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Biomedical subjects

W Kirch

Publications and source records attributed to W Kirch.

At least 37 records · Page 2Linked to original sources

Hydrophilic interaction chromatography combined with tandem-mass spectrometry to determine six aminoglycosides in serum.

A specific and automated method was developed to quantitate the aminoglycosides amikacin, gentamicin, kanamycin, neomycin, paromomycin, and tobramycin simultaneously in human serum. Samples were prepared with an automated solid phase extraction (SPE). The hydrophilic interaction chromatography (HILIC) was used for separation of analytes from endogenous compounds and baseline separation. The aminoglycosides were detected with electrospray ionisation tandem mass spectrometry (ESI-MS-MS). Using a volume of 500 microl biological sample the lower limits of quantification were 100 ng/ml or better. The described HILIC-MS-MS method is suitable for therapeutic drug monitoring and for clinical and pharmcokinetical investigations of the aminoglycosides.

Aminoglycosides↗

[Arterial hypertension in obese patients. Rationale for a prospective medical care study in the family doctor's practice].

Patients with high blood pressure are often overweight or even obese. Conversely, some 43% of overweight and obese patients suffer from hypertension. Diabetes (16.7%), coronary heart disease (15.0%) and nephropathy (7.8%) are common additional findings. The cardiac risk in these patients is thus appreciably elevated. Currently, a prospective medical care study "Best practice with irbesartan in overweight and obese patients" (BIG) - is being conducted throughout Germany. In this study obese hypertensive patients of general practitioners are receiving the AT1 blocker irbesartan, as monotherapy or in fixed combination with the diuretic hydrochlorothiazide over a period of 3 months. Obese patients and nonobese patients are compared with regard to the following variables: drug utilization, blood pressure decrease, responder rates, normalization rates, decrease in the number of patients with (micro)albuminurea, changes in patient risk profile (e.g. after SCORE), and tolerability. The study is expected to provide new information on the efficacy, tolerability and safety of irbesartan in regard to pressure reduction and its protective effect on the kidneys and heart in overweight patients.

Albuminuria↗

[Epidemiology of attempted suicide using drugs. An inquiry from the Dresden University Clinic].

BACKGROUND AND OBJECTIVE: Little representative data of the epidemiology of attempted suicide exists in Germany. In this study the frequency of parasuicidal drug intoxication, the distribution of age and gender, as well as the kind and origin of used drugs were evaluated. Furthermore the knowledge about used drugs and possible adverse effects of a previously given medication were analysed. PATIENTS AND METHODS: Over a period of 2 years (January 1998-December 1999) 155 patients (41 males, 114 females, average age 40.5 years) with drug intoxication by attempted suicide were recruited at the University Hospital of Dresden, Germany, for further retrospective analysis. RESULTS: 74 % of these patients were women. Sedatives and hypnotics were most frequently used for parasuicide (44 %), followed by analgesics (18 %) and antidepressants (12 %). Benzodiazepines and benzodiazepine-agonists were the most commonly used drugs (32 %). Moreover, 80 % of all drugs used had been prescribed by physicians. Approximately half of the patients were well-informed about drugs taken. In 43 (47 %) of 92 patients with long-term medication an adverse effect was considered as a possible cause of the attempted suicide. CONCLUSION: Our data underline the importance of attempted suicide in view of the frequency of their use, the need of hospitalization, the required intensive care and possible relapses. Because the majority of drugs used were prescribed by physicians, before giving any medication to their possible suicidal use should be considered.

Adolescent↗

Determination of Tirofiban in human serum by liquid chromatography-tandem mass spectrometry.

A liquid chromatography-tandem mass spectrometric (LC-MS-MS) method with a rapid and simple sample preparation was developed and validated for the determination of Tirofiban in biological fluids. Tirofiban in serum samples was extracted and cleaned up by using an automated solid phase extraction method. An external calibration was used. The mass spectrometer was operated in the multiple reaction monitoring mode (MRM). A good linear response over the range of 2-200ng/ml was demonstrated. The accuracy for Tirofiban ranged from 94.8 to 110.8% within-day and from 103.0 to 104.7% between-day. The lower limit of quantification was 2ng/ml. This method is suitable for pharmacokinetic studies.

Chromatography, Liquid↗

Determination of neomycin by LC-tandem mass spectrometry using hydrophilic interaction chromatography.

A specific, and automated method was developed to quantitate neomycin in human serum. Samples were prepared with an automated solid phase extraction (SPE). The hydrophilic interaction chromatography (HILIC) was used for additional sample cleanup and baseline separation. The analyte neomycin was detected with electrospray ionisation tandem mass spectrometry (ESI-MS-MS). Using a volume of 500 microl biological sample the lower limit of quantification was 100 ng/ml. The described HILIC-MS-MS method is suitable for clinical and pharmcokinetical investigations of neomycin.

Chromatography, Liquid↗

Patterns of antihypertensive drug utilization in primary care.

BACKGROUND: In the treatment of hypertension, physicians' attitudes and practice patterns are receiving increased attention as contributors to poor blood pressure (BP) control. Thus, current use of antihypertensive drugs in primary care was analyzed and the association with selected physician and patient characteristics was assessed. METHODS: The Hypertension and Diabetes Risk Screening and Awareness (HYDRA) study is a cross-sectional point prevalence study of 45,125 primary care attendees recruited from a representative nationwide sample of 1912 primary care practices in Germany. Prescription frequencies of the various antihypertensive drugs in the individual patients were recorded by the physicians using standardized questionnaires. We assessed the association of patient variables [age, gender; co-morbidities such as diabetes, nephropathy or coronary heart disease (CHD)] and physician variables (general practitioner vs internist, guideline adherence, etc.) with drug treatment intensity and prescription patterns. RESULTS: Of all 43,549 patients for whom a physician diagnosis on hypertension or diabetes was available, 17,485 (40.1%) had hypertension. Of these hypertensive patients, 1647 (9.4%) received no treatment at all, 1191 (6.8%) received non-pharmacological measures only, and 14,647 (83.8%) were given one or more antihypertensive drugs. Drug treatment rates were lower in young patients (16-40 years: 57.4%). BP control was poor: 70.6% of all patients were not normalized, i.e., had BP >/=140/90 mmHg. Antihypertensive treatment was generally intensified with increasing age, or if complications or comorbidities were present. The use of the different drug classes was rather uniform across the various patient subgroups (e.g., by age and gender). Individualized treatment with regard to co-morbidities as recommended in guidelines was not the rule. Adherence to guidelines as self-reported by physicians as well as other physician characteristics (region, training etc.) did not result in more differentiated prescription pattern. CONCLUSIONS: Despite the broad armamentarium of drug treatment options, physicians in primary care did not treat hypertension aggressively enough. Treatment was only intensified at a late stage, after complications had occurred. Treatment should be more differentiated in terms of coexisting morbidities such as diabetes, nephropathy, or CHD.

Adolescent↗

[Psychopharmaceutical prescriptions to older people. A comparison between patients in aged- and nursing homes, outpatient treatment with nursing care and outpatients without nursing care].

To determine, whether age, sex, grade of need of care and living in nursing homes can influence prescribing behavior in elderly. In a retrospective and longitudinal study, the pattern of psychoactive drug prescriptions of nursing home residents was compared with non-institutionalized people with and without need of care. During 1999, the computerized files of 3592 people (> 60 years), insured by a health insurance fund (BKK) in Berlin, Germany, were obtained. Nursing home residents received significantly more prescriptions of psychoactive drugs than the others, especially more neuroleptics (40.1% versus 12.4% and 7.4%). Quality of prescriptions seemed to be higher in nursing homes (use of drugs with fewer side effects and less possible interactions), psychoactive drug prescriptions were given more frequently by psychiatrists and neurologists (37%). Non-institutionalized patients received them most from general practitioners (45%). Women received more prescriptions of psychoactive drugs than male patients. With rising grade of need of care, proportionately more patients received psychoactive drugs. The results of this study show some evidence of the lacking quality in the prescriptions of psychopharmaceuticals to the elderly.

Age Distribution↗

Recognition and management of overweight and obesity in primary care in Germany.

BACKGROUND: In contrast to the well-documented high prevalence of overweight and obesity in the general population, the prevalence, recognition rates and management by primary care physicians--as the core gatekeeper in the health care system--remains poorly studied. PURPOSE OF THE STUDY: To examine (1) the point prevalence of overweight (BMI 25.0-29.9 kg/m(2)) and obesity (BMI> or =30 kg/m(2)) in primary care patients, (2) prevalence patterns in patients with high-risk constellations (diabetes, hypertension, cardiovascular disease, etc.), (3) doctors' recognition and interventions, as well as patients' use and perceived effectiveness of weight-loss interventions and (4) factors associated with non-treatment. METHODS: Cross-sectional point prevalence study of 45 125 unselected consecutive primary care attendees recruited from a representative nationwide sample of 1912 primary care practices. MEASURES: (1) standardized clinical appraisal of each patient by the physician (diagnostic status and recognition, severity, comorbidity, current and past interventions). (2) Patient self-report questionnaire: height and weight, illness history, past and current treatments and their perceived effectiveness, health attitudes and behaviors. RESULTS: (1) In all, 37.9% of all primary care attendees were overweight, 19.4% obese. (2) Rates for overweight and obesity were highest in patients with diabetes (43.6 and 36.7%) and hypertension (46.1 and 31.3%), followed by patients with cardiovascular disorders. Rates of overweight/obesity increased steadily by the number of comorbid conditions. (3) Doctors' recognition of overweight (20-30%) and obesity (50-65%) was low, patients' actual use of weight control interventions even lower (past 12 months: 8-11%, lifetime: 32-39%). Patient success rates were quite limited. (4) Co- and multimorbidity in particular as well as other patient and illness variables were identified as predictors for recognition, but prediction of patients' actual use of weight loss interventions was limited. CONCLUSIONS: Primary care management of overweight and obesity is largely deficient, predominantly due to four interrelated factors: doctors' poor recognition of patients' weight status, doctors' inefficient efforts at intervention, patients' poor acceptance of such interventions and dissatisfaction with existing life-style modification strategies.

Age Distribution↗

The effects of moclobemide on autonomic and cognitive functions in healthy volunteers.

BACKGROUND: Moclobemide, a reversible and selective inhibitor of the MAO-A isoenzyme, is marketed as an antidepressant that lacks autonomic and cognitive side effects. However, only few and inconclusive quantitative data on the effects of moclobemide on autonomic and cognitive functions have been reported in the literature. Therefore, a double-blind, randomized, placebo-controlled crossover trial was performed. METHODS: Twelve healthy male volunteers (age 22-29 years) received orally 150 mg moclobemide b.i.d. and placebo for 14 days each. Heart rate variability (HRV) and skin conductance response (SCR) following sudden deep breath were employed as parameters for autonomic function. Quantitative EEG (qEEG) and psychometric tests served as parameters for cognitive function. Measurements were performed before the start of drug administration and repeatedly on the last treatment day. RESULTS: Parameters of HRV and SCR were not changed by multiple dosing with moclobemide (P > 0.05). Neither cognitive functions such as flicker fusion frequency, memory, choice reaction time, and psychomotor performance nor qEEG was significantly influenced, but subjective tiredness was decreased at all time points of measurement after multiple dosing with moclobemide (P < 0.05). CONCLUSIONS: In conclusion, moclobemide does not appear to influence autonomic functions or cognitive functions when given subchronically to healthy humans. In contrast, changes in subjective mood hint at a subtle activating effect.

Adult↗

The effect of irbesartan in reducing cardiovascular risk in hypertensive type 2 diabetic patients: an observational study in 16,600 patients in primary care.

OBJECTIVES: As arterial hypertension substantially increases the risk of premature death, cardiovascular disease and renal insufficiency in patients with type 2 diabetes, effective and safe antihypertensive therapy is of importance. Therefore, the effect of irbesartan as monotherapy, or in fixed combination with hydrochlorothiazide, on blood pressure, metabolic parameters and microalbuminuria and the safety and tolerability of the drug were assessed. RESEARCH DESIGN AND METHODS: Multicentric, prospective, open phase IV study over 3 months in 16,600 patients with the clinical diagnoses of hypertension and type 2 diabetes. Blood pressure was measured sphygmometrically and albuminuria was assessed with semi-quantitative urine dipsticks. MAIN OUTCOME MEASURES: Systolic (SBP) and diastolic (DBP) blood pressure reduction, proportion of patients with microalbuminuria and cardiovascular risk calculated based on the SCORE score, each after a follow-up of 3 months compared to baseline. Number and nature of adverse events (AEs). RESULTS: The sample consisted of 51.3% men, mean age was 62.2+/-10.7 years, 53.9% of patients were overweight and 26.4% were obese. Mean SBP/DBP decrease after 3 months was 22.3/11.2 mmHg. The BP lowering effect was similar in the analyses of various subgroups (according to age group, sex, presence of micro- or macrovascular complications). Irbesartan treatment reduced the percentage of patients with microalbuminuria from 45.6% to 30.6% at 3 months (32.9% relative reduction). Metabolic parameters (lipids, blood glucose, HbA1c) and weight were improved significantly or showed trends for improvement, respectively. The mean 10-year cardiovascular risk as calculated with the SCORE score was decreased from a baseline value of 9.8% to 5.7% (-58% relative reduction). Tolerability was excellent: only 0.3% experienced an AE. CONCLUSIONS: Treatment with irbesartan in patients with concomitant hypertension and type 2 diabetes led to large blood pressure reductions. In view of the renoprotective effect documented by the reduced rate of patients with albuminuria, and the improvement of further metabolic parameters, these changes translate into a reduction of cardiovascular risk.

Administration, Oral↗

[IRMA-pRAcs: irbesartan in the treatment of microalbuminuria and proteinuria in patients with type 2 diabetes and hypertension-prospective observational study involving 38,016 patients in the general practice setting].

BACKGROUND AND AIMS: In daily practice, nephropathy is diagnosed in a high percentage of type 2 diabetics, including those in whom blood pressure is well controlled. The aim of the present study was to reduce albuminuria in these patients by changing over antihypertensive treatment to the AT, blocker irbesartan. 9,838 general practitioners recruited a total of 38,016 type 2 diabetics aged at least 18 years to an open observational study: In the majority of cases, current antihyprertensive treatment was discontinued and patients given 300 mg (a small percentage received 150 mg or 75 mg) irbesartan, either as monotherapy or in combination with 12.5 mg hydrochlorothiazide (HCT). The primary target outcome for efficacy was the 6-months normalization rate in patients with microalbuminuria or proteinuria; secondary target parameters included the change in protein excretion (grades: negative, 20 mg, 50 mg, 100 mg), normalisation of the systolic or diastolic blood pressure, and responder and blood pressure normalization rates. The target criterion for tolerability was the number of patients with adverse events (AE). RESULTS: 46% of the patients were controlled with 300 mg irbesartan alone, and 40% with irbesartan in combination with HCT. Albumin excretion normalized in 60.5% of the patients, improved by at least one grade in 81.9%, remained unchanged in 17.5%, and increased in 0.7% of the cases. The beneficial response was found to be independent ofthe type of prior antihypertensive treatment (including ACE-inhibitors) and was also seen in normotensive patients. Only 0.4 % of the patients reported AEs. CONCLUSION: In type 2 diabetics, treatment with 300 mg irbesartan administered alone or in combination with 12.5 mg HCT produced a pronounced nephroprotective effect.

Adolescent↗

[Aim, design and methods of the "Hypertension and diabetes screening and awareness" -- (HYDRA) study].

Aim of the study is a comprehensive clinical-epidemiological description of the prevalence of arterial hypertension and diabetes among primary care patients along with an assessment of doctor's recognition rates and prescription behaviour. The paper describes methods and design of the study and provides background information on the sampling process, instruments used as well as characteristics of doctors and patients. The study is based on a nationally representative sample of 1,912 primary care doctors and 45,000 patients that attended the doctors' office on the target days. The patients were also characterized by laboratory tests. The first stage of study consisted of a comprehensive description of the doctors' characteristics in terms of psychosocial, qualification- and provider aspects as well as attitudes towards hypertension and diabetes and their management. In the second stage all patients completed a questionnaire to describe their health behaviour and attitudes as well as the treatment history and therapy. In the third stage all patients were characterized by their doctors in terms of their diagnostic status and their past and current interventions.

Adolescent↗

[Management of diabetes and hypertension: how do primary care physicians judge their performance?].

With regard to the management of hypertension and diabetes, HYDRA reveals that doctors report multiple problems in their everyday practice. Being confronted with an average of 73 patients a day, with almost every second having either diabetes or hypertension, frequently associated with multiple comorbid conditions, the core obstacle is the time factor. Doctors do not have sufficient time to perform diagnostic tests and especially no time for non-drug interventions of any type. Further available treatment guidelines are only used in 1 out of 2 doctors. Further they seem not to affect doctors performance significantly.

Adult↗