Alexander Paulke

Resistant hypertension? Assessment of adherence by toxicological urine analysis.

Objective: Uncontrolled hypertension under antihypertensive multidrug regimen is not necessarily always true resistance. Incomplete adherence is one of several possible causes of uncontrolled hypertension. Nonadherence remains largely unrecognized and is falsely interpreted as treatment resistance, as it is difficult to confirm or exclude objectively. This is the first study assessing adherence in patients with apparent resistant hypertension systematically via toxicological urine screening. Methods: All patients referred from primary care physicians because of uncontrolled hypertension between 2004 and 2011 were analysed. Adherence was assessed in all patients with uncontrolled hypertension despite the concurrent use of at least four antihypertensive agents by using liquid chromatography-mass spectrometry analysis for antihypertensive drugs or their corresponding metabolites in urine. Results: A total of 375 patients with uncontrolled hypertension were referred. After optimization of drug therapy and exclusion of white coat hypertension, 108 patients met criteria for resistant hypertension. Of those, 15 patients had secondary causes of hypertension and 17 achieved goal blood pressure with quadruple antihypertensive therapy. Of the remaining 76 patients, 40 patients (53%) were found to be nonadherent. Among nonadherent patients, 30% had complete and 70% had incomplete adherence; 85% of the latter had taken less than 50% of drugs prescribed. Lack of adherence was almost evenly distributed between different classes of antihypertensive drugs. Conclusion: Low adherence was the most common cause of poor blood pressure control in patients with apparent resistant hypertension, being twice as frequent as secondary causes of hypertension. Incomplete adherence was far more common than complete nonadherence; thus, assessment of adherence in patients on multiple drug regime is only reliable when all drugs are included in assessment. Assessing adherence by toxicological urine screening is a useful tool in detecting low adherence, especially in the setting of multidrug regimen as a cause of apparently resistant hypertension.

Plasma and Brain Levels of Terpene Trilactones in Rats after an Oral Single Dose of Standardized Ginkgo biloba Extract EGb 761

Several studies indicate that the terpene trilactones (TTL) of EGb 761® are responsible for most of its pharmacological action in the brain . Therefore, we investigated the ability of the TTL to cross the blood brain barrier in rats after a single oral administration (600 mg/kg) of EGb 761® and compared it with the plasma levels. In addition, we checked the pharmacokinetic characteristics of an application of EGb 761® against a similar amount of pure substances. For this purpose, we developed a sensitive HPLC-(APCI)-MS method for the determination of the Ginkgo biloba TTL (ginkgolide A [GA], B [GB], C [GC] and bilobalide [Bb]) in plasma as well as in brain tissue. The following animal study shows that the oral application of 600 mg/kg EGb 761® results in significant GA, GB, and Bb concentrations in plasma as well as in the CNS of the rodents, while the GC concentration was below the detection limit of the analytical method in both matrices. GA, GB, and Bb brain concentrations showed a rapid increase up to 55 ng/g, 40 ng/g, and 98 ng/g with no difference of the characteristic after extract or pure substance application. Regarding the plasma levels, significant higher C(max) and AUC values were detected after application of the extract EGb 761®. These results allow for the first time a discussion of pharmacological effects with the knowledge of the pharmacokinetic behavior of the TTL in target tissues.

Bodilisant-a novel fluorescent, highly affine histamine h3 receptor ligand.

A piperidine-based lead structure for the human histamine H3 receptor (hH3R) was coupled with the BODIPY fluorophore and resulted in a strong green fluorescent (quantum yield, 0.92) hH3R ligand with affinity in the nanomolar concentration range (K i hH3R = 6.51 ± 3.31 nM), named Bodilisant. Screening for affinities at histamine and dopamine receptor subtypes showed high hH3R preference. Bodilisant was used for visualization of hH3R in hH3R overexpressing HEK-293 cells with fluorescence confocal laser scanning microscopy. In addition, in native human brain tissues, Bodilisant showed clear and displaceable images of labeled hH3R.

Variable adverse effects in subjects after ingestion of equal doses of Argyreia nervosa seeds.

As the new drug Spice hit the market in 2006 and was a hot topic in the media, the general issue of legal highs has been brought to the attention of a large number of (young) people. One of these so called legal highs are the seeds of Argyreia nervosa, also known as Hawaiian Baby Woodrose, which contains the psychotropic alkaloid lysergic acid amide (LSA). A study was designed to assess how driving ability is affected by Argyreia nervosa. However, the study could not be continued due to severe adverse effects in 3 of 4 subjects, such as cardiovascular dysregulation in two and a psychosis like state in one subject. All of the participants recovered completely within 9h after ingestion. Despite body normalized doses interindividually highly differing reactions in type and intensity were observed. Furthermore, fluctuating alkaloid contents in seeds and multi-drug intoxications make the use of this legal high far more dangerous than commonly believed.

Retrospective analysis of synthetic cannabinoids in serum samples – epidemiology and consumption patterns

Herbal mixtures contain synthetic cannabinoids, which can cause severe intoxications. Due to the great variety and the changing spectrum of substances on the drug market, prevalence data are limited, and data on prevalence rates of synthetic cannabinoids in forensic cases are not available. The present study was performed to survey the prevalence of synthetic cannabinoids in cases of traffic and criminal offences in the German state Hesse in 2010. The applied analytical method covered all synthetic cannabinoids on the drug market at that time, and with 20% of the blood samples (422 out of 2201) a representative number was reanalyzed. In twelve samples synthetic cannabinoids were identified and a prevalence of 2.8% was estimated. Consumption patterns showed predominantly cases of multi-drug consumption (10 cases); the combination with cannabis or alcohol was frequent (four cases each). The observed deficits were moderate with the exception of aggravation of paranoia in one case. The symptoms were either compatible with the effects of cannabinoid agonists or attributable to alcohol or other drugs found in the blood samples. Our current analytical strategy is to perform such analyses only in cases where use is suspected or where symptoms are not explained by routine toxicological analyses. Hence, the positive rate is rather low highlighting the need to keep up with the developments on the drug market and to establish sensitive screening methods covering a broad range of substances that can be updated fast, e.g., relying on collections of mass spectrometric reference data.

A Dual Modulator of Farnesoid X Receptor and Soluble Epoxide Hydrolase To Counter Nonalcoholic Steatohepatitis

Nonalcoholic steatohepatitis arising from Western diet and lifestyle is characterized by accumulation of fat in liver causing inflammation and fibrosis. It evolves as serious health burden with alarming incidence, but there is no satisfying pharmacological therapy to date. Considering the diseases multifactorial nature, modulation of multiple targets might provide superior therapeutic efficacy. In particular, farnesoid X receptor (FXR) activation that revealed antisteatotic and antifibrotic effects in clinical trials combined with inhibition of soluble epoxide hydrolase (sEH) as anti-inflammatory strategy promises synergies. To exploit this dual concept, we developed agents exerting partial FXR agonism and sEH inhibitory activity. Merging known pharmacophores and systematic exploration of the structure-activity relationship on both targets produced dual modulators with low nanomolar potency. Extensive in vitro characterization confirmed high dual efficacy in cellular context combined with low toxicity, and pilot in vivo data revealed favorable pharmacokinetics as well as engagement on both targets in vivo.

Pharmacokinetic properties of the synthetic cannabinoid JWH-018 and of its metabolites in serum after inhalation

&NA; Each year, synthetic cannabinoids are occurring in high numbers in the illicit drug market, but data on their pharmacology and toxicology are scarcely available. Therefore, a pilot study was performed to assess adverse effects of JWH‐018, which is one of the oldest and best known synthetic cannabinoids. Six subjects inhaled smoke from 2 and 3 mg JWH‐018. The drug and nine of its metabolites were analyzed in their blood samples taken during the following 12 h by liquid chromatography–mass spectrometry (LC–MSMS). The maximum concentration of JWH‐018 reached 2.9–9.9 ng/ml after inhalation and markedly decreased during the next 1.5 h, followed by a multiexponential decline (t1/2 in median 1.3 h and 5.7 h). The concentration of the pentanoic acid metabolite was slightly higher than that of the 3‐, 4‐ and 5‐hydroxypentyl metabolites and of the 6‐hydroxyindol metabolite. The data also suggest a multiexponential decline and slow terminal elimination of JWH‐018 and all metabolites. The detection of JWH‐018 and of its metabolites in serum requires high analytical sensitivity. The pharmacokinetic properties of inhaled JWH‐018 are similar to that of THC. A slow terminal elimination of drug and metabolites may lead to accumulation in chronic users. HighlightsAfter inhalation of JWH‐018, serum concentrations are maximal within minutes.During the 12 h period a multicompartmental distribution/elimination is obvious.Pentanoic acid, 3‐, 4‐ and 5‐hydroxypentyl and 6‐hydroxyindol met. are detected.Results indicate a novel metabolite, an isomer of the pentanoic acid metabolite.A slow terminal elimination may lead to accumulation in chronic users.

Fluorescent Human EP3 Receptor Antagonists.

Exchange of the lipophilc part of ortho-substituted cinnamic acid lead structures with different small molecule fluorophoric moieties via a dimethylene spacer resulted in hEP3R ligands with affinities in the nanomolar concentration range. Synthesized compounds emit fluorescence in the blue, green, and red range of light and have been tested concerning their potential as a pharmacological tool. hEP3Rs were visualized by confocal laser scanning microscopy on HT-29 cells, on murine kidney tissues, and on human brain tissues and functionally were characterized as antagonists on human platelets. Inhibition of PGE2 and collagen-induced platelet aggregation was measured after preincubation with novel hEP3R ligands. The pyryllium-labeled ligand 8 has been shown as one of the most promising structures, displaying a useful fluorescence and highly affine hEP3R antagonists.

Rational design of a pirinixic acid derivative that acts as subtype-selective PPARγ modulator

Peroxisome proliferator-activated receptor gamma (PPARgamma) is involved in glucose and lipid homeostasis. PPARgamma agonists are in clinical use for the treatment of type 2 diabetes. Lately, a new class of selective PPARgamma modulators (SPPARgammaMs) was developed, which are believed to show less side effects than full PPARgamma agonists. We have previously shown that alpha-substitution of pirinixic acid, a moderate agonist of PPARalpha and PPARgamma, leads to low micromolar active balanced dual agonists of PPARalpha and PPARgamma. Herein we present modifications of pirinixic acid leading to subtype-selective PPARgamma agonists and furthermore the development of a selective PPARgamma modulator guided by molecular docking studies.

Studies on the alkaloid composition of the Hawaiian Baby Woodrose Argyreia nervosa, a common legal high

Seeds from the Hawaiian Baby Woodrose Argyreia nervosa of different origin and labelling and with allegedly high levels of ergot alkaloids were analysed using high performance liquid chromatography-high resolution mass spectrometry (HPLC-HRMS/MS) technique. Lysergic acid amide (LSA), ergometrine, lysergol/elymoclavine/setoclavine, chanoclavine, lysergic acid and their respective stereoisomers were identified as well as penniclavine and lysergic acid α-hydroxyethylamide. In addition, methylergometrine, methysergide, and lysergylalanine were detected, some high molecular weight ergot alkaloid derivatives and hydroxyalanine derived ergopeptide fragments were detected indicating the presence of ergopeptides in the seeds. The results of the study demonstrate that the content of ergot alkaloids in Argyreia nervosa seeds depends on the quality of the material. For a consumer the quality of the seeds is unforeseeable. For the toxicological expert it is essential to investigate not only the identity of such a confiscated seed material, but also the various ergot alkaloid constituents to assess the hazardous nature and the toxic potential of the material.