Biomedical subjects
Publications and source records attributed to Petra A Thürmann.
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As approximately 19% of medical errors occurring in hospitals are related to medication errors, reduction of these is one of the major goals to be achieved by healthcare providers. Medication errors may occur at different levels: i) prescribing; ii) transcription; iii) dispensing; and iv) administration. Whereas errors in transcription can be significantly reduced by computerised physician order systems, improvement of prescribing appears to be a much larger problem. Continuous support by ward pharmacists may be feasible in some hospitals, but not in the setting of ambulatory prescribing. Much hope relies on computerised physician order systems with a knowledge database for interactions, warnings on allergies and other intelligent alerts. However, these systems still have some shortcomings and it has not yet convincingly been shown that the use of this technology really improves patient safety.
Comprehensive and accurate information about the medicines available to them is a key issue for patients to participate in the decision making process of their own healthcare. One aspect of this information is the patient information leaflet provided by the manufacturer, according to national and international guidelines. The comprehensibility and user-friendliness of these manufacturers' leaflets has been tested and criticised. In addition to this information under the laws of national and international authorities, consumer-oriented websites of self-help groups are becoming a more and more relevant source of information. For most patients, the primary sources of information are healthcare professionals, such as the prescribing physicians and/or nurses or the dispensing pharmacist. The information provided for by healthcare professionals has to be tailored according to the patients' needs, where law suits against physicians often address the comprehensiveness and a lack of documentation. Improvement of individualised drug information has been shown to increase patients' satisfaction and treatment adherence, whereas the overall influence on outcome (i.e., reduction of adverse drug events) has still to be demonstrated. However, in order to achieve such a goal, striking changes in the whole system of pharmacovigilance have to be implemented with special emphasis on patients and consumers representation.
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BACKGROUND: Adequate intake of lutein is postulated to reduce the risk of age-related macular degeneration, but kinetic information for developing a dosing regimen is sparse. OBJECTIVE: The objective was to characterize lutein plasma kinetics in a multiple dosing design and to assess the effects of lutein intake on concentrations of other plasma carotenoids. DESIGN: After a run-in period of 7 d, 19 healthy volunteers were assigned to receive daily oral doses of 4.1 mg lutein (n = 8; group 1) or 20.5 mg lutein (n = 8; group 2) for 42 d or no lutein (n = 3; control group). The supplement contained 8.3% zeaxanthin relative to lutein (100%). The time profiles of plasma xanthophyll concentrations were monitored over the dosing phase, and samples were collected frequently on day 42 and for 24 d after dosing. RESULTS: Average plasma all-E-lutein concentrations increased from 0.14 to 0.52 +/- 0.13 and 1.45 +/- 0.69 micromol/L in groups 1 and 2, respectively. Dose-normalized lutein bioavailability in group 2 was approximately 60% of that in group 1. Kinetic disposition half-life did not differ significantly between groups. On average, dosing for 18 d was required to reach a >90% fraction of the steady state concentration, which is consistent with an effective half-life for accumulation of approximately 5.6 d. Plasma kinetics of all-E-lutein were paralleled by those of all-E-3-dehydro-lutein. Kinetic analysis indicated formation of all-E-3-dehydro-lutein from lutein. Lutein was well tolerated and did not affect the concentrations of other carotenoids. CONCLUSION: Long-term supplementation with 4.1 and 20.5 mg lutein as beadlets increased plasma lutein concentrations approximately 3.5- and 10-fold, respectively.
BACKGROUND: Adverse drug reactions (ADRs) contribute significantly to patient morbidity and mortality, as well as to costs for healthcare systems. Our aim was to evaluate the type and incidence of ADRs in a paediatric hospital population, comparatively ascertained by two different methodological approaches. METHODS: Our prospective study enrolled all patients admitted to two of the general children wards (46 beds) and the paediatric intensive care unit (6 beds) at the HELIOS Klinikum Wuppertal teaching hospital in Germany, over the study period of 3 months. We used two methods to detect ADRs. The intensified surveillance system relied on a trained physician conducting ward rounds and assessing patient charts. The computer-assisted screening of pathological laboratory parameters used values slightly below or above the age-specific normal range as a trigger signal for a potential ADR, which was subsequently assessed by trained personnel. RESULTS: By applying both methods simultaneously we observed that 14.1% of children experienced an ADR while they were hospitalised and 2.7% of children were admitted to hospital because of the ADR. Intensified surveillance resulted in the detection of 101 ADRs in 11.9% of patients, predominantly presenting with gastrointestinal symptoms, skin and CNS disorders; computer-assisted screening identified 45 ADRs in 5.7% of patients, mainly with drug-induced blood dyscrasia and liver damage. Furthermore, the ADRs detected by the intensified method were more severe, affected younger children and showed a closer causal attributability to the reaction than the ADRs observed by the computerised method. The spectra of drugs involved were similar, with the anti-infectives being suspected most frequently. The sensitivities of the intensified surveillance system and the computerised surveillance screening came to 67.2% and 44.8%, respectively, with computer-assisted screening having a specificity of 72.8%. The mean positive predictive value of the pathological laboratory values under surveillance by computer-assisted screening was 18.6%. Approximately 25% of ADR-related drugs administered were used for off-label indications. CONCLUSION: Using the published literature for comparison, we found that ADRs occur as frequently in paediatric patients as in adult patients. Intensified surveillance and computerised surveillance applied in the paediatric setting show substantial differences in their detection specificities. A higher number of and more severe ADRs can be detected by intensified surveillance than by computerised surveillance, but require higher personnel resources.
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BACKGROUND: Zeaxanthin is hypothesized to reduce the risk of age-related macular degeneration; however, kinetic information is limited. OBJECTIVES: The objective was to investigate the plasma kinetics of synthetic zeaxanthin after repeated oral doses and to assess the possible influence of other carotenoids on plasma zeaxanthin concentrations. DESIGN: After a run-in of 3 d, 20 healthy volunteers assigned to 2 parallel dose groups received once daily oral doses of either 1 mg (1.76 micro mol) or 10 mg (17.6 micro mol) zeaxanthin for 42 d. Plasma concentration-time profiles on days 1 and 42, concentrations immediately before zeaxanthin intake during the dosing period, and concentrations after the last dose until day 76 were monitored. RESULTS: all-E-Zeaxanthin concentrations increased from 0.048 +/- 0.026 micro mol/L at baseline to 0.20 +/- 0.07 and 0.92 +/- 0.28 micro mol/L with 1 and 10 mg zeaxanthin, respectively. The dose-normalized bioavailability of all-E-zeaxanthin after the10-mg dose was 40% lower (P < 0.001) than after the 1-mg dose. Other kinetic parameters did not differ significantly between groups. After 17 d of dosing, >90% of steady state concentrations were reached, which was compatible with an effective half-life for accumulation of 5 d. The terminal elimination half-life was 12 +/- 7 d (n = 20). The time course of plasma all-E-3-'dehydro-lutein concentrations resembled that of all-E-zeaxanthin. The data provided evidence that all-E-3-'dehydro-lutein was derived from all-E-zeaxanthin. Concentrations of other carotenoids were not affected. Zeaxanthin was well tolerated. CONCLUSION: Long-term oral intake of 1 and 10 mg zeaxanthin as beadlets increases plasma zeaxanthin concentrations approximately 4- and 20-fold, respectively. Evidence that all-E-3-dehydro-lutein is formed from zeaxanthin was strong.
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Adverse drug events (ADEs) contribute significantly to patient morbidity and mortality as well as to cost for healthcare providers and society. Since only serious ADEs will result in hospitalisation, the evaluation of ADEs leading to hospitalisation reflects safety and appropriateness of ambulatory prescribing. ADEs occurring during hospitalisation may result from the special clinical situation of hospitalised patients; high degree of severity of diseases (e.g., renal failure, necessity of intensive care) and specific drugs administered only in hospitals. Moreover, the number of diagnostic and therapeutic procedures carried out daily puts the hospitalised patient at an extremely high risk for ADEs.
BACKGROUND: Bioavailability of beta-carotene is highly variable and depends on the source, the formulation and other nutritional factors. OBJECTIVE: It was the aim of the study to compare beta-carotene plasma response to b-carotene dosing with two commercially available drinks, containing beta-carotene from carrot juice or as water dispersible beta-carotene powder. Design In a randomized, parallel group study design, 4 volunteers per group received daily beta-carotene doses of 6-7 or 18-22 mg of either drink over 6 weeks. Blood samples for determination of carotenoid and vitamin A plasma concentrations were collected before supplementation and over the dosing period. RESULTS: Apparent steady-state beta-carotene concentrations were attained after 40 days of supplementation. Consumption of the beverage containing beta-carotene as a water dispersible powder resulted in a higher response of beta-carotene plasma concentrations with increments of 3.84 +/- 0.60 micromol/L (p < 0.05, dose: 7.2 mg/d) and 5.04 +/- 0.72 micromol/L (p < 0.05, dose: 21.6 mg/d), respectively, in comparison to the carrot juice-based drink with increments of 0.42 +/- 0.33 micromol/L (dose: 6 mg/d) and 1.71 +/- 0.55 micromol/L (dose: 18 mg/d), respectively. beta-carotene was cleared from the plasma with an apparent half-life of 6-11 days. Plasma concentrations of alpha-carotene, beta-cryptoxanthin, lutein, zeaxanthin, and lycopene remained almost unchanged, whereas retinol plasma concentrations increased slightly. By contrast, with the exception of elevated 13-cis-retinoic acid in one group (21.6 mg/d, water dispersible powder), the concentrations of all-trans-retinoic acid, and the oxo-derivatives or retinoic acid were not significantly affected by b-carotene supplementation. CONCLUSIONS: The results confirm that the relative bioavailability of beta-carotene depends largely on the source of b-carotene and demonstrate the superior bioavailability of beta-carotene powder in comparison to that in carrot juice.
Angiotensin II Type 1 receptor antagonists share most but not all of their pharmacological actions with angiotensin-converting enzyme inhibitors. The latter belong to standard heart failure therapy, with proven benefit in terms of morbidity and mortality. Promising data have been provided for angiotensin II Type 1 receptor antagonists in experimental models of heart failure. In patients with hypertension and those with diabetic nephropathy, favourable results have been observed with regards to blood pressure control, reversibility of structural changes or prevention of progression of disease. The currently available clinical trials in heart failure patients with angiotensin II Type 1 receptor antagonists suggest that they may be equivalent to angiotensin-converting enzyme inhibitors, but superiority has not been proven. There is no doubt about their effectiveness with regards to symptoms; however, their effect on hospitalisation and mortality is not unequivocally demonstrated. Further trials are warranted, particularly to define their role in comparison with and in addition to angiotensin-converting enzyme inhibitors and to further characterise heart failure patient populations who derive benefit from angiotensin II Type 1 receptor blockers above and beyond angiotensin-converting enzyme inhibitors, beta-blockers and spironolactone.