Publications by authors named "Maren Rohrbacher"

Reliable epidemiological information on chronic myeloproliferative disorders (CMPDs), notably Philadelphia (Ph)/BCR-ABL-positive chronic myeloid leukaemia (CML), is rare. Incidence rates vary from 0.6 to 2.

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Aim: A finite number of variants in the OPRM1, COMT, MC1R, ABCB1 and CYP2D6 genes has been identified to significantly modulate the effects of opioids in controlled homogenous settings. We analyzed the imprint of these variants in opioid therapy in a highly variable cohort of pain patients treated in outpatient units to test whether genotyping may play a role in this clinical setting.

Methods: In a multicenter study conducted in tertiary care outpatient pain centers, 352 patients (156 men and 196 women, aged 58.

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Activation of codeine by O-demethylation into morphine is a prerequisite for its analgesic effects and severe toxicity. Identifying patients in whom morphine is formed either at extremely low or at extremely high amounts may improve efficacy and safety of codeine therapy. To assess how well this identification is possible, we compared the performance of current CYP2D6 phenotype association systems (traditional genotype-based classification, a recently proposed CYP2D6 activity score, and the plasma dextromethorphan metabolic ratio) in 57 healthy Caucasians after oral administration of 30 mg dextromethorphan hydrobromide or 50 mg codeine.

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Aims: To evaluate the pharmacokinetics of nevirapine and any possible influencing factors in pregnant women (n = 16), nonpregnant women (n = 13) and men (n = 14), who received nevirapine 200 mg twice daily together with nucleoside reverse transcriptase inhibitors.

Methods: Blood samples were taken for 12 h at steady state. Nevirapine concentrations were measured by liquid chromatography-tandem mass spectrometry.

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Objectives: Three exonic single nucleotide polymorphisms (SNPs) in the cytochrome P450 2B6 (CYP2B6) gene, 516G>T, 785A>G and 1459C>T, have been described to be associated with functional changes in the CYP2B6 catalytic activity or protein expression. They are therefore of potential clinical importance for drug efficacy and safety of CYP2B6 substrates, in particular of antiretroviral therapy regimes that include efavirenz. Therefore, we aimed at providing genetic screening assays for these three SNPs.

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Introduction: Clinical evidence suggests there are three single nucleotide polymorphisms (SNPs) of the solute carrier organic anion transporter family member B1 (SLCO1B1) gene for which in vivo evidence for a functional relevance for organic anion transporter polypeptides subgroup C (OATP1B1, formerly OATP-C) has been provided. These genetic variants have been shown to lead to altered pharmacokinetics of OATP1B1 substrates, mainly pravastatin, but also the irinotecan metabolite SN-38, estrone-3-sulfate, and estradiol-17beta-glucuronide. The authors therefore developed reliable and quick screening assays to identify the SLCO1B1 SNPs -11187G>A, 388A>G and 521T>C, in order to facilitate the judgment of their clinical role and to identify allelic frequencies of SNPs and haplotypes in a Caucasian random sample.

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Objective: Our objective was to investigate whether codeine or one of its metabolites contributes substantially to central nervous effects independent from the cytochrome P450 (CYP) 2D6-mediated O-demethylation to morphine.

Methods: After oral administration of codeine, plasma concentrations of codeine and its metabolites, as well as pupil size as a measure of central nervous effects, were measured in 11 healthy volunteers representing poor, intermediate, extensive, and ultrarapid metabolizers for CYP2D6. Subsequently, the observed plasma morphine concentrations were mimicked by use of computerized morphine infusion, and the miotic effects were compared with those observed after codeine administration.

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