[The similarity of drug names as a possible cause of confusion: Analysis of data from outpatient care]. / Die Ähnlichkeit von Medikamentennamen als mögliche Ursache von Verwechslungen ­ eine Untersuchung von Daten aus der ambulanten Versorgung.

BACKGROUND: The incidence of adverse drug events (ADE) described in the literature varies between 6.5 and 20 %. Furthermore, it is assumed that up to 29 % of ADE are due to medication errors as a result of confusion because of similarities in spelling (sound alike) or in name, physical appearance or packaging (look alike). Studies dealing with the so-called "LASA" issue were mostly carried out in inpatient care. As far as we know, no systematic investigations into this subject have been carried out for the outpatient sector where patients themselves take care of the application of their medication. In addition, there is no documentation about medication errors in the home setting. The aim of the present study is to describe the importance of the LASA issue in the home setting where medication errors are likely to occur due to similarity of drug names. METHODS: In this context, the similarity of names of prescription drugs was systematically analyzed. We examined in detail how often prescription drug pairings showing orthographic and phonetic similarity were dispensed in the investigation period to an individual patient at the same time. Orthographic similarity was defined as relevant at a Levenshtein index value of ≤ 0.4. This corresponds to the similarity measures of the drugs listed in the LASA public lists and means that the similarity in the lettering of two drug names amounts to at least 60 %. Phonetic similarity was analysed using the Cologne Phonetic ("Kölner Phonetik") for the German language. RESULTS: A total of 255,770 prescriptions were included in the analysis. In 11.4 %, drug pairings were detected that fall below the critical orthographic similarity threshold (Levenshtein index value ≤ 0.4), which represents an increased likelihood of medication error due to the critical similarity of drug names in this fraction. Within this group of "LASA drugs" different degrees of similarity were identified. Even drug pairings with very high orthographic similarity (Levenshtein index value from ≤ 0.1 and 0.1 to ≤ 0.2, 12.4 % and 3.6 % of the drug pairings, respectively) were detected. These drug pairings were mostly different in strength while active ingredients, manufacturer name and pharmaceutical form were the same. For the majority of drug pairings (84 %), the orthographic similarity was lower and showed a Levenshtein index value of ≥ 0.2 to 0.4. Despite different active ingredients, there is a degree of similarity resulting from both identical manufacturer name and pharmaceutical form appearing as part of the drug name. At the phonetic level, the analysis shows comparable frequency of similarity of drug pairings that are subject to potential medication error. DISCUSSION: For the first time, a study was carried out in the outpatient setting recording the incidence of drug pairings that carry a risk for medication errors resulting from patients' confusion over too similar drug names. In the light of the age structure of the patients to whom these look- or sound-alike drugs are prescribed, we can assume that there is a considerable risk of ADE. The conceivable consequences of such medication errors on a pharmacological level range from relatively harmless to potentially highly dangerous. CONCLUSION: There is a major need to fully inform patients about this risk of confusion and subsequent medication errors with certain drug combinations. The similarity structures of drug pairings identified in this study could serve as a basis for developing an appropriate information routine.

[A structured case analysis from the Critical Incident Reporting System of the German Medical Association and the National Association of Statutory Health Insurance Physicians]. / Eine strukturierte Fallanalyse aus dem Critical Incident Reporting System der Bundesärztekammer und Kassenärztlichen Bundesvereinigung.

BACKGROUND: Reporting systems for near misses are necessary to improve patient safety. In Germany, different systems are publicly available on both a national and regional level or as systems related to various medical domains. In contrast with the British Registry, our reporting systems still lack systematic evaluation. Using the Open-Task-Process Model (OPT model) one case of CIRSmedical (www.cirsmedical.de) was selected for a systematic analysis. METHOD: Case 148384 reports on a patient with a tentative diagnosis of pulmonary embolism with an oxygen saturation of 71 %. The attending physician was ordered to leave the patient to participate in the daily team meeting. After 40minutes, the nurses transferred the patient from the emergency department to the ICU. The OPT model systematically checks the properties of all tasks in a given process and matches them to requirements or solving capacities of the task. RESULTS: The analysis manifests some structural problems: Although the case was not very difficult (high priority, but a frequent problem), the solving capacities were not adequate in order to avoid errors. Since the physician left the patient, the loyalty toward medical standards and the team error correction activity were low. The team did not intervene to prevent the doctor from leaving his patient. CONCLUSION: The OPT model allows for the analysis of both single cases and complete data sets of CIR systems and is able to disclose structural problems of clinical management.

Supporting breast cancer decisions using formalized guidelines and experts decision patterns: initial prototype and evaluation.

Transparent decisions and its documentation of breast cancer patients' therapy are getting more important especially since modern therapeutic approaches favor personalized forms of treatment. The medical decisions for a treatment are very complex, because there are rules and different options for each patient. To support the decision process, we analyzed the current decision rules and implemented them in a prototype of a rule-based expert system. Thus, this system shall support the quality assurance regarding transparent documentation of individualized therapeutic decisions. For evaluating the system, we used data from a state tumor center and compared the decisions suggested by our system with expert ones. The system and the expert approach will be compared with each other as well as the differences in the treatment decisions. The first preliminary results show us that the human factor-like must be considered by creating a decision support system. The prototype delivers first results, which are restricted, but the results are promising for further developments.

Expression and regulation of luteinizing hormone/human chorionic gonadotropin receptors in ovarian cancer and its correlation to human chorionic gonadotropin-doxorubicin sensitivity.

OBJECTIVE: Ovarian cancer cell lines and tissues express gonadotropin receptors. Conjugation of cytostatics to ligands of these receptors may increase the specificity of cytotoxic drugs. STUDY DESIGN: Toxicity of doxorubicin-human chorionic gonadotropin conjugates was determined in 4 ovarian cancer cell lines. Expression and regulation of luteinizing hormone/human chorionic gonadotropin receptors were analyzed before and after treatment with human chorionic gonadotropin, epidermal growth factor, and 8-bromo-cyclic adenosine monophosphate with a nested reverse transcriptase-polymerase chain reaction approach. RESULTS: Toxicity of human chorionic gonadotropin-doxorubicin conjugates was increased compared with unconjugated doxorubicin in OVCAR-3 cells. However, drug conjugates failed to demonstrate increased toxicity in other cell lines, especially after preincubation with human chorionic gonadotropin. All cell lines expressed luteinizing hormone/human chorionic gonadotropin receptors. Receptor expression in OVCAR-3 cells was not effected by human chorionic gonadotropin, endothelial growth factor, or 8-bromo-cyclic adenosine monophosphate treatment. In other cell lines, receptor expression was down-regulated by these agents. CONCLUSION: Cytotoxic activity of doxorubicin was increased specifically by conjugation to human chorionic gonadotropin. However, the regulation of luteinizing hormone/human chorionic gonadotropin receptor expression and other compounds may reduce the drug-uptake of the conjugates.

Cytotoxic effect of conjugates of doxorubicin and human chorionic gonadotropin (hCG) in breast cancer cells.

Cytotoxic activity of drug conjugates of human chorionic gonadotropin (hCG) and doxorubicin alone was investigated compared to doxorubicin in breast cancer cells with and without expression of hCG receptors. Expression of hCG receptor was determined in MCF-7 and MB231 breast cancer cell line using a multiplex nested rt-PCR approach. The entire sequence of mRNA encoding for hCG receptor was detected in MCF-7 but not in MB231 breast cancer cell line. Cytostatic effect of doxorubicin-hCG conjugates was investigated in these cell lines in comparison to unconjugated doxorubicin. The number of viable cells was determined after 24, 48, 72, 96, and 120h. To exclude non-specific uptake of the carrier hCG from the culture media, a similar experiment was performed with albumin-doxorubicin conjugates. The number of viable cells decreased in a concentration depending manner after doxorubicin and hCG-doxorubicin conjugate treatment. However, the cytotoxic effect of hCG-doxorubicin conjugate was 10-fold increased compared to unconjugated doxorubin in hCG-receptor positive MCF-7 but not in hCG-receptor negative MB231 cells. Albumin-doxorubicin conjugates showed no increased toxicity compared to doxorubicin. We conclude that the cytotoxic effect of hCG-doxorubicin conjugates is mediated specifically via the hCG receptor. By using hCG conjugates, the development of more selective cytostatics can be achieved.