Erstellung eines Bewertungssystems für OTC-Arzneimittel unter Anwendung des Analytischen Hierarchieprozesses

Nahezu die Hälfte der abgegebenen Medikamente in deutschen Apotheken entfällt auf rezeptfreie Arzneimittel (Over-The-Counter (OTC)-Arzneimittel). Der Großteil davon wird ohne Verschreibung abgegeben und ist somit der Selbstmedikation zuzuordnen, was den hohen Stellenwert des Selbstmedikationssektors...

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Bibliographic Details
Main Author: Zahn, Astrid Alexandra
Contributors: Culmsee, Carsten (Prof. Dr.) (Thesis advisor)
Format: Doctoral Thesis
Published: Philipps-Universität Marburg 2014
Online Access:PDF Full Text
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Non-prescription drugs (Over-The-Counter (OTC-) drugs) account for nearly half of all drugs distributed in German pharmacies. Most of them are available without a doctor’s prescription and are used by individuals to treat self-recognised or self-diagnosed symptoms. This self-medication is an important element in a modern healthcare system. At the same time, it enhances the pharmacist's position to assess the individual patient’s potential and limitations for self-medication and accordingly recommend an appropriate drug. Inevitably, this leads to the question as to the criteria on which the pharmacist’s recommendation of an OTC product is founded. In order to heed scientific principles and ensure a continuous improvement of adequate drug supply and safety of drug therapies, the pharmacist’s decision for OTC-products must be based on a differentiated and an evidence-based assessment. A review of the available research literature has shown that, to date, a convenient, scientifically established and well-structured tool for a comparative evaluation and classification has not been developed. The primary aim of the present thesis was to set up an evidence-based transparent scoring system for OTC-drugs. Furthermore, the findings resulting therefrom should be offered to the pharmacist in a plausible and clear manner. The first case study chosen was the acute, productive cough caused by an upper respiratory tract infection (URTI) and the second study the acute, dry cough also caused by URTI. The indication acute cough was selected on account of its significant relevance in self-medication measures and the high counselling activity required from the pharmacist. The first part of the thesis aimed at establishing the status quo of drug assessment in Germany by way of a questionnaire. The questionnaire was prepared to gain insight and information on the methods and criteria used by eleven organizations and scientific publishers for assessing drugs. The results, after evaluation of the questionnaire, could then be useful for the development of a scoring system for OTC-drugs. In the second part of the thesis after evaluation of the status quo analysis, a scoring system geared to the defined application examples was developed. Due to the many differences, assessment of criteria and evidence levels the subject matter implied an immensely complex as well as initially unstructured decision-making problem. For this reason, the whole process was supported by the Analytic Hierarchy Process (AHP)- a method that is successfully applied to a wide variety of multifactorial, multilayer decision-making problems. It also helps to find scientifically comprehensible solutions with due regard to all relevant parameters. The selected synthetic drugs (acetylcysteine, ambroxol, bromhexine, dextromethorphan, pentoxyverine) and the phytopharmaceuticals (cineole, ivy, marshmallow, Pelargonium sidoides, thyme extract) were investigated, compared and assessed based on the predeter-mined influencing variables adverse events and efficacy. Adverse events were analysed through the evaluation of drug factsheets in the versions currently available. To assess drug efficacy, a comprehensive and systematic literature review was conducted in line with pre-determined inclusion and exclusion criteria. For the purpose of analysing efficacy, the evidence levels I to III were used. In accordance with the principle of accepting the best available evidence, evidence level IV was only used when no evidence for levels I to III could be obtained. Moreover, German-language guidelines were utilized to evaluate drug efficacy. Finally, the results obtained from the analysis of the drug factsheets, evidence levels and guidelines were applied to the AHP-structure and afterwards visualized in a comprehensive overview. An easy and generally comprehensible code-coloured pattern according to the traffic light system was applied. The categories A (green), B (yellow) and C (red) were linked with intervals so that a classification into the individual categories could be made. At the same time, a score was assigned to the drugs to enable the user to directly perceive the comparative evaluation of the drugs. The overall results of the two case studies were presented in one single image whereby the results were listed separately for the criteria adverse events and efficacy. The analysis of the adverse events revealed that the selected OTC drugs are generally well tolerated with a positive safety profile. All phytopharmaceuticals were classified in category A, whereas all synthetic drugs had to be assigned to category B. The comprehensive and systematic literature review revealed that for the majority of the selected OTC drugs there is no conclusive evidence regarding their efficacy in cases of acute cough with the exception of Pelargonium sidoides extract and, to a very small extent, cineole, dextromethorphan and marshmallow extract. Eight studies were taken into account for Pelargonium sidoides extract of which seven studies were randomized, placebo-controlled trials and therefore allocated to evidence level Ib. The remaining study was allocated as a prospective cohort study to evidence level III. Two of these eight studies were carried out as randomized, placebo-controlled dose-finding studies with tablets; the others were based on the administration of drops. One study for evidence level Ib and another study for evidence level III were included with respect to cineole. Regarding the efficacy of dextromethorphan one study for evidence level Ia and one study of evidence level Ib were incorporated. Just one study for evidence level III was included for marshmallow extract. Since no evidence level I-III for the efficacy of acetylcysteine, ambroxol, bromhexine, ivy and thyme extract as well as for pentoxyverine could be established, evidence level IV had to be chosen. The finding that there is no reliable evidence for the efficacy of OTC drugs in cases of acute cough is shared in the publications and guidelines consulted during the course of this work. Pelargonium sidoides extract drops were classified in category B, whereas all other investigated OTC drugs had to be allocated to category C.