Evaluation of the matrix effect of different sample matrices for 33 pharmaceuticals by post-column infusion.

Matrix effects that occur during quantitative measurement by liquid chromatography mass spectrometry specifically when using electrospray ionization are a widely recognized phenomenon. Sample matrix compounds affect the ionization process of the target analytes, lead to a low signal response, and flawed analytical results. How these matrix compounds directly influence the ionization process has not yet been completely understood. In the present study, we determined the matrix effect for 33 pharmaceutical substances in sample extracts of urine, plasma and wastewater. Most of the investigated substances were subject to a signal suppression effect. Only for a small subset of the compounds we detected a signal enhancement effect. We investigated the matrix effect profiles in detail to disentangle the influence of different matrices and to correlate the impact of specific components and groups of the analyzed extract in suppressing or enhancing effects in the profile. Most signal suppression effects were detected in the first half of the chromatographic run-time for the matrix extracts of urine and wastewater. The observed effects are caused by high mass flow of salts and other diverse matrix components that were contained in high concentrations in those biological matrices. We also found signal suppression in the matrix effect profile of plasma samples over a wide time range during the chromatographic separation that were associated with a high content of triglycerides of diverse carbohydrate chain lengths. Here, we provide a broader picture of how 33 substances were influenced during analysis. Our results imply that a high number of the investigated substances had comparable effects of matrix compounds, despite differences in their chemical structure.

[Health care of geriatric patients with urinary incontinence]. / Gesundheitsversorgung bei Harninkontinenz im Alter.

Urinary incontinence occurs frequently in geriatric patients. In the doctor's practice, the symptoms are often not mentioned by the patients; this may lead to loss of autonomy and social isolation. A screening for urinary incontinence should therefore be part of each geriatric assessment. In the presence of urinary incontinence, several treatment options are available, which need to be tailored according to the individual capabilities (mobility, motivation and cognitive performance) of the patient. Non-pharmacological treatment options, such as behavior modification, toilet training and pelvic floor training, should be exploited before any pharmacotherapy commences. If the pharmacological treatment involves the use of anticholinergic agents, the cognitive performance should be monitored. An interdisciplinary collaboration is a prerequisite for the optimized treatment and adequate health care of geriatric patients with urinary incontinence.

Acceptance factors of mobile apps for diabetes by patients aged 50 or older: a qualitative study.

BACKGROUND: Mobile apps for people with diabetes offer great potential to support therapy management, increase therapy adherence, and reduce the probability of the occurrence of accompanying and secondary diseases. However, they are rarely used by elderly patients due to a lack of acceptance. OBJECTIVE: We investigated the question "Which factors influence the acceptance of diabetes apps among patients aged 50 or older?" Particular emphasis was placed on the current use of mobile devices/apps, acceptance-promoting/-inhibiting factors, features of a helpful diabetes app, and contact persons for technical questions. This qualitative study was the third of three substudies investigating factors influencing acceptance of diabetes apps among patients aged 50 or older. METHODS: Guided interviews were chosen in order to get a comprehensive insight into the subjective perspective of elderly diabetes patients. At the end of each interview, the patients tested two existing diabetes apps to reveal obstacles in (first) use. RESULTS: Altogether, 32 patients with diabetes were interviewed. The mean age was 68.8 years (SD 8.2). Of 32 participants, 15 (47%) knew apps, however only 2 (6%) had already used a diabetes app within their therapy. The reasons reported for being against the use of apps were a lack of additional benefits (4/8, 50%) compared to current therapy management, a lack of interoperability with other devices/apps (1/8, 12%), and no joy of use (1/8, 12%). The app test revealed the following main difficulties in use: nonintuitive understanding of the functionality of the apps (26/29, 90%), nonintuitive understanding of the menu navigation/labeling (19/29, 66%), font sizes and representations that were too small (14/29, 48%), and difficulties in recognizing and pressing touch-sensitive areas (14/29, 48%). Furthermore, the patients felt the apps lacked individually important functions (11/29, 38%), or felt the functions that were offered were unnecessary for their own therapy needs (10/29, 34%). The most important contents of a helpful diabetes app were reported as the ability to add remarks to measured values (9/28, 32%), the definition of thresholds for blood glucose values and highlighting deviating values (7/28, 25%), and a reminder feature for measurement/medication (7/28, 25%). The most important contact persons for technical questions were family members (19/31, 61%). CONCLUSIONS: A lack of additional benefits and ease of use emerged as the key factors for the acceptance of diabetes apps among patients aged 50 or older. Furthermore, it has been shown that the needs of the investigated target group are highly heterogeneous due to varying previous knowledge, age, type of diabetes, and therapy. Therefore, a helpful diabetes app should be individually adaptable. Personal contact persons, especially during the initial phase of use, are of utmost importance to reduce the fear of data loss or erroneous data input, and to raise acceptance among this target group.

Statin treatment in hypercholesterolemic men does not attenuate angiotensin II-induced venoconstriction.

UNLABELLED: Experimental studies suggested that statins attenuate vascular AT1 receptor responsiveness. Moreover, the augmented excessive pressor response to systemic angiotensin II infusions in hypercholesterolemic patients was normalized with statin treatment. In 12 hypercholesterolemic patients, we tested the hypothesis that statin treatment attenuates angiotensin II-mediated vasoconstriction in hand veins assessed by a linear variable differential transducer. Subjects ingested daily doses of either atorvastatin (40 mg) or positive control irbesartan (150 mg) for 30 days in a randomized and cross-over fashion. Ang II-induced venoconstriction at minute 4 averaged 59%±10% before and 28%±9% after irbesartan (mean ± SEM; P<0.05) compared to 65%±11% before and 73%±11% after 30 days of atorvastatin treatment. Plasma angiotensin levels increased significantly after irbesartan treatment (Ang II: 17±22 before vs 52±40 pg/mL after [p = 0.048]; Ang-(1-7): 18±10 before vs 37±14 pg/mL after [p = 0.002]) compared to atorvastatin treatment (Ang II: 9±4 vs 11±10 pg/mL [p = 0.40]; Ang-(1-7): 24±9 vs 32±8 pg/mL [p = 0.023]). Our study suggests that statin treatment does not elicit major changes in angiotensin II-mediated venoconstriction or in circulating angiotensin II levels whereas angiotensin-(1-7) levels increased modestly. The discrepancy between local vascular and systemic angiotensin II responses might suggest that statin treatment interferes with blood pressure buffering reflexes. TRIAL REGISTRATION: ClinicalTrials.gov NCT00154024.

Simultaneous determination of most prescribed antibiotics in multiple urban wastewater by SPE-LC-MS/MS.

A rapid analytical method was developed for the application of a long-term monitoring (>one year) of the most prescribed and often in hospitals used antibiotics in diverse wastewaters of an urban sewage treatment plant (STP). Additionally to the selected multi-class antibiotics amoxicillin, penicillin V and piperacillin (penicillins), cefotaxime and cefuroxime (cephalosporins), azithromycin, clarithromycin and roxithromycin (macrolids), ciprofloxacin and levofloxacin-ofloxacin (fluoroquinolones), clindamycin (lincosamide), doxycycline (tetracycline), sulfamethoxazole (sulfonamide) and trimethoprim (dihydrofolate reductase inhibitor), the bioactive metabolite clindamycin-sulfoxide, the reserve antibiotic vancomycin (glycopeptide) and as tracer of the STP the anticonvulsant carbamazepine and the antifungal fluconazole were involved. The analytical method combines a low-sample-volume solid phase extraction (SPE), followed by a chromatographic separation using a reversed phase (RP) and hydrophilic interaction liquid chromatography (HILIC) technique, respectively, coupled to a triple quadrupole mass spectrometer. Detection was performed with multiple reaction monitoring (MRM) measured with positive electrospray ionization (ESI+). The extraction efficiency of different SPE cartridges and optimized pH-values of the preparation procedure were tested. Finally, the extraction of antibiotics was realized with the Oasis HLB cartridge and a pH adjustment at 3.5. An external calibration curve in diluted blank urine was used for quality control of the sample set of daily composite samples of the STP for the duration of one year monitoring. The squared coefficient of determination (r(2)) in the concentration range (20-20,000ng/L or 100-100,000ng/L) of the calibration curves for the method was higher than 0.99 for all determined substances. The limit of quantification (LoQ) ranged between 0.8ng/L (azithromycin) and 245.1ng/L (vancomycin). Furthermore, a standard addition was used for quantification in wastewater samples. The process efficiencies ranged from 20% (doxycycline) to 134% (cefuroxime) in influent samples and from 31% (doxycycline) to 171% (cefuroxime) in effluent samples of the STP. All selected substances have been found in wastewater samples. Cefuroxime, doxycycline, levofloxacin, piperacillin, sulfamethoxazole and carbamazepine showed highest concentrations up to 6.2µg/L.

Mobile applications for diabetics: a systematic review and expert-based usability evaluation considering the special requirements of diabetes patients age 50 years or older.

BACKGROUND: A multitude of mhealth (mobile health) apps have been developed in recent years to support effective self-management of patients with diabetes mellitus type 1 or 2. OBJECTIVE: We carried out a systematic review of all currently available diabetes apps for the operating systems iOS and Android. We considered the number of newly released diabetes apps, range of functions, target user groups, languages, acquisition costs, user ratings, available interfaces, and the connection between acquisition costs and user ratings. Additionally, we examined whether the available applications serve the special needs of diabetes patients aged 50 or older by performing an expert-based usability evaluation. METHODS: We identified relevant keywords, comparative categories, and their specifications. Subsequently, we performed the app review based on the information given in the Google Play Store, the Apple App Store, and the apps themselves. In addition, we carried out an expert-based usability evaluation based on a representative 10% sample of diabetes apps. RESULTS: In total, we analyzed 656 apps finding that 355 (54.1%) offered just one function and 348 (53.0%) provided a documentation function. The dominating app language was English (85.4%, 560/656), patients represented the main user group (96.0%, 630/656), and the analysis of the costs revealed a trend toward free apps (53.7%, 352/656). The median price of paid apps was €1.90. The average user rating was 3.6 stars (maximum 5). Our analyses indicated no clear differences in the user rating between free and paid apps. Only 30 (4.6%) of the 656 available diabetes apps offered an interface to a measurement device. We evaluated 66 apps within the usability evaluation. On average, apps were rated best regarding the criterion "comprehensibility" (4.0 out of 5.0), while showing a lack of "fault tolerance" (2.8 out of 5.0). Of the 66 apps, 48 (72.7%) offered the ability to read the screen content aloud. The number of functions was significantly negative correlated with usability. The presence of documentation and analysis functions reduced the usability score significantly by 0.36 and 0.21 points. CONCLUSIONS: A vast number of diabetes apps already exist, but the majority offer similar functionalities and combine only one to two functions in one app. Patients and physicians alike should be involved in the app development process to a greater extent. We expect that the data transmission of health parameters to physicians will gain more importance in future applications. The usability of diabetes apps for patients aged 50 or older was moderate to good. But this result applied mainly to apps offering a small range of functions. Multifunctional apps performed considerably worse in terms of usability. Moreover, the presence of a documentation or analysis function resulted in significantly lower usability scores. The operability of accessibility features for diabetes apps was quite limited, except for the feature "screen reader".

Management of patients with atrial fibrillation by primary-care physicians in Germany: 1-year results of the ATRIUM registry.

BACKGROUND: Patients with atrial fibrillation (AF) in Germany are often managed jointly by primary-care physicians in cooperation with cardiologists. We aimed to investigate the management and 1-year outcomes of AF patients in this setting. HYPOTHESIS: We set out to describe the current management of AF patients in primary care settings in Germany. METHODS: Observational registry with 1-year follow-up, performed by a representative, randomly selected sample of 781 primary-care physicians in Germany. RESULTS: Of 3781 patients with electrocardiographically documented AF, 3163 patients (age 71.9 ± 9.2 years, 57.9% males) were followed for 1 year; 28.4% had paroxysmal, 27.0% persistent, and 43.3% permanent AF. Comorbid conditions were common (mean CHA2 DS2-VASc score 3. 8 ± 1.7). Rhythm-control therapy was used in 16.4%. Although oral anticoagulation was often used (82.7% at baseline), stroke rate during follow-up was high (2.7% stroke, 3.0% transient ischemic attack). Despite a long duration of AF (mean duration 61 months at enrollment), 18.5% of patients were hospitalized during the 1-year follow-up. CONCLUSIONS: In this unselected group of patients with long-standing AF managed in primary care, hospitalizations and cardiovascular complications including strokes are frequent, illustrating the need to improve management of AF patients.

Determination of clindamycin and its metabolite clindamycin sulfoxide in diverse sewage samples.

In a research project on risk management of harmful substances in water cycles, clindamycin and 12 further antibiotics were determined in different sewage samples. In contrast to other antibiotics, an increase of the clindamycin concentration in the final effluent in comparison to the influent of the sewage treatment plant (STP) was observed. A back transformation from the main metabolite clindamycin sulfoxide to clindamycin during the denitrification process has been discussed. Therefore, the concentration of this metabolite was measured additionally. Clindamycin sulfoxide was stable in the STP and the assumption of back transformation of the metabolite to clindamycin was confuted. To explain the increasing clindamycin concentration in the STP, the ratio of clindamycin sulfoxide to clindamycin was observed. The ratio increased in dry spells with concentrated samples and with long dwell time in the sewer system. A short hydraulic retention in waste water system and diluted samples in periods of extreme rainfall lead to a lower ratio of clindamycin sulfoxide to clindamycin concentration. A plausible explanation of this behavior could be that clindamycin was adsorbed strongly to a component of the sewage during this long residence time and in the STP, clindamycin was released. In the common sample preparation in the lab, clindamycin was not released. Measurements of clindamycin and clindamycin sulfoxide in the influent and effluent of STP is advised for sewage monitoring.

Disparities of conjugating protective enzyme activities in the colon of patients with adenomas and carcinomas.

AIM: To investigate the metabolic enzymatic capacity of the colon mucosa to detoxify noxious carcinogenic compounds. METHODS: We investigated the activity of 2 conjugating enzymes-the microsomal uridine glucuronosyltransferase (UGT) and the cytosomal glutathione S-transferase (GST) in the uninvolved mucosa of the colon transversum and sigmoideum in patients with adenomatous polyps and colorectal cancer. Biopsies were taken from the mucosa during colonoscopies which were done for clinical (diagnostic) reasons. After storage, the biopsy material was homogenized and after differential centrifugation the enzyme assays were performed with 4-nitrophenol (UGT) and 1-chloro 2,4-dinitrobenzene (GST) as substrates. RESULTS: About 48 patients were included of which 28 had adenomas and 20 had colorectal carcinomas confirmed by histopathology. Enzyme activities were expressed as nmol/mg per minute protein for the GST and as pmol/mg per minute protein for the UGT. Analysis of variance (F-test) indicated that both enzymes were more widely distributed in adenoma than in cancer patients. The means ± SD were smaller for cancer patients: GST for adenomas 268 ± 152 vs 241 ± 69 for carcinomas and UGT for adenomas 197 ± 200 vs 150 ± 86 for carcinomas. CONCLUSION: Compared to patients with adenomatous colon polyps those with colorectal carcinoma exhibited a lower capacity of detoxifying enzyme metabolism and their activities clustered over a smaller range.

Gender differences in patients with atrial fibrillation.

AIMS: We aimed to compare gender differences with respect to presentation of consecutive ambulatory patients with atrial fibrillation (AF), management of their disease, and outcomes. METHODS: Post-hoc analysis of an observational (non-interventional) study performed by 616 office- and hospital-based cardiologists in Germany. Consecutive (mainly ambulatory) patients with Electrocardiography (ECG) -confirmed AF and available data from baseline (BL) and two follow-up visits at 6 and 12 months were assessed. RESULTS: A total of 2,742 patients (62.8% males, mean age 67.5 years; 37.2% women, mean age 71.2 years) were analysed. Women had more frequently paroxysmal and less frequently permanent AF. Quality of life scores were slightly worse in women compared to men, for all types of AF. For class III anti-arrhythmic drugs at baseline (more frequent in men), and for digitalis (less frequent in men at BL and 1 year) statistically significant differences were noted. Oral anti-coagulation (OAC) without anti-platelet drugs was given in 67.9% at BL and in 62.7% at 1 year (no differences between genders). During follow-up, drug conversions in men/women were reported in 12.3%/14.9% (p=0.054), and electrical conversions in 14.6%/11.7% (p=0.03). Hospitalisations occurred in 25.9% and strokes in 3.5%. Patients with higher CHA2DS2-VASc scores had increased stroke rates (0, 1 and ≥2 points: 0.0, 1.5 and 3.9%, respectively; with no significant gender differences). CONCLUSION: In everyday management of patients with AF, there were no differences in treatment and major outcomes, in particular stroke, between women and men. This finding is opposed to earlier studies reporting OAC undertreatment of women and higher stroke rates.

Evaluation of a program of integrated care to reduce recurrent osteoporotic fractures.

PURPOSE: To evaluate the outcomes of patients participating in a program of integrated care for osteoporosis in terms of medication supply, fracture incidence and expenses. METHODS: Outcomes were assessed from secondary data provided by the AOK PLUS health insurance for 2455 participants of the program and the same number of matched controls who were also diagnosed with osteoporosis but did not participate in the program. Supply with Calcium and Vitamin D, antiresorptive agents and analgesics was assessed by defined daily doses. Osteoporotic fractures were identified by hospitalization data. Costs for fracture treatment, medication supply and additional expenses of the program were also included in the dataset. RESULTS: Patients enrolled in the program of integrated care received significantly more medication to treat osteoporosis than controls. There was no significant reduction in fracture incidence among participants of integrated care, but a reduced need of analgesics was noted. Additional costs for patients enrolled in the program were caused by a higher number of drug prescriptions, higher costs for stationary treatment and additional expenses for program related care and diagnostics. CONCLUSIONS: The program of integrated care was not found to be effective in reducing recurrent fractures. Cost effectiveness defined as a reduced rate of fractures in integrated care patients could not be shown by the assessed outcome measures. This missing reduction in fracture incidence may be explained by a non-sufficient improvement - compared to a placebo-controlled clinical trial - in medication supply and non-comparability of our real-world patient population with highly controlled clinical trial participants.

Treatment of neurological autoimmune diseases with immunoglobulins: first insights from the prospective SIGNS registry.

PURPOSE: Several immunoglobulin (IG) preparations have been approved for the immunomodulatory treatment of the neurological autoimmune diseases (AID) Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathy (CIDP), and multifocal motor neuropathy (MMN). Although efficacy has been proven in randomised clinical trials, long-term outcome data on drug utilization, effectiveness, tolerability, health related quality of life, and economic variables are lacking. METHODS: In the prospective, observational internet-based SIGNS registry, patients of all age groups are eligible if they have received or are scheduled for IG therapy for neurological AID or primary or severe secondary immunodeficiency. RESULTS: Of the 306 patients currently included in the database (1 November 2011), 51 have neurological AID (27 males; mean age 56 ± 15 years): 21 CIDP, 7 MMN, 11 multiple sclerosis (MS), 6 myasthenia gravis, 2 myositis, 4 others (no cases of GBS). Mean duration of disease since first symptoms was 7.8 years, and disease duration since diagnosis was 5.9 years. Eight different IG preparations have been reported as current therapy. According to SF-36, patients' quality of life is substantially impaired. CONCLUSIONS: Present data indicate some off-label use of IG (e.g. in MS) in patients with neurological AID. Quality of life in these patients is substantially compromised. Increasing patient numbers and extended follow-up periods will provide data on treatment concepts and disease development in AID patients.

Atrial fibrillation management, outcomes and predictors of stable disease in daily practice: prospective non-interventional study.

BACKGROUND: We aimed to describe the current management of patients with atrial fibrillation (AF) by cardiologists, and to identify predicting factors for a stable disease course. METHODS: 2753 consecutive patients with ECG-confirmed AF in the previous 12 months were documented in a 1-year observational (non-interventional) study from 616 centers. Stable disease was defined as having neither AF related intervention nor change in antiarrhythmic therapy in the previous 12 months. Stepwise selection of parameters for multivariate regression was used to identify factors for stable AF. RESULTS: At baseline, paroxysmal AF was reported in 33.5%, persistent in 26.7%, and permanent in 39.7%; rate control alone was the prevailing antiarrhythmic strategy (64.2%). Drugs for thromboembolic prevention were administered in 93.8%, with a clear predominance of oral anticoagulants (OAC), alone or in combination with antiplatelet drugs. Electrical or pharmacological conversions were reported in 23.6%. A total of 96 (3.5%) patients in the total cohort experienced stroke, 72 patients (2.6%) TIA, and 24 (0.9%) arterial embolism. 26% were hospitalized during follow-up (0.4 events per patient), and 9.4% developed incident heart failure (42% prevalence at follow-up). The rate of stable patients was 43.4%. In the multivariate model male gender, history of stroke, and permanent (vs. persistent) AF were associated with stable disease. Conversely, the factors chronic heart failure, impaired left ventricular function, rhythm-control (vs. other), OAC and antiplatelet therapy were significantly correlated with unstable disease. CONCLUSIONS: The relatively low proportion of stable patients and in particular, the high hospitalization and stroke rate indicate difficulties in everyday management of patients with AF.

Determination of the novel melatonin agonist Neu-P11 in plasma samples by liquid chromatography-tandem mass spectrometry.

Melatonin is a major chronobiological regulator involved in circadian phasing, sleep, and numerous other functions. The novel melatonin agonist Neu-P11 is used in treatment of physiological insomnia. In animal studies Neu-P11 showed sleep-promoting effect. In a phase 1 study Neu-P11 was administered to cohorts of healthy young male volunteers in an ascending single dose study. Up to now no method for measurement of the new drug in human plasma was described and validated. The aim of this study was to develop a suitable analytical procedure. With solid phase extraction (SPE) for sample preparation and liquid chromatography tandem mass spectrometry (LC/MS/MS) a sensitive method with a lower limit of quantification of 0.39 ng/ml was found. For SPE samples were put into Strada C18 cartridges and automatically extracted by a Gilson Automatic Sample Processor ASPEC XL. The HPLC was carried out with a Purospher C18 column and mobile phase gradient with acetonitrile, and ammonium acetate. The precision ranged from 0.4% to 9.5%. The deviation of the measured from the true value, of the standard samples and QCSs was lower than 10%. The method was specific, precise and accurate and the analyte was stable under the conditions of measurement. Results show that the method is suitable for the quantification of NeuP11 in human plasma after a single dose of 5, 20, 50 or 200mg.

Pharmaco-economic impact of demographic change on pharmaceutical expenses in Germany and France.

BACKGROUND: Most European health care systems are suffering from the impact of demographic change. In short, aging of society is leading to higher costs of treatment per capita, while reproduction rates below 2.1 children per woman lead to a reduced number of younger people to provide for the necessary contributions into the health insurance system.This research paper addresses the questions what impact the demographic development will have on one particular spending area, what are pharmaceutical expenditure in two of Europe's largest health care systems, Germany and France, and what the implications are for pharmaceutical companies. METHODS: The research is based on publicly available data from German and French health ministries, the OECD, and institutes which focus on projection of demographic development in those countries. In a first step, data was clustered into age groups, and average spending on pharmaceuticals was allocated to that. In the second step, these figures were extrapolated, based on the projected change in the demographic structure of the countries from 2004 until 2050. This leads to a deeper understanding of demand for pharmaceutical products in the future due to the demographic development as a single driving factor. RESULTS: - Pharmaceutical expenses per head (patient) will grow only slightly until 2050 (0.5% p.a. in both countries). - Demographic change alone only provides for a slowly growing market for pharmaceutical companies both in Germany and in France, but for a relevant change in the consumption mix of pharmaceutical products, based on a shift of relevance of different age groups. CONCLUSIONS: Despite demographic changes pharmaceutical expenses per head (patient) and the overall pharmaceutical markets will grow only slightly until 2050 in Germany as well as in France. Nevertheless, the aging of society implies different challenges for pharmaceutical companies and also for the health care system. Companies have to cope with the shift of relevance of different age groups and within the health care system new options for financing the slowly growing expenses have to be found.

Validation of a transparent decision model to rate drug interactions.

BACKGROUND: Multiple databases provide ratings of drug-drug interactions. The ratings are often based on different criteria and lack background information on the decision making process. User acceptance of rating systems could be improved by providing a transparent decision path for each category. METHODS: We rated 200 randomly selected potential drug-drug interactions by a transparent decision model developed by our team. The cases were generated from ward round observations and physicians' queries from an outpatient setting. We compared our ratings to those assigned by a senior clinical pharmacologist and by a standard interaction database, and thus validated the model. RESULTS: The decision model rated consistently with the standard database and the pharmacologist in 94 and 156 cases, respectively. In two cases the model decision required correction. Following removal of systematic model construction differences, the DM was fully consistent with other rating systems. CONCLUSION: The decision model reproducibly rates interactions and elucidates systematic differences. We propose to supply validated decision paths alongside the interaction rating to improve comprehensibility and to enable physicians to interpret the ratings in a clinical context.

Potentially inappropriate prescribing for elderly outpatients in Germany: a retrospective claims data analysis.

OBJECTIVE: To quantify the frequency of potentially inappropriate medication (PIM) prescribing for outpatients aged 65 years and older using claims data of a German statutory health insurance. METHODS: Based on the 2002 Beers criteria for PIM use, a retrospective evaluation of drug prescription data in outpatient care was conducted for the years 2003 and 2004 using data from a German statutory health insurance (AOK) in the area of Saxony. The study was limited to those drugs classified as being potentially inappropriate according to the criteria independent of existing medical conditions and without any restrictions concerning dosage or duration of use, because this information was not available from the data. RESULTS: In 2003, 3.3% (408,375) of all 12,513,584 drug prescriptions for patients 65 years and older which were analyzed included a PIM from the Beers list. In 2004, it was 2.9% (297,524) of 10,126,809 (p < 0.001). The most frequently prescribed PIMs were short-acting nifedipine (13.4%), indomethacin (12.3%) and diazepam (11.8%) in 2003, and diazepam (14.6%) followed by indomethacin (13.7%) and doxazosin (10.9%) in 2004. 21.7% (119,482) and 18.2% (98,465) of patients 65 years or older received at least one prescription of a PIM in 2003 and 2004, respectively (p < 0.001). In a multivariate logistic regression model female gender and a higher number of prescribed drugs were significantly associated with an increased frequency of receiving a PIM in both years. CONCLUSIONS: In our study, approximately every 5th older patient was prescribed at least one PIM. For the future an ongoing update of the Beers criteria to further include newer agents and an adaptation to the different situation in European countries is desirable.

Influence of a fat-rich meal on bioavailability of extended-release and immediate-release propiverine.

The muscarinic receptor antagonist propiverine is unique insofar as extended-release (ER) tablets are of higher bioavailability than immediate-release (IR) tablets; this is caused by lower "first-pass" elimination of propiverine via CYP3A4 and efflux transporters in the distal small intestine and colon. Food may influence gastrointestinal transiting and, in turn, may affect regional absorption of propiverine IR and ER. Therefore, food effects on disposition of 30 mg IR and 45 mg ER were measured in a randomized, open, 4-period interaction study in 24 healthy participants. In fasting participants, ER had higher bioavailability than IR (F(rel) = 169%, P = .03). Fat-rich meal did not change the disposition of ER markedly (AUC(0-∞) ratio, 1.00 [90% confidence interval (CI), 0.90-1.11], C(max) ratio, 0.97 [0.87-1.09]). However, C(max) and renal A(e) of the major N-oxidized metabolite (M-5) significantly increased, whereas t(1/2) decreased. By eating a fat-rich meal before administration, the differences in absorption of IR and ER were nearly abolished (AUC(0-∞) ratio for propiverine, 1.12 [90% CI, 0.95-1.33]; AUC(0-∞) ratio for M-5, 0.89 [0.82-0.95]). In conclusion, propiverine ER has higher bioavailability than IR and no positive food effect because it reaches, independently of food, intestinal absorption areas with lower metabolism and efflux transport, which results in constant absorption rates.