Update zum Therapeutic Drug Monitoring und zu pharmakogenetischen Untersuchungen zur Optimierung der Therapie mit Psychopharmaka

Das Therapeutic Drug Monitoring von Psychopharmaka wird in zahlreichen Laboratorien immer häufiger durchgeführt, ebenso wie pharmakogenetische Untersuchungen. In diesem Übersichtsartikel wurde die dazugehörige Literatur aus den Jahren 2011 und 2012 zusammengefasst. Die Guidelines der AGNP enthalten alle wichtigen Informationen, die notwendig sind, um Konzentrationen von Psychopharmaka richtig zu interpretieren. Die Bestimmung von Serotonin im Urin könnte ein Marker zur Beurteilung des Therapieerfolgs von Antidepressiva darstellen. Mit Hilfe der Positronen-Emissions-Tomographie konnten Korrelationen zwischen der Belegung der Zielrezeptoren im Gehirn und der Medikamentenkonzentration ermittelt werden. Der Einfluss des Alters auf die Medikamentenkonzentrationen wurde kontrovers beschrieben, wohingegen Frauen in allen Arbeiten bei einigen Antidepressiva einen verlangsamten Metabolismus und erhöhte Serumkonzentrationen aufwiesen. In mehreren Publikationen wurden Multianalytenverfahren für die Bestimmung von Psychopharmaka beschrieben, die trotz unterschiedlicher Methoden sehr gute Validierungsresultate aufwiesen. Bei allen Methoden gibt es einige Substanzen, deren Validationsresultate nur knapp genügten, was auf die Tatsache zurückgeführt werden muss, dass bei Multianalytenverfahren nicht alle Analyten optimal nachgewiesen werden können. Pharmakogenetische Untersuchungen haben noch keinen festen Platz bei der Verordnung von Psychopharmaka. Dies beruht unter anderem auf dem Fehlen von Evidenz-basierten Daten aus großen randomisierten Studien und dem Fehlen von entsprechend standardisierten analytischen Methoden, die die gesamte genetische Variabilität nachweisen könne

Laboratory diagnostics in acute poisoning: critical overview

Laboratory diagnostics play an important role in the treatment of patients with acute poisoning. The classical clinical chemistry and hematology tests help initiate supportive treatment, and specialized methods enable elucidation of the poisons involved. In this context, two different analytical approaches are used: the direct quantification of a potentially involved compound or screening procedures looking either for a distinct drug class or a wide variety of different compounds. The most common tests are immunoassays, which have the advantage of being fast and highly automated. These assays are available for the substances which are often involved in intoxications. The other analytical technique which is widely used is hyphenated chromatography consisting of either high-performance liquid chromatography or gas chromatography as chromatographic systems and detection with a diode-array or mass spectrometer. Whereas gas chromatography mass spectrometry screening procedures have been known for a long time, liquid chromatography mass spectrometry screening methods are now developed by different research groups and still need to prove their reliability. In this review, the different analytical technologies and their application will be discussed. Clin Chem Lab Med 2010;48:1381-

Phosphate concentration in ophthalmic corticoid preparations

Background: Topical preparations, high in phosphate, may cause calcification when used on a damaged corneal surface. The knowledge of the phosphate concentration in medications helps to prevent corneal calcifications. Our study gives an overview of the amount of phosphate contained in ophthalmic corticoid preparations. Methods: Samples of 38 commercially available corticoid preparations were tested. The quantification of phosphate was performed using the molybdate method on a Modular P autoanalyzer. Results: 18 of 38 preparations (47%) had a phosphate concentration above physiological levels (>1.45mmol/l). It varied greatly, and ranged from less than 0.1mmol/l (18 preparations) to 62.6mmol/l. The corticoids that were tested included betamethasone sodium phosphate (18.3-35.5mmol/l), dexamethasone (0.1-17.6mmol/l), dexamethasone sodium phosphate (<0.1-62.6mmol/l), fluorometholone (<0.1-22.5mmol/l), and prednisolone acetate (<0.1-0.5mmol/l). Conclusions: The phosphate concentration in corticoid-phosphate formulations varies greatly, and is mainly determined by the chosen buffer. The prednisolone acetate preparations showed physiological phosphate concentrations. For a treatment on a damaged corneal surface, preparations with physiological phosphate concentrations should be use

Can Conservation and Profits Co-Exist?: The Case of Lion Hunting

Resource /Energy Economics and Policy,

Diagnostic efficiency of different amphetamine screening tests - the search for an optimal cutoff

Increased use of designer drugs (amphetamines and amphetamine-like substances) raises the need for fast screening tests in urine in clinical settings, workplace and drug rehabilitation. Immunological assays currently used are subject to unwanted crossreactivities, partly depending on the cutoff concentrations used. The values recommended in Europe and the USA are 500 and 1000 ng/ml, respectively. In Switzerland, the recommended concentration of 300 ng/ml results in a high rate of false-positive urine samples and expensive, time-consuming confirmation testing. Using the Abbott Axsym analyzer, we found numerous false positives from patients in rehabilitation centers due to concomitant medication. Therefore, the diagnostic sensitivity and specificity of the Abbott test at different cutoff concentrations and the sensitivity of the Roche Cobas Integra, Beckman Synchron and Biosite Triage point-of-care test were examined. HPLC Bio-Rad Remedi was chosen as the method of higher hierarchical order. The specificity of the Axsym analyzer (300 ng/ml) was 86%. At 500 ng/ml or 1000 ng/ml the specificity was increased to 99 or 100%, respectively, while the sensitivity only decreased from 97 to 91 or 81%, respectively. In summary, the cutoff concentration for amphetamine screening tests should not be below 500 ng/ml to avoid a high rate of false-positive result

Phosphate concentration in artificial tears

Background: Irrigating solutions and eye drops may contain phosphates as part of their buffer system. In the presence of epithelial keratopathy, a high concentration of phosphate favours corneal calcification. Knowledge of the phosphate concentration in artificial tear products helps to prevent this sight-threatening complication. This study gives an overview on the amount of phosphate contained in artificial tears. Methods: Fifty-nine samples of commercially available artificial tear preparations were tested. The quantification of phosphate was performed using the molybdate method on a Modular P autoanalyzer. Results: Twenty-six of 59 (44%) artificial tear products had a phosphate concentration above physiological levels (>1.45mmol/l). A phosphate concentration above 25mmol/l was found in nine products (15%), a concentration higher than 50mmol/l in three (5%). Conclusions: Many artificial tear formulations contain unphysiological levels of phosphate, but very high concentrations are found only in a few products. These preparations have the potential to favour the formation of insoluble crystalline calcium phosphate deposits when used on a damaged corneal surface, and should therefore be used cautiousl

A Comparison of Lung Function Values Among a SCUBA Diver Population and in Comparison to a Non-diver Population

The purpose of this study was to investigate possible correlations between lung function values (PEF, IRV, ERV, and FVC) among a diver population, as well as in comparison to a non-diver population. Independent variables for both populations were biological sex, age, and weekly physical activity. Independent variables for the diver population were dive tenure, number of logged dives, certification level, and gas mixture used. A spirometry test was conducted to collect lung function values of both populations. Data from this study suggest a statistically significant relationship between diver and non-diver sex and FVC, diver age and ERV, diver sex and ERV, and non-diver FVC and weekly physical activity