±3.4 vs. 2.1±0.7; p<0.000), factors that may have contributed to the occurrence of ADR in the study group. Conclusion. There was a high occurrence of possible DDI and ADR in patients treated with warfarin, which may compromise the effectiveness and safety of pharmacological treatment. Noteworthy is the high values of age, number of medications/prescriptions, prescription drugs classified as risk D or X, INR and aspartate aminotransferases, and lower values of serum albumin as potential risk factors for the occurrence of ADR.

Wang, Xiaoan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 145-166). / Abstracts in English and Chinese. / Table of Contents --- p.I / Acknowledgements --- p.VI / Publications --- p.VII / Abstract (in English) --- p.VIII / Abstract (in Chinese) --- p.X / List of Figures --- p.XII / List of Tables --- p.XVI / List of Abbreviations --- p.XVII / Chapter Chapter One. --- Introduction --- p.1 / Chapter 1.1 --- Overview of oseltamivir --- p.1 / Chapter 1.1.1 --- General description of oseltamivir --- p.1 / Chapter 1.1.2 --- Pharmacological activities of oseltamivir --- p.3 / Chapter 1.1.3 --- Pharmacokinetics of oseltamivir --- p.3 / Chapter 1.1.3.1 --- Absorption of oseltamivir --- p.4 / Chapter 1.1.3.2 --- Distribution of oseltamivir --- p.5 / Chapter 1.1.3.3 --- Metabolism of oseltamivir --- p.6 / Chapter 1.1.3.4 --- Elimination of oseltamivir --- p.8 / Chapter 1.1.4 --- Side effects and toxicities of oseltamivir --- p.9 / Chapter 1.2 --- Overview of Chinese medicine formulae CMF1 (Yinqiaosan and Sangjuyin) --- p.9 / Chapter 1.2.1 --- Background and clinical use of CMF1 --- p.9 / Chapter 1.2.2 --- Quality control of CMF1 by manufacturer --- p.11 / Chapter 1.2.3 --- Major active components of CMF1 --- p.12 / Chapter 1.3 --- Previous studies on herb-drug interactions between O and CMF1 --- p.18 / Chapter 1.4 --- Rationale of the current study --- p.19 / Chapter 1.5 --- objectives --- p.19 / Chapter Chapter Two. --- Identification and quantification of major marker compounds in Yinqiaosan and Sangiuyin products --- p.20 / Chapter 2.1 --- Introduction --- p.20 / Chapter 2.2 --- Materials and methods --- p.23 / Chapter 2.2.1 --- Chemicals --- p.23 / Chapter 2.2.2 --- Instruments --- p.24 / Chapter 2.2.3 --- Chromatographic conditions --- p.24 / Chapter 2.2.4 --- Preparation of standard solutions --- p.25 / Chapter 2.2.5 --- Calibration curves --- p.26 / Chapter 2.2.6 --- Validation of the assay method --- p.26 / Chapter 2.2.7 --- Sample preparations for Yinqiaosan and Sangjuyin products --- p.27 / Chapter 2.2.7.1 --- Sample extraction from Yinqiaosan or Sangjuyin granules --- p.27 / Chapter 2.2.7.2 --- Sample extraction from Yinqiaosan or Sangjuyin tablets --- p.27 / Chapter 2.2.7.3 --- Sample extraction recoveries --- p.27 / Chapter 2.3 --- Results and discussions --- p.28 / Chapter 2.3.1 --- Chromatography --- p.28 / Chapter 2.3.2 --- Linearity and sensitivity --- p.33 / Chapter 2.3.3 --- Accuracy and precision --- p.33 / Chapter 2.3.4 --- Stability --- p.36 / Chapter 2.3.5 --- Contents of identified active components in commercial available Yinqiaosan or Sangjuyin products and CMF1 --- p.36 / Chapter 2.3.6 --- Sample extraction recovery --- p.40 / Chapter 2.4 --- Conclusion --- p.43 / Chapter Chapter Three. --- Effect of CMF1/CMF1 components on the metabolism of oseltamivir and related mechanistic studies --- p.44 / Chapter 3.1 --- Introduction --- p.44 / Chapter 3.2 --- Materials and methods --- p.47 / Chapter 3.2.1 --- Materials --- p.47 / Chapter 3.2.2 --- "Verification of metabolism of O in rat GI tract, plasma and liver microsome" --- p.48 / Chapter 3.2.3 --- Inhibition of metabolism of O by CMFl/CMFl components --- p.49 / Chapter 3.2.3.1 --- In vitro inhibition of metabolism of O in rat plasma --- p.49 / Chapter 3.2.3.2 --- In vitro inhibition of metabolism of O in rat liver microsome (RLM) --- p.49 / Chapter 3.2.4 --- Mechanistic study of enzyme inhibition of O in recombinant human Carboxylesterase 1 (hCE 1) --- p.50 / Chapter 3.2.5 --- Sample preparation and LC/MS/MS analysis --- p.50 / Chapter 3.2.6 --- Data analyses --- p.52 / Chapter 3.3 --- Results --- p.53 / Chapter 3.3.1 --- "Verification of metabolism of O in rat GI tract, plasma and liver microsome" --- p.53 / Chapter 3.3.2 --- Inhibition of metabolism of O by CMF1/CMF1 components --- p.53 / Chapter 3.3.2.1 --- Enzyme inhibition of metabolism of O by CMFl/CMF1 components in rat plasma --- p.53 / Chapter 3.3.2.2 --- Enzyme inhibition of metabolism of O by CMF1/CMF1 components in rat liver microsome (RLM) --- p.58 / Chapter 3.3.2.3 --- Selection of potent enzyme inhibitor from CMF1 --- p.60 / Chapter 3.3.4. --- Mechanistic study of enzyme inhibition of O in recombinant human Carboxylesterase 1 (hCE 1) --- p.61 / Chapter 3.4 --- Discussions --- p.63 / Chapter 3.5 --- Conclusion --- p.74 / Chapter Chapter Four. --- Effect of CMFl/CMFl components on the absorption of oseltamivir and related mechanistic studies --- p.75 / Chapter 4.1 --- Introduction --- p.75 / Chapter 4.2 --- Materials and methods --- p.79 / Chapter 4.2.1 --- Materials --- p.79 / Chapter 4.2.2 --- PAMPA permeation model --- p.80 / Chapter 4.2.2.1 --- Permeation of O and OC in PAMPA --- p.80 / Chapter 4.2.2.2 --- Sample preparation and LC/MS/MS analysis --- p.81 / Chapter 4.2.2.3 --- Data analysis --- p.81 / Chapter 4.2.3 --- Absorption of O in presence of CMF/CMFl components in Caco-2 and MDCK cell monolayer models --- p.82 / Chapter 4.2.3.1 --- Cell culture --- p.82 / Chapter 4.2.3.2 --- Preparation of loading solutions to the cell models --- p.83 / Chapter 4.2.3.3 --- Stability of O in transport buffer --- p.84 / Chapter 4.2.3.4 --- Cytotoxicity tests of O and CMFl/CMFl components --- p.84 / Chapter 4.2.3.5 --- Transport study in Caco-2 and MDCK monolayer model --- p.85 / Chapter 4.2.3.6 --- Sample preparation and LC/MS/MS analysis --- p.86 / Chapter 4.2.3.7 --- Data analysis --- p.87 / Chapter 4.2.4 --- Absorption of O in presence of CMF 1 in rat in situ single pass intestinal perfusion model --- p.88 / Chapter 4.2.4.1 --- Preparation of perfusion solutions --- p.88 / Chapter 4.2.4.2 --- Stabilities of O and arctigenin in perfusate --- p.88 / Chapter 4.2.4.3 --- Rat in situ single pass intestinal perfusion of O in presence and absence of CMFl and relevant inhibitors --- p.89 / Chapter 4.2.4.4 --- Sample preparation and LC/MS/MS analysis --- p.90 / Chapter 4.2.4.5 --- Data analysis --- p.90 / Chapter 4.3 --- Resul ts --- p.91 / Chapter 4.3.1 --- Permeation of O and OC in PAMPA --- p.91 / Chapter 4.3.2 --- Absorption of O in presence of CMF/CMF1 components in Caco-2 and MDCK cell monolayer models --- p.92 / Chapter 4.3.2.1 --- Stabilities of O in transport buffer --- p.92 / Chapter 4.3.2.2 --- Cytotoxicity tests of O and CMF1/CMF1 components in transport buffer --- p.93 / Chapter 4.3.2.3 --- Proof of O as a substrate of P-gp by Caco-2 cell model --- p.95 / Chapter 4.3.2.4 --- Effect of CMF 1 on the absorption transport of o in Caco-2 cell mode --- p.98 / Chapter 4.3.2.5 --- Effect of CMF1 components on the absorption transport of o in Caco-2 cell model --- p.102 / Chapter 4.3.2.6 --- Effect of arctigenin on bi-directional transport of o in Caco- 2 cell model --- p.106 / Chapter 4.3.2.7 --- Proof of O as a substrate of P-gp by MDCK transfected cell lines --- p.108 / Chapter 4.3.2.8 --- Bi-directional transport of O in MDCK-MDR1 cell model --- p.111 / Chapter 4.3.2.9 --- Effect of CMF 1 on the absorption transport of O in MDCK-MDR1 cell model --- p.112 / Chapter 4.3.3 --- Absorption of O in presence of CMF1 in rat in situ single pass intestinal perfusion model --- p.113 / Chapter 4.3.3.1 --- Stabilities of O and arctigenin in the perfusion buffer --- p.113 / Chapter 4.3.3.2 --- Intestinal absorption of O in presence and absence of CMF1 in rat in situ intestinal perfusion model --- p.114 / Chapter 4.4 --- Discussions --- p.116 / Chapter 4.5 --- Conclusion --- p.124 / Chapter Chapter Five. --- Preliminary evaluation of antiviral activity of CMFl/CMFl components --- p.125 / Chapter 5.1 --- Introduction --- p.125 / Chapter 5.2 --- Materials and methods --- p.128 / Chapter 5.2.1 --- Materials and animals --- p.128 / Chapter 5.2.2 --- Animal treatment --- p.129 / Chapter 5.2.3 --- Plasma sample collection and preparation --- p.130 / Chapter 5.2.4 --- Evaluation of antiviral activities of CMFl/ CMFl components --- p.130 / Chapter 5.2.4.1 --- Plaque reduction assay --- p.131 / Chapter 5.2.4.2 --- Optimization of plasma sample dilution ratio --- p.131 / Chapter 5.2.5 --- Data analyses --- p.133 / Chapter 5.3 --- Results and discussions --- p.135 / Chapter 5.3.1 --- Ex vivo evaluation of antiviral activity of CMF1 --- p.135 / Chapter 5.3.2 --- In vitro evaluation of antiviral activity of CMF1 major marker compounds --- p.139 / Chapter 5.4 --- Conclusion --- p.141 / Chapter Chapter Six. --- Overall conclusion --- p.142 / References --- p.145

<p> Malaria, Human Immunodeficiency Virus (HIV) and tuberculosis (TB) are global health problems having their worst situation in sub-Saharan Africa. Consequently, concomitant use of antimalarial, antiretroviral and antitubercular drugs may be needed, resulting in a potential risk of drug-drug interactions.</p><p>Cytochrome P-450 (CYP) enzyme induction/inhibition may lead to drug-drug interactions and can be detected by probe drugs. An analytical method was developed for the quantitation of mephenytoin, CYP2B6 and CYP2C19 probe, and its metabolites. </p><p>Induction/inhibition of principal CYP enzymes by the antimalarials; artemisinin, dihydroartemisinin, arteether, artemether and artesunate, was evaluated using the 4-hour plasma concentration ratios of probe drugs and their metabolites along with modelling the population pharmacokinetics of S-mephenytoin and its metabolites. The extent of change in enzymatic activities was different among the antimalarials, with artemisinin having strongest capacity for induction and inhibition, consequently, the strongest potential risk for drug-drug interactions. </p><p>Drug-drug interactions between the antitubercular rifampicin and the antiretrovirals nevirapine and lopinavir were assessed, in TB/HIV patients, by developing population pharmacokinetic models. Rifampicin increased nevirapine oral clearance. Simulations suggested that increasing the nevirapine dose to 300 mg twice daily when co-administered with rifampicin, would result in nevirapine concentrations above subtherapeutic levels, with minimum exposure above the recommended maximum concentration. Lopinavir is co-formulated with ritonavir in the ratio of 4:1. In children, increasing ritonavir dose four times did not completely compensate the enhancement of lopinavir oral clearance caused by rifampicin. However, the predicted lopinavir trough concentration was above the recommended minimum therapeutic concentration.</p><p>The work presented in this thesis followed an investigation line though not done for a particular drug. First the CYP enzymes involved in the interaction are identified. Afterwards, the expected drug-drug interaction is investigated where the potentially interacting drugs are concomitantly administered and an adjustment in the dose regimen is proposed that is subsequently evaluated.</p>

Malaria, Human Immunodeficiency Virus (HIV) and tuberculosis (TB) are global health problems having their worst situation in sub-Saharan Africa. Consequently, concomitant use of antimalarial, antiretroviral and antitubercular drugs may be needed, resulting in a potential risk of drug-drug interactions. Cytochrome P-450 (CYP) enzyme induction/inhibition may lead to drug-drug interactions and can be detected by probe drugs. An analytical method was developed for the quantitation of mephenytoin, CYP2B6 and CYP2C19 probe, and its metabolites. Induction/inhibition of principal CYP enzymes by the antimalarials; artemisinin, dihydroartemisinin, arteether, artemether and artesunate, was evaluated using the 4-hour plasma concentration ratios of probe drugs and their metabolites along with modelling the population pharmacokinetics of S-mephenytoin and its metabolites. The extent of change in enzymatic activities was different among the antimalarials, with artemisinin having strongest capacity for induction and inhibition, consequently, the strongest potential risk for drug-drug interactions. Drug-drug interactions between the antitubercular rifampicin and the antiretrovirals nevirapine and lopinavir were assessed, in TB/HIV patients, by developing population pharmacokinetic models. Rifampicin increased nevirapine oral clearance. Simulations suggested that increasing the nevirapine dose to 300 mg twice daily when co-administered with rifampicin, would result in nevirapine concentrations above subtherapeutic levels, with minimum exposure above the recommended maximum concentration. Lopinavir is co-formulated with ritonavir in the ratio of 4:1. In children, increasing ritonavir dose four times did not completely compensate the enhancement of lopinavir oral clearance caused by rifampicin. However, the predicted lopinavir trough concentration was above the recommended minimum therapeutic concentration. The work presented in this thesis followed an investigation line though not done for a particular drug. First the CYP enzymes involved in the interaction are identified. Afterwards, the expected drug-drug interaction is investigated where the potentially interacting drugs are concomitantly administered and an adjustment in the dose regimen is proposed that is subsequently evaluated.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2009. / Härtill 4 uppsatser.

Το mHealth, η χρήση δηλαδή φορητών τεχνολογιών για την βελτίωση των παρεχόμενων υπηρεσιών υγείας, είναι σήμερα ένα από τα πιο ταχέως αναπτυσσόμενα πεδία της ηλεκτρονικής υγείας (eHealth). Ο αριθμός των επαγγελματιών υγείας που υιοθετούν έξυπνα κινητά τηλέφωνα (smartphones) για την εκτέλεση πληθώρας λειτουργιών αυξάνεται συνεχώς, εξαιτίας των δυνατοτήτων και της φορητότητας που αυτά παρέχουν. Ταυτόχρονα, τα σφάλματα στη φαρμακευτική αγωγή είναι από τα πιο συνηθισμένα ιατρικά λάθη με επιπτώσεις τόσο στην υγεία του ασθενούς όσο και στις δαπάνες στην υγεία. Η χορήγηση φαρμάκων είναι μια πολύπλοκη διαδικασία, καθώς απαιτεί από τον ειδικό της υγείας την ανάλυση πληθώρας παραγόντων και την ανάκτηση, επεξεργασία και διαχείριση μεγάλου όγκου πληροφορίας. Σύμφωνα με τη βιβλιογραφία, η χρήση τεχνολογιών πληροφορικής για την υποβοήθηση των επαγγελματιών υγείας στη λήψη αποφάσεων κατά τη συνταγογράφηση, μπορεί να συμβάλει σημαντικά στη μείωση των σφαλμάτων φαρμακευτικής αγωγής. Στο πλαίσιο της παρούσας διπλωματικής εργασίας, προχωρήσαμε στη διερεύνηση και αξιολόγηση των σημαντικότερων εφαρμογών έξυπνων κινητών συσκευών για το φάρμακο, με στόχο την εξαγωγή χρήσιμων συμπερασμάτων για τα χαρακτηριστικά και τις λειτουργίες που ενσωματώνουν. Ένα από τα βασικά συμπεράσματα της έρευνας ήταν η απουσία αντίστοιχης εφαρμογής για τα φάρμακα που είναι εγκεκριμένα από τον Εθνικό Οργανισμό Φαρμάκων (ΕΟΦ). Ως εκ τούτου, προχωρήσαμε στο σχεδιασμό και την ανάπτυξη εφαρμογής για τον έλεγχο ασυμβασιών μεταξύ φαρμάκων, η οποία παρέχει επιπλέον τη δυνατότητα προβολής πληροφοριών συνταγολογίου για τα φάρμακα του ΕΟΦ. Ο σχεδιασμός της εφαρμογής έγινε λαμβάνοντας υπόψη τις ανάγκες και τις απαιτήσεις μελλοντικών χρηστών, όπως οι επαγγελματίες υγείας και οι ασθενείς, προκειμένου να διασφαλιστεί η λειτουργικότητα και η ευχρηστία της. Η εν λόγω εφαρμογή προορίζεται για έξυπνες κινητές συσκευές που διαθέτουν λειτουργικό σύστημα Android, ενώ η πληροφορία που ενσωματώνει βασίζεται αποκλειστικά στο εθνικό συνταγολόγιο του ΕΟΦ. / Mobile Health or mHealth, namely the use of mobile and wireless technologies in order to improve health services and achieve health goals, is today one of the most rapidly expanding fields of electronic health (eHealth). The number of health professionals that adopt smartphones to perform multiple tasks, during their everyday medical practice, is increasing constantly. This is due to the fact that smartphones provide advanced computing capabilities and high portability. Simultaneously, medication errors are among the most common medical errors which have negative impact both for the health of the patient and the expenditure on health sector. Drug prescribing is quite a complex procedure, considering the fact that requires the health expert to analyze multiple factors and retrieve, process, manage and digest large volume of information. According to the literature, the use of information technologies to assist health professionals in decision-making when prescribing drugs, can contribute significantly to the reduction of medication errors. In the context of our work, we explored and evaluated the major smartphone applications for drugs, aiming to the extraction of useful conclusions about the features and functions that they incorporate. One of the research key findings was the absence of a corresponding application for the drugs that are approved by the National Drug Organization of Greece. Therefore, we design and develop an application for checking drug-drug interactions which additionally provides the ability to view national formulary information about drugs. The analysis and design of the application was implemented in collaboration with future users, such as health professionals and patients, in order to ensure that will meet their needs and requirements and at the same time will remain user friendly. This application is intended for Android smart mobile devices (e.g. smartphones, tablet PCs) and the information that integrates is solely based on the national formulary of the National Drug Organization of Greece.

Background: Drug interactions resulting in adverse drug reactions (ADRs) represent a major health problem both for individuals and society in general. Post-marketing pharmacovigilance reporting databases with compiled individual case safety reports (ICSRs) have been shown to be particularly useful in the detection of novel drug - ADR combinations, though these reports have not been fully used to detect adverse drug interactions. Aim: To explore the potential to identify drug interactions using ICSRs and to develop a method to facilitate the detection of adverse drug interaction signals in the WHO Global ICSR Database, VigiBase. Methods: All six studies included in this thesis are based on ICSRs available in VigiBase. Two studies aimed to characterise drug interactions reported in VigiBase. In the first study we examined if contraindicated drug combinations (given in a reference source of drug interactions) were reported on the individual reports in the database, and in the second study we examined the scientific literature for interaction mechanisms for drug combinations most frequently co-reported as interacting in VigiBase. Two studies were case series analyses where the individual reports were manually reviewed. The two remaining studies aimed to develop a method to facilitate detection of novel adverse drug interactions in VigiBase. One examined what information (referred to as indicators) was reported on ICSRs in VigiBase before the interactions became listed in the literature. In the second methodological study, logistic regression was used to set the relative weights of the indicators to form triage algorithms. Three algorithms (one completely data driven, one semi-automated and one based on clinical knowledge) based on pharmacological and reported clinical information and the relative reporting rate of an ADR with a drug combination were developed. The algorithms were then evaluated against a set of 100 randomly selected case series with potential adverse drug interactions. The algorithm’s performances were then evaluated among DDAs with high coefficients. Results: Drug interactions classified as contraindicated are reported on the individual reports in VigiBase, although they are not necessarily recognised as interactions when reported. The majority (113/123) of drug combinations suspected for being responsible for an ADR were established drug interactions in the literature. Of the 113 drug interactions 46 (41%) were identified as purely pharmacodynamic; 28 (25%) as pharmacokinetic; 18 (16%) were a mix of both types and for 21 (19%) the mechanism have not yet been identified. Suspicions of a drug interaction explicitly noted by the reporter are much more common for known adverse drug interactions than for drugs not known to interact. The clinical evaluation of the triage algorithms showed that 20 were already known in the literature, 30 were classified as signals and 50 as not signals. The performance of the semi-automated and the clinical algorithm were comparable. In the end the clinical algorithm was chosen. At a relevant level, 38% were of the adverse drug interactions were already known in the literature and of the remaining 80% were classified as signals for this algorithm. Conclusions: This thesis demonstrated that drug interactions can be identified in large post-marketing pharmacovigilance reporting databases. As both pharmacokinetic and pharmacodynamic interactions were reported on ICSRs the surveillance system should aim to detect both. The proposed triage algorithm had a high performance in comparison to the disproportionality measure alone.