The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform
Claus Braestrup - One of the best experts on this subject based on the ideXlab platform.
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Escitalopram versus citalopram: the surprising role of the R-Enantiomer
Psychopharmacology, 2004Co-Authors: Connie Sanchez, Klaus Peter Bogeso, Bjarke Ebert, Elin Heldbo Reines, Claus BraestrupAbstract:Rationale Citalopram is a racemate consisting of a 1:1 mixture of the R (−)- and S (+)-Enantiomers. Non-clinical studies show that the serotonin reuptake inhibitory activity of citalopram is attributable to the S -Enantiomer, escitalopram. A series of recent non-clinical and clinical studies comparing escitalopram and citalopram to placebo found that equivalent doses of these two drugs, i. e. containing the same amount of the S -Enantiomer, showed better effect for escitalopram. These results suggested that the R -citalopram in citalopram inhibits the effect of the S -Enantiomer. Objective To review the pharmacological and non-clinical literature that describes the inhibition of escitalopram by R -citalopram, as well as the implications of this inhibition for the clinical efficacy of escitalopram compared to citalopram. Methods The information in this review was gathered from published articles and abstracts. Results In appropriate neurochemical, functional, and behavioural non-clinical experiments, escitalopram shows greater efficacy and faster onset of action than comparable doses of citalopram. The lower efficacy of citalopram in these studies is apparently due to the inhibition of the effect of the S -Enantiomer by the R -Enantiomer, possibly via an allosteric interaction with the serotonin transporter. Data from randomised clinical trials consistently show better efficacy with escitalopram than with citalopram, including higher rates of response and remission, and faster time to symptom relief. Conclusion The R -Enantiomer present in citalopram counteracts the activity of the S -Enantiomer, thereby providing a possible basis for the pharmacological and clinical differences observed between citalopram and escitalopram.
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escitalopram versus citalopram the surprising role of the r Enantiomer
Psychopharmacology, 2004Co-Authors: Connie Sanchez, Klaus Peter Bogeso, Bjarke Ebert, Elin Heldbo Reines, Claus BraestrupAbstract:Rationale Citalopram is a racemate consisting of a 1:1 mixture of the R(−)- and S(+)-Enantiomers. Non-clinical studies show that the serotonin reuptake inhibitory activity of citalopram is attributable to the S-Enantiomer, escitalopram. A series of recent non-clinical and clinical studies comparing escitalopram and citalopram to placebo found that equivalent doses of these two drugs, i.e. containing the same amount of the S-Enantiomer, showed better effect for escitalopram. These results suggested that the R-citalopram in citalopram inhibits the effect of the S-Enantiomer.
Bezhan Chankvetadze - One of the best experts on this subject based on the ideXlab platform.
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separation of brombuterol Enantiomers in capillary electrophoresis with cyclodextrin type chiral selectors and investigation of structure of selector selectand complexes using nuclear magnetic resonance spectroscopy
Electrophoresis, 2017Co-Authors: Ann Gogolashvili, Lali Chankvetadze, Elene Tatunashvili, Tamas Sohajda, Julianna Szeman, Antonio Salgado, Bezhan ChankvetadzeAbstract:In the present study, the Enantiomer migration order (EMO) of enilconazole in the presence of various cyclodextrins (CDs) was investigated by capillary electrophoresis (CE). Opposite EMO of enilconazole were observed when β-CD or the sulfated heptakis(2-O-methyl-3,6-di-O-sulfo)-β-CD (HMDS-β-CD) was used as the chiral selectors. Nuclear magnetic resonance (NMR) spectroscopy was used to study the mechanism of chiral recognition between enilconazole Enantiomers and those two cyclodextrins. On the basis of rotating frame nuclear Overhauser (ROESY) experiments, the structure of an inclusion complex between enilconazole and β-CD was derived, in which (+)-enilconazole seemed to form a tighter complex than the (-)-Enantiomer. This correlates well with the migration order of enilconazole Enantiomers observed in CE. No evidence of complexation between enilconazole and HMDS-β-CD could be gathered due to lack of intermolecular nuclear Overhauser effect (NOE). Most likely the interaction between enilconazole and HMDS-β-CD leads to formation of a shallow external complex that is sufficient for separation of Enantiomers in CE but cannot be evidenced based on ROESY experiment. Thus, in this particular case CE documents the presence of intermolecular interactions which are at least very difficult to be evidenced by other instrumental techniques.
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HPLC Separation of Enantiomers of Some Chiral Carboxylic Acid Derivatives Using Polysaccharide-Based Chiral Columns and Polar Organic Mobile Phases
Chromatographia, 2015Co-Authors: Iza Matarashvili, Lali Chankvetadze, Tamar Tsintsadze, Tivadar Farkas, Bezhan ChankvetadzeAbstract:The separation of Enantiomers of 14 chiral carboxylic acid derivatives was studied on six different polysaccharide-based chiral columns in high-performance liquid chromatography with methanol, ethanol and acetonitrile as mobile phases with emphasis on the elution order of Enantiomers. Some interesting examples of Enantiomer elution order reversal were observed as a function of the nature and composition of chiral selector and mobile phase. For instance, the Enantiomer elution order for carprofen, ketorolac, naproxen, proglumide and surprofen reversed with changing the chemical structure of the chiral selector. Also, the Enantiomer elution order for carprofen, ketorolac and naproxen changed by varying the composition of the mobile phase. In addition, the interesting effect of column temperature on the retention and separation of some analytes was observed. For instance, the Enantiomers of surprofen were only partially resolved at lower temperatures but baseline resolved at higher temperature.
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Enantiomer separations in capillary electrophoresis in the case of equal binding constants of the Enantiomers with a chiral selector commentary on the feasibility of the concept
Analytical Chemistry, 2004Co-Authors: Bezhan Chankvetadze, Wolfgang Lindner, Gerhard K E ScribaAbstract:It is generally acknowledged that Enantiomer separations in capillary electrophoresis are based on differences in the affinities of the analyte Enantiomers toward the chiral selector expressed as equilibrium constants of the resulting temporary diastereomeric associates. However, as can be derived from theoretical considerations, a separation of Enantiomers by CE is in principle also possible solely based on differences in the mobilities of the temporary diastereomeric complexes per se, when equal binding constants between analyte Enantiomers and the chiral selector are assumed and observed.
Connie Sanchez - One of the best experts on this subject based on the ideXlab platform.
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Escitalopram versus citalopram: the surprising role of the R-Enantiomer
Psychopharmacology, 2004Co-Authors: Connie Sanchez, Klaus Peter Bogeso, Bjarke Ebert, Elin Heldbo Reines, Claus BraestrupAbstract:Rationale Citalopram is a racemate consisting of a 1:1 mixture of the R (−)- and S (+)-Enantiomers. Non-clinical studies show that the serotonin reuptake inhibitory activity of citalopram is attributable to the S -Enantiomer, escitalopram. A series of recent non-clinical and clinical studies comparing escitalopram and citalopram to placebo found that equivalent doses of these two drugs, i. e. containing the same amount of the S -Enantiomer, showed better effect for escitalopram. These results suggested that the R -citalopram in citalopram inhibits the effect of the S -Enantiomer. Objective To review the pharmacological and non-clinical literature that describes the inhibition of escitalopram by R -citalopram, as well as the implications of this inhibition for the clinical efficacy of escitalopram compared to citalopram. Methods The information in this review was gathered from published articles and abstracts. Results In appropriate neurochemical, functional, and behavioural non-clinical experiments, escitalopram shows greater efficacy and faster onset of action than comparable doses of citalopram. The lower efficacy of citalopram in these studies is apparently due to the inhibition of the effect of the S -Enantiomer by the R -Enantiomer, possibly via an allosteric interaction with the serotonin transporter. Data from randomised clinical trials consistently show better efficacy with escitalopram than with citalopram, including higher rates of response and remission, and faster time to symptom relief. Conclusion The R -Enantiomer present in citalopram counteracts the activity of the S -Enantiomer, thereby providing a possible basis for the pharmacological and clinical differences observed between citalopram and escitalopram.
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escitalopram versus citalopram the surprising role of the r Enantiomer
Psychopharmacology, 2004Co-Authors: Connie Sanchez, Klaus Peter Bogeso, Bjarke Ebert, Elin Heldbo Reines, Claus BraestrupAbstract:Rationale Citalopram is a racemate consisting of a 1:1 mixture of the R(−)- and S(+)-Enantiomers. Non-clinical studies show that the serotonin reuptake inhibitory activity of citalopram is attributable to the S-Enantiomer, escitalopram. A series of recent non-clinical and clinical studies comparing escitalopram and citalopram to placebo found that equivalent doses of these two drugs, i.e. containing the same amount of the S-Enantiomer, showed better effect for escitalopram. These results suggested that the R-citalopram in citalopram inhibits the effect of the S-Enantiomer.
Klaus Peter Bogeso - One of the best experts on this subject based on the ideXlab platform.
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Escitalopram versus citalopram: the surprising role of the R-Enantiomer
Psychopharmacology, 2004Co-Authors: Connie Sanchez, Klaus Peter Bogeso, Bjarke Ebert, Elin Heldbo Reines, Claus BraestrupAbstract:Rationale Citalopram is a racemate consisting of a 1:1 mixture of the R (−)- and S (+)-Enantiomers. Non-clinical studies show that the serotonin reuptake inhibitory activity of citalopram is attributable to the S -Enantiomer, escitalopram. A series of recent non-clinical and clinical studies comparing escitalopram and citalopram to placebo found that equivalent doses of these two drugs, i. e. containing the same amount of the S -Enantiomer, showed better effect for escitalopram. These results suggested that the R -citalopram in citalopram inhibits the effect of the S -Enantiomer. Objective To review the pharmacological and non-clinical literature that describes the inhibition of escitalopram by R -citalopram, as well as the implications of this inhibition for the clinical efficacy of escitalopram compared to citalopram. Methods The information in this review was gathered from published articles and abstracts. Results In appropriate neurochemical, functional, and behavioural non-clinical experiments, escitalopram shows greater efficacy and faster onset of action than comparable doses of citalopram. The lower efficacy of citalopram in these studies is apparently due to the inhibition of the effect of the S -Enantiomer by the R -Enantiomer, possibly via an allosteric interaction with the serotonin transporter. Data from randomised clinical trials consistently show better efficacy with escitalopram than with citalopram, including higher rates of response and remission, and faster time to symptom relief. Conclusion The R -Enantiomer present in citalopram counteracts the activity of the S -Enantiomer, thereby providing a possible basis for the pharmacological and clinical differences observed between citalopram and escitalopram.
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escitalopram versus citalopram the surprising role of the r Enantiomer
Psychopharmacology, 2004Co-Authors: Connie Sanchez, Klaus Peter Bogeso, Bjarke Ebert, Elin Heldbo Reines, Claus BraestrupAbstract:Rationale Citalopram is a racemate consisting of a 1:1 mixture of the R(−)- and S(+)-Enantiomers. Non-clinical studies show that the serotonin reuptake inhibitory activity of citalopram is attributable to the S-Enantiomer, escitalopram. A series of recent non-clinical and clinical studies comparing escitalopram and citalopram to placebo found that equivalent doses of these two drugs, i.e. containing the same amount of the S-Enantiomer, showed better effect for escitalopram. These results suggested that the R-citalopram in citalopram inhibits the effect of the S-Enantiomer.
Bjarke Ebert - One of the best experts on this subject based on the ideXlab platform.
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Escitalopram versus citalopram: the surprising role of the R-Enantiomer
Psychopharmacology, 2004Co-Authors: Connie Sanchez, Klaus Peter Bogeso, Bjarke Ebert, Elin Heldbo Reines, Claus BraestrupAbstract:Rationale Citalopram is a racemate consisting of a 1:1 mixture of the R (−)- and S (+)-Enantiomers. Non-clinical studies show that the serotonin reuptake inhibitory activity of citalopram is attributable to the S -Enantiomer, escitalopram. A series of recent non-clinical and clinical studies comparing escitalopram and citalopram to placebo found that equivalent doses of these two drugs, i. e. containing the same amount of the S -Enantiomer, showed better effect for escitalopram. These results suggested that the R -citalopram in citalopram inhibits the effect of the S -Enantiomer. Objective To review the pharmacological and non-clinical literature that describes the inhibition of escitalopram by R -citalopram, as well as the implications of this inhibition for the clinical efficacy of escitalopram compared to citalopram. Methods The information in this review was gathered from published articles and abstracts. Results In appropriate neurochemical, functional, and behavioural non-clinical experiments, escitalopram shows greater efficacy and faster onset of action than comparable doses of citalopram. The lower efficacy of citalopram in these studies is apparently due to the inhibition of the effect of the S -Enantiomer by the R -Enantiomer, possibly via an allosteric interaction with the serotonin transporter. Data from randomised clinical trials consistently show better efficacy with escitalopram than with citalopram, including higher rates of response and remission, and faster time to symptom relief. Conclusion The R -Enantiomer present in citalopram counteracts the activity of the S -Enantiomer, thereby providing a possible basis for the pharmacological and clinical differences observed between citalopram and escitalopram.
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escitalopram versus citalopram the surprising role of the r Enantiomer
Psychopharmacology, 2004Co-Authors: Connie Sanchez, Klaus Peter Bogeso, Bjarke Ebert, Elin Heldbo Reines, Claus BraestrupAbstract:Rationale Citalopram is a racemate consisting of a 1:1 mixture of the R(−)- and S(+)-Enantiomers. Non-clinical studies show that the serotonin reuptake inhibitory activity of citalopram is attributable to the S-Enantiomer, escitalopram. A series of recent non-clinical and clinical studies comparing escitalopram and citalopram to placebo found that equivalent doses of these two drugs, i.e. containing the same amount of the S-Enantiomer, showed better effect for escitalopram. These results suggested that the R-citalopram in citalopram inhibits the effect of the S-Enantiomer.
